Bio

Clinical Focus


  • Cardiac Valve Disease
  • Thoracic Surgery
  • Aortic Aneurysm
  • Cardiovascular Surgery

Academic Appointments


Professional Education


  • Residency:Stanford University School of Medicine (1983) CA
  • Fellowship:Stanford University School of Medicine (1980) CA
  • Residency:Stanford University School of Medicine (1975) CA
  • Board Certification: Thoracic Surgery, American Board of Thoracic Surgery (1985)
  • Internship:Children's Hospital of San Francisco (1971) CA
  • Medical Education:Northwestern University Medical School (1970) IL
  • Resident, Department of Cardiovascular Surgery, Stanford University Hospital, Cardiovascular Surgery (1983)
  • Fellowship, Department of Cardiovascular Surgery, Stanford University Hospital, Vascular Surgery (1980)
  • Residency, Department of General Surgery, Stanford University Hospital, General Surgery (1978)
  • MD, Northwestern University Medical School, Medicine (1970)

Research & Scholarship

Current Research and Scholarly Interests


Research Interests: Disease of the aorta, congenital and acquired. Treatment of aortic pathology, including development of stent graft systems. Patterns of disease in patients treated with mediastinal radiation. Valvular heart disease, especially aortopathy associated with congenital bicuspid aortic valve.

Clinical Trials


  • To Evaluate the Safety and Efficacy for GORE TAG Thoracic Endoprosthesis in the Treatment of Thoracic Aortic Disease Not Recruiting

    Study Type: Interventional Study Design: Treatment, Open Label, Uncontrolled, Single Group Assignment, Safety and Efficacy study Official Title: A Clinical Study of the TAG Thoracic Endoprosthesis in the Treatment of Thoracic Aortic Diseases for Non-Surgical Candidates under the Physician Sponsored IDE. PURPOSE OF RESEARCH: You are invited to participate in a research study for treatment of aneurysms of the descending thoracic aorta. The investigational device, called the TAG Thoracic Endoprosthesis (device) has been designed to simplify treatment of aneurysms of the descending thoracic aorta. The other pathologies treated can include pseudoaneurysms, acute and chronic dissections, penetrating ulcers, mycotic aneurysms, ruptures, fistulae, and transections.The device is made from a graft (an artificial vessel) which is surrounded on the outside by a metal mesh-like form. The device is in the shape of a tube. The device reinforces the weakened part of the aorta from the inside. Blood flows through the device to the arteries that go to your abdomen and legs. The device is folded tightly onto a catheter (a flexible, hollow tube) that is put into the aorta through an artery in your leg. Unless there is a problem, you would not need to have your chest opened.

    Stanford is currently not accepting patients for this trial. For more information, please contact Archana Verma, (650) 736 - 0959.

    View full details

Teaching

2013-14 Courses


Publications

Journal Articles


  • Tirone David valve-sparing aortic root replacement and cusp repair for bicuspid aortic valve disease JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Kari, F. A., Liang, D. H., Kvitting, J. E., Stephens, E. H., Mitchell, R. S., Fischbein, M. P., Miller, D. C. 2013; 145 (3): S35-?

    Abstract

    The durability of valve-sparing aortic root replacement with or without cusp repair in patients with bicuspid aortic valve (BAV) disease is questioned. We analyzed the results of 75 patients with a BAV undergoing Tirone David reimplantation valve-sparing aortic root replacement.Average age was 45 ± 10 years; 80% were male; 31% had 2+ or greater aortic regurgitation (AR); annular diameter averaged 28 ± 3 mm; 32% had a Sievers' type 0 BAV, and 66% underwent concomitant cusp repair (usually cusp free margin shortening) to correct prolapse. Early (6 ± 3 days) and late (2.9 ± 1.7, 1-10 years) postoperative echocardiographic results were compared (cumulative echocardiographic follow-up, 190 patient-years; median late interval, 2 years [interquartile range, 0.68, 4.2]). Seven patients remained at risk beyond 6 years. Clinical outcome and valve function were analyzed using log-rank calculations.Actuarial survival was 99% ± 2%; freedom from reoperation was 90% ± 5%, infection 98% ± 2%, and stroke 100% at 6 years. After initial improvement in degree of AR (P < .001), minor subclinical progression of AR was observed (P > .5); however, freedom from AR of more than 2+ was 100%. Cusp free margin shortening was not associated with valve deterioration, but commissural suspensory polytetrafluoroethylene neochord creation (n = 4) portended a higher probability of recurrent AR (P = .025).After David procedure and cusp repair in patients with a BAV, midterm clinical and valve function outcomes were favorable out to 6 years. More follow-up is required to determine long-term valve durability and the hazard of other clinically important late adverse events, including eventual reoperation, to beyond 10 years.

    View details for DOI 10.1016/j.jtcvs.2012.11.043

    View details for Web of Science ID 000314884000009

    View details for PubMedID 23260433

  • David valve-sparing aortic root replacement: Equivalent mid-term outcome for different valve types with or without connective tissue disorder JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Kvitting, J. E., Kari, F. A., Fischbein, M. P., Liang, D. H., Beraud, A., Stephens, E. H., Mitchell, R. S., Miller, D. C. 2013; 145 (1): 117-?

    Abstract

    Although implicitly accepted by many that the durability of valve-sparing aortic root replacement in patients with bicuspid aortic valve disease and connective tissue disorders will be inferior, this hypothesis has not been rigorously investigated.From 1993 to 2009, 233 patients (27% bicuspid aortic valve, 40% Marfan syndrome) underwent Tirone David valve-sparing aortic root replacement. Follow-up averaged 4.7 ± 3.3 years (1102 patient-years). Freedom from adverse outcomes was determined using log-rank calculations.Survival at 5 and 10 years was 98.7% ± 0.7% and 93.5% ± 5.1%, respectively. Freedom from reoperation (all causes) on the aortic root was 92.2% ± 3.6% at 10 years; 3 reoperations were aortic valve replacement owing to structural valve deterioration. Freedom from structural valve deterioration at 10 years was 96.1% ± 2.1%. No significant differences were found in survival (P = .805, P = .793, respectively), reoperation (P = .179, P = .973, respectively), structural valve deterioration (P = .639, P = .982, respectively), or any other functional or clinical endpoints when patients were stratified by valve type (tricuspid aortic valve vs bicuspid aortic valve) or associated connective tissue disorder. At the latest echocardiographic follow-up (95% complete), 202 patients (94.8%) had none or trace aortic regurgitation, 10 (4.7%) mild, 0 had moderate to severe, and 1 (0.5%) had severe aortic regurgitation. Freedom from greater than 2+ aortic regurgitation at 10 years was 95.3% ± 2.5%. Six patients sustained acute type B aortic dissection (freedom at 10 years, 90.4% ± 5.0%).Tirone David reimplantation valve-sparing aortic root replacement in carefully selected young patients was associated with excellent clinical and echocardiographic outcome in patients with either a tricuspid aortic valve or bicuspid aortic valve. No demonstrable adverse influence was found for Marfan syndrome or connective tissue disorder on durability, clinical outcome, or echocardiographic results.

    View details for DOI 10.1016/j.jtcvs.2012.09.013

    View details for Web of Science ID 000312386300027

    View details for PubMedID 23083792

  • Bicuspid aortic valve configuration and aortopathy pattern might represent different pathophysiologic substrates JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Kari, F. A., Fazel, S. S., Mitchell, R. S., Fischbein, M. P., Miller, D. C. 2012; 144 (2): 516-517

    View details for DOI 10.1016/j.jtcvs.2012.05.035

    View details for Web of Science ID 000306482400046

    View details for PubMedID 22698560

  • Invited commentary. Annals of thoracic surgery Mitchell, R. S. 2012; 93 (5): 1501-?

    View details for DOI 10.1016/j.athoracsur.2012.02.043

    View details for PubMedID 22541182

  • Early outcomes of deliberate nonoperative management for blunt thoracic aortic injury in trauma JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Caffarelli, A. D., Mallidi, H. R., Maggio, P. M., Spain, D. A., Miller, D. C., Mitchell, R. S. 2010; 140 (3): 598-605

    Abstract

    Traumatic blunt aortic injury has traditionally been viewed as a surgical emergency, whereas nonoperative therapy has been reserved for nonsurgical candidates. This study reviews our experience with deliberate, nonoperative management for blunt thoracic aortic injury.A retrospective chart review with selective longitudinal follow-up was conducted for patients with blunt aortic injury. Surveillance imaging with computed tomography angiography was performed. Nonoperative patients were then reviewed and analyzed for survival, evolution of aortic injury, and treatment failures.During the study period, 53 patients with an average age of 45 years (range, 18-80 years) were identified, with 28% presenting to the Stanford University School of Medicine emergency department and 72% transferred from outside hospitals. Of the 53 patients, 29 underwent planned, nonoperative management. Of the 29 nonoperative patients, in-hospital survival was 93% with no aortic deaths in the remaining patients. Survival was 97% at a median of 1.8 years (range, 0.9-7.2 years). One patient failed nonoperative management and underwent open repair. Serial imaging was performed in all patients (average = 107 days; median, 31 days), with 21 patients having stable aortic injuries without progression and 5 patients having resolved aortic injuries.This experience suggests that deliberate, nonoperative management of carefully selected patients with traumatic blunt aortic injury may be a reasonable alternative in the polytrauma patient; however, serial imaging and long-term follow-up are necessary.

    View details for DOI 10.1016/j.jtcvs.2010.02.056

    View details for Web of Science ID 000281116000016

    View details for PubMedID 20579668

  • Invited commentary. Annals of thoracic surgery Mitchell, R. S. 2010; 90 (1): 100-?

    View details for DOI 10.1016/j.athoracsur.2010.03.089

    View details for PubMedID 20609756

  • Invited commentary. Annals of thoracic surgery Mitchell, R. S. 2010; 89 (6): 1864-1865

    View details for DOI 10.1016/j.athoracsur.2010.02.063

    View details for PubMedID 20494040

  • Infolding and collapse of thoracic endoprostheses: Manifestations and treatment options JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Sze, D. Y., Mitchell, R. S., Miller, D. C., Fleischmann, D., Frisoli, J. K., Kee, S. T., Verma, A., Sheehan, M. P., Dake, M. D. 2009; 138 (2): 324-333

    Abstract

    We sought to review the clinical sequelae and imaging manifestations of thoracic aortic endograft collapses and infoldings and to evaluate minimally invasive methods of repairing such collapses.Two hundred twenty-one Gore endografts (Excluder, TAG; W. L. Gore & Associates, Inc, Flagstaff, Ariz) were deployed in 145 patients for treatment of pathologies including aneurysms and pseudoaneurysms, dissections, penetrating ulcers, transections, fistulae, mycotic aneurysms, and neoplastic invasions in 6 different prospective trials at a single institution from 1997 to 2007. Device collapses and infoldings were analyzed retrospectively, including review of anatomic parameters, pathologies treated, device sizing and selection, clinical sequelae, methods of repair, and outcome.Six device collapses and infoldings were identified. Oversized devices placed into small-diameter aortas and imperfect proximal apposition to the lesser curvature were seen in all proximal collapses, affecting patients with transections and pseudoaneurysms. Infoldings in patients undergoing dissection represented incomplete initial expansion rather than delayed collapse. Delayed collapse occurred as many as 6 years after initial successful deployment, apparently as a result of changes in the aortic configuration from aneurysmal shrinkage. Clinical manifestations ranged from life-threatening ischemia to complete lack of symptoms. Collapses requiring therapy were remedied percutaneously by bare stenting or in one case by branch vessel embolization.Use of oversized devices in small aortas carries a risk of device failure by collapse, which can occur immediately or after years of delay. When clinically indicated, percutaneous repair can be effectively performed.

    View details for DOI 10.1016/j.jtcvs.2008.12.007

    View details for Web of Science ID 000268157800011

    View details for PubMedID 19619775

  • Factors Portending Endoleak Formation After Thoracic Aortic Stent-Graft Repair of Complicated Aortic Dissection CIRCULATION-CARDIOVASCULAR INTERVENTIONS Sze, D. Y., Van den Bosch, M. A., Dake, M. D., Miller, D. C., Hofmann, L. V., Varghese, R., Malaisrie, S. C., van der Starre, P. J., Rosenberg, J., Mitchell, R. S. 2009; 2 (2): 105-112

    Abstract

    Endoleaks after stent-graft repair of aortic dissections are poorly understood but seem substantially different from those seen after aneurysm repair. We studied anatomic and clinical factors associated with endoleaks in patients who underwent stent-graft repair of complicated type B aortic dissections.From 2000 to 2007, 37 patients underwent stent-graft repair of acute (< or =14 days; n=23), subacute (15 to 90 days; n=10) or chronic (>90 days; n=4) complicated type B aortic dissections using the Gore Thoracic Excluder (n=17) or TAG stent-grafts (n=20) under an investigator-sponsored protocol. Endoleaks were classified as imperfect proximal seal, flow through fenestrations or branches, or complex (both). Variables studied included coverage of the left subclavian artery, aortic curvature, completeness of proximal apposition, dissection chronicity, and device used. Endoleaks were found during follow-up (mean, 22 months) in 59% of patients, and they were associated with coverage of the left subclavian artery (complex, P<0.001), small radius of curvature (type 1 and complex, P=0.05), and greatest length of unapposed proximal stent graft (complex, P<0.0001). During follow-up, 10 endoleaks resolved spontaneously, 6 required reintervention for false lumen dilatation, and 2 were stable without clinical consequences.Endoleaks are common after stent-graft repair of aortic dissection and may lead to false lumen enlargement necessitating reintervention. Anatomic complexities such as acute aortic curvature and covered side branches were associated with endoleaks, illustrating the need for dissection-specific device development.

    View details for DOI 10.1161/CIRCINTERVENTIONS.108.819722

    View details for Web of Science ID 000276051600005

    View details for PubMedID 20031703

  • Improvement in coronary anastomosis with cardiac surgery simulation JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Fann, J. I., Caffarelli, A. D., Georgette, G., Howard, S. K., Gaba, D. M., Youngblood, P., Mitchell, S., Burdon, T. A. 2008; 136 (6): 1486-1491

    Abstract

    Cardiac surgery trainees might benefit from simulation training in coronary anastomosis and more advanced procedures. We evaluated distributed practice using a portable task station and experience on a beating-heart model in training coronary anastomosis.Eight cardiothoracic surgery residents performed 2 end-to-side anastomoses with the task station, followed by 2 end-to-side anastomoses to the left anterior descending artery by using the beating-heart model at 70 beats/min. Residents took home the task station, recording practice times. At 1 week, residents performed 2 anastomoses on the task station and 2 anastomoses on the beating-heart model. Performances of the anastomosis were timed and reviewed.Times to completion for anastomosis on the task station decreased 20% after 1 week of practice (351 +/- 111 to 281 +/- 53 seconds, P = .07), with 2 residents showing no improvement. Times to completion for beating-heart anastomosis decreased 15% at 1 week (426 +/- 115 to 362 +/- 94 seconds, P = .03), with 2 residents demonstrating no improvement. Home practice time (90-540 minutes) did not correlate with the degree of improvement. Performance rating scores showed an improvement in all components. Eighty-eight percent of residents agreed that the task station is a good method of training, and 100% agreed that the beating-heart model is a good method of training.In general, distributed practice with the task station resulted in improvement in the ability to perform an anastomosis, as assessed by times to completion and performance ratings, not only with the task station but also with the beating-heart model. Not all residents improved, which is consistent with a "ceiling effect" with the simulator and a "plateau effect" with the trainee. Simulation can be useful in preparing residents for coronary anastomosis and can provide an opportunity to identify the need and methods for remediation.

    View details for DOI 10.1016/j.jtcvs.2008.08.016

    View details for Web of Science ID 000261970100016

    View details for PubMedID 19114195

  • Complicated acute type B aortic dissection: Midterm results of emergency endovascular stent-grafting JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Verhoye, J. P., Miller, D. C., Sze, D., Dake, M. D., Mitchell, R. S. 2008; 136 (2): 424-430

    Abstract

    This study assessed midterm results of emergency endovascular stent-grafting for patients with life-threatening complications of acute type B aortic dissection.Between November 1996 and June 2004, 16 patients with complicated acute type B aortic dissections (mean age 57 years, range 16-88 years) underwent endovascular stent-grafting within 48 hours of presentation. Complications included contained rupture, hemothorax, refractory chest pain, and severe visceral or lower limb ischemia. Stent-graft types included custom-made first-generation endografts and second-generation commercial stent-grafts (Gore Excluder or TAG; W. L. Gore & Associates, Inc, Flagstaff, Ariz.). Follow-up was 100% complete, averaged 36 +/- 36 months, and included postprocedural surveillance computed tomographic scans.Early mortality was 25% +/- 11% (70% confidence limit), with no late deaths. No new neurologic complications occurred. According to the latest scan, 4 patients (25%) had complete thrombosis of the false lumen; the lumen was partially thrombosed in 6 patients (38%). Distal aortic diameter was increased in only 1 patient. Actuarial survival at 1 and 5 years was 73% +/- 11%; freedom from treatment failure (including aortic rupture, device fault, reintervention, aortic death, or sudden, unexplained late death) was 67% +/- 14% at 5 years.With follow-up to 9 years, endovascular stent-grafting for patients with complicated acute type B aortic dissection conferred benefit. Consideration of emergency stent-grafting may improve the dismal outlook for these patients; future refinements in stent-graft design and technology and earlier diagnosis and intervention should be associated with improved results.

    View details for DOI 10.1016/j.jtcvs.2008.01.046

    View details for Web of Science ID 000258535300026

    View details for PubMedID 18692652

  • Treatment of acute type b aortic dissection: New and improved? JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Mitchell, R. S. 2008; 135 (6): 1201-1201

    View details for DOI 10.1016/j.jtcvs.2007.07.072

    View details for Web of Science ID 000256494200003

    View details for PubMedID 18544353

  • The aortopathy of bicuspid aortic valve disease has distinctive patterns and usually involves the transverse aortic arch JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Fazel, S. S., Mallidi, H. R., Lee, R. S., Sheehan, M. P., Liang, D., Fleischman, D., Herfkens, R., Mitchell, S., Miller, D. C. 2008; 135 (4): 901-U54

    Abstract

    Bicuspid aortic valves are associated with a poorly characterized connective tissue disorder that predisposes to aortic catastrophes. Because no criterion exists dictating the appropriate extent of aortic resection in aneurysmal disease of the bicuspid aortic valve, we studied the patterns of aortic dilation in this population.Sixty-four patients with bicuspid aortic valves who underwent computed tomographic or magnetic resonance angiography and echocardiography were retrospectively identified between January 2002 and March 2006. Orthonormal 2-dimensional or 3-dimensional aortic diameters were measured at 10 levels. Agglomerative hierarchic clustering with centered correlation distance measurements and complete linkage analysis was used to detect distinct patterns of aortic dilatation.Mean aortic diameter was 28.1 +/- 0.7 mm at the annulus and 21.7 +/- 0.4 mm at the diaphragmatic hiatus. The aorta was largest in the tubular ascending aorta (45.9 +/- 1.0 mm). Compared with the descending aorta, the transverse aortic arch was also dilated (P < .01). Cluster analysis showed 4 patterns of aortic dilatation: cluster I, aortic root alone (n = 8, 13%); cluster II, tubular ascending aorta alone (n = 9, 14%); cluster III, tubular portion and transverse arch (n = 18, 28%); and, cluster IV, aortic root and tubular portion with tapering across the transverse arch (n = 29, 45%).Distinct patterns of aortic dilatation in patients with bicuspid aortic valves call for an individualized degree of aortic replacement to minimize late aortic complications and reoperation. Patients in clusters III and IV should have transverse arch replacement (plus concomitant root replacement in cluster IV). Patients in cluster I should undergo complete aortic root replacement, whereas in patients in cluster II supracommissural ascending aortic grafting is adequate.

    View details for DOI 10.1016/j.jtcvs.2008.01.022

    View details for Web of Science ID 000254423600028

    View details for PubMedID 18374778

  • Invited commentary. Annals of thoracic surgery Mitchell, R. S. 2008; 85 (2): 464-?

    View details for DOI 10.1016/j.athoracsur.2007.11.034

    View details for PubMedID 18222244

  • Acute aortic syndromes: new insights from electrocardiographically gated computed tomography. Seminars in thoracic and cardiovascular surgery Fleischmann, D., Mitchell, R. S., Miller, D. C. 2008; 20 (4): 340-347

    Abstract

    The development of retrospective electrocardiographic (ECG)-gating has proved to be a diagnostic and therapeutic boon for computed tomography (CT) imaging of patients with acute thoracic aortic diseases, such as aortic dissection/intramural hematoma (AD/IMH), penetrating atherosclerotic ulcer (APU), and ruptured/leaking aneurysm. The notorious pulsation motion artifacts in the ascending aorta confounding regular CT scanning can be eliminated, and involvement of the sinuses of Valsalva, the valve cusps, the aortic annulus, and the coronary arteries in aortic dissection can be clearly depicted or excluded. Motion-free images also allow reliable identification of the site of the primary intimal tear, the location, and extent of the intimomedial flap, and branch artery involvement. ECG-gated CTA also allows the detection of more subtle lesions and variants of aortic dissection, which may ultimately expand our understanding of these complex, life-threatening disorders.

    View details for DOI 10.1053/j.semtcvs.2008.11.011

    View details for PubMedID 19251175

  • Pre- and postoperative imaging of the aortic root for valve-sparing aortic root repair (V-SARR). Seminars in thoracic and cardiovascular surgery Fleischmann, D., Liang, D. H., Mitchell, R. S., Miller, D. C. 2008; 20 (4): 365-373

    Abstract

    Valve-sparing aortic root repair (V-SARR) using the David reimplantation method is an increasingly popular alternative to composite valve graft aortic root replacement in patients with aortic root aneurysms or dissections who wish to avoid anticoagulation. Computed tomography (CT) with retrospective electrocardiograph (ECG)-gating has become routine before and following V-SARR at Stanford. CT allows accurate measurement of aortic dimensions and provides unprecedented three-dimensional (3D) images of the sinuses, the aortic valve cusps, and coronary arteries in patients with the Marfan syndrome (MFS), with a bicuspid aortic valve (BAV), or other aortic diseases. This helps the surgeon to conceptualize the size of the aortic grafts required and how much reduction is necessary proximally (aortic annulus) and distally. These maneuvers are used to reduce the aortic annular diameter (when necessary) and replace the sinuses and ascending aorta (T. David-V, Stanford modification V-SARR). Postoperative ECG-gated CT confirms the reconstructed geometry and reliably detects coronary or other anastomotic problems.

    View details for DOI 10.1053/j.semtcvs.2008.11.009

    View details for PubMedID 19251178

  • Intraoperative monitoring of elephant trunk kinking with transesophageal echocardiography JOURNAL OF CARDIOTHORACIC AND VASCULAR ANESTHESIA Oakes, D. A., Sze, D. Y., Frisoli, J. K., Mitchell, R. S., Harris, E. J., Thu, C., van der Starre, P. J. 2007; 21 (4): 584-586

    View details for DOI 10.1053/j.jvca.2006.11.002

    View details for Web of Science ID 000248766100023

    View details for PubMedID 17678793

  • Rapid aneurysmal degeneration of a Stanford type B aortic dissection in a patient with Loeys-Dietz syndrome JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Lee, R. S., Fazel, S., Schwarze, U., Fleischmann, D., Berry, G. J., Liang, D., Miller, D. C., Mitchell, R. S. 2007; 134 (1): 242-U32

    View details for DOI 10.1016/j.jtcvs.2007.03.004

    View details for Web of Science ID 000247595300041

    View details for PubMedID 17599521

  • Invited commentary. Annals of thoracic surgery Mitchell, R. S. 2007; 83 (5): 1640-?

    View details for PubMedID 17462372

  • Stent-graft repair of an aortic rupture caused by invasive hemangiopericytoma ANNALS OF THORACIC SURGERY van der Starre, P. J., Sze, D. Y., Guta, C., Mitchell, R. S., Dake, M. D. 2006; 81 (6): 2300-2302

    Abstract

    We describe a patient with a history of hemangiopericytoma, who had hemoptysis develop due to a pseudoaneurysm of the thoracic aorta from an intrathoracic metastasis. Stent-graft repair successfully excluded the aneurysm from the aorta. Transesophageal echocardiography showed to be an important guide for correct placement of the device.

    View details for DOI 10.1016/j.athoracsur.2005.07.016

    View details for Web of Science ID 000238027600059

    View details for PubMedID 16731179

  • Unusual case of late thoracic stent graft failure after cardioversion ANNALS OF THORACIC SURGERY Caffarelli, A. D., BANOVAC, F., Cheung, S. C., Fleischmann, D., Mitchell, R. S. 2006; 81 (5): 1875-1877

    Abstract

    We report the unusual case of successful endovascular exclusion of a thoracic aortic aneurysm with subsequent thoracic aortic aneurysm reduction, and development of an interval, acute type III endoleak after cardioversion 5 years after stent graft deployment.

    View details for DOI 10.1016/j.athoracsur.2005.04.087

    View details for Web of Science ID 000237001700052

    View details for PubMedID 16631691

  • Third International Summit on thoracic aortic endografting: Lessons from long-term results of thoracic stent-graft repairs JOURNAL OF ENDOVASCULAR THERAPY Mitchell, R. S., Ishimaru, S., Criado, F. J., Ehrlich, M. P., Ivancev, K., Lachat, M., Malina, M., May, J., Orend, K. H., Rousseau, H., Williams, D. M. 2005; 12 (1): 89-97

    View details for Web of Science ID 000226954100014

    View details for PubMedID 15683277

  • Midterm results of endovascular repair of descending thoracic aortic aneurysms with first-generation stent grafts JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Demers, P., Miller, D. C., Mitchell, R. S., Kee, S. T., Sze, D., Razavi, M. K., Dake, M. D. 2004; 127 (3): 664-673

    Abstract

    Five years after reporting our initial stent-graft repair of descending thoracic aortic aneurysms experience, we determined the 5- to 10-year results of stent-graft treatment and identified risk factors for adverse late outcomes.Between 1992 and 1997, 103 patients (mean age 69 +/- 12 years) underwent repair using first-generation (custom-fabricated) stent grafts. Sixty-two patients (60%) were unsuitable candidates for conventional open surgical repair ("inoperable"). Follow-up was 100% complete (mean 4.5 +/- 2.5 years; maximum 10 years). Outcome variables included death and treatment failure (endoleak, aortic rupture, reintervention, and/or aortic-related or sudden death).Overall actuarial survival was 82% +/- 4%, 49% +/- 5%, and 27% +/- 6% at 1, 5, and 8 years. Survival in open surgical candidates was 93% +/- 4% and 78% +/- 6% and at 1 and 5 years compared with 74% +/- 6% and 31% +/- 6% in those deemed inoperable (P <.001). Independent risk factors for death were older age (hazard ratio = 1.1; P =.008), previous stroke (hazard ratio = 2.8; P =.003), and being designated an inoperable candidate (hazard ratio = 1.9; P =.04). Actuarial freedom from aortic reintervention and treatment failure at 8 years was 70% +/- 6% and 39% +/- 8%, respectively. Earlier operative year (hazard ratio = 1.2; P =.07), larger distal landing zone diameter (hazard ratio = 1.1; P =.001), and transposition of the left subclavian artery (hazard ratio = 3.3; P =.008) were determinants of treatment failure.Survival after aneurysm repair using crude, first-generation stent grafts was satisfactory in good operative candidates but bleak in the inoperable cohort, raising the question of whether asymptomatic patients should have even been treated. Late aortic complications were detected in many patients, reemphasizing the importance of serial imaging surveillance.

    View details for DOI 10.1016/j.jtcvs.2003.10.047

    View details for Web of Science ID 000220115400013

    View details for PubMedID 15001894

  • Stent-graft repair of penetrating atherosclerotic ulcers in the descending thoracic aorta: Mid-term results ANNALS OF THORACIC SURGERY Demers, P., Miller, D. C., Mitchell, R. S., Kee, S. T., Chagonjian, L., Dake, M. D. 2004; 77 (1): 81-86

    Abstract

    Localized aortic pathoanatomic abnormalities are good targets for endovascular stent-grafting but only short-term results have been reported. Our objective was to determine the effectiveness of endovascular stent-graft treatment of patients with descending thoracic atherosclerotic penetrating atherosclerotic ulcers (PAU) and to identify risk factors for treatment failure.Between 1993 and 2000 endovascular repair of PAU with first-generation (custom-fabricated) and second-generation (commercial) stent-grafts was performed in 26 patients (mean age, 70 years), 6 (23%) of whom had rupture. Fourteen patients (54%) were not candidates for open surgical repair. Follow-up was 100% complete (average, 51 months; maximum, 114 months). Outcome variables considered in the multivariable analysis included death and treatment failure (composite end-point comprising early death, endoleak, stent-graft mechanical fault, late aortic event, reintervention, and aortic-related or sudden death).Three patients (12% +/- 7% [+/-70% confidence limits]) died within 30 days and 2 had an early type I endoleak. Primary success rate was 92%. Actuarial survival estimates at 1, 3, and 5 years were 85% +/- 8%, 76% +/- 8% and 70% +/- 10% respectively and actuarial freedom from treatment failure was 81% +/- 8%, 71% +/- 9% and 65% +/- 10%. Multivariable analyses identified previous cerebrovascular accident (hazard ratio [HR] 17.1, p = 0.02) and female sex (HR 7.4, p = 0.08) as independent risk factors for death. For treatment failure the predictors were increasing aortic diameter (HR 1.1 [per mm above the mean value], p = 0.01) and female sex (HR 5.5, p = 0.09).Endovascular stent-graft repair is effective but not curative treatment for selected, high surgical risk, elderly patients with a descending aortic PAU over the medium term. Assiduous serial follow-up imaging after stent-grafting is mandatory to detect late complications especially in those with a large aorta.

    View details for DOI 10.1016/S0003-4975(03)00816-6

    View details for Web of Science ID 000187735800017

    View details for PubMedID 14726040

  • Acute type A aortic dissection complicated by aortic regurgitation: Composite valve graft versus separate valve graft versus conservative valve repair JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Lai, D. T., Miller, D. C., Mitchell, R. S., Oyer, P. E., Moore, K. A., Robbins, R. C., Shumway, N. E., Reitz, B. A. 2003; 126 (6): 1978-1986

    Abstract

    To clarify the merits of various surgical approaches, we studied the outcome after composite valve graft versus separate valve and graft replacement versus conservative valve treatment with replacement of the ascending aorta in patients with acute type A aortic dissection complicated by aortic regurgitation.Between 1967 and 1999, 123 patients (mean age 56 +/- 15 years) underwent composite valve graft replacement (n = 21), separate valve and graft replacement (n = 20), or conservative valve treatment (n = 82 [commissural resuspension in 46]); follow-up averaged 6.5 years (95% complete).The 30-day, 1-year, and 6-year survival estimates of 85% +/- 4%, 79% +/- 5%, and 69% +/- 5% (+/-1 standard error of mean), respectively, after conservative valve treatment were similar to 86% +/- 8%, 81% +/- 9%, and 65% +/- 16%, respectively, with composite valve graft replacement and better (but insignificantly so) than 70% +/- 10%, 70% +/- 10%, and 45% +/- 11%, respectively, with separate valve and graft replacement. The 6-year freedom from proximal reoperation was 95% +/- 3%, 89% +/- 10%, and 100% in conservative valve graft, separate valve and graft, and composite valve graft subgroups, respectively (P = not significant). Cox regression multivariable analysis identified that previous sternotomy (hazard ratio [or e(beta)] 95% confidence interval 1.4-10.9, P =.006), hypertension (0.99-2.9, P =.05), cardiac tamponade (1.1-4.0, P =.03), and stroke (1.7-7.0, P =.001) increased the hazard of death. No factors predicting a higher likelihood of late proximal reoperation were identified.In patients with acute type A aortic dissection and aortic regurgitation, there was no significant difference in overall survival or reoperation rates among these surgical approaches. We try to save the valve whenever possible unless the aortic root is pathologically dilated (eg, Marfan syndrome or annuloaortic ectasia) or destroyed by the dissection process, when composite valve graft or valve-sparing aortic root replacement is indicated.

    View details for DOI 10.1016/S0022-5223(03)01279-0

    View details for Web of Science ID 000187560400047

    View details for PubMedID 14688716

  • Femoro-femoral partial bypass in the treatment of thoracoabdominal aneurysms. Seminars in thoracic and cardiovascular surgery Coady, M. A., Mitchell, R. S. 2003; 15 (4): 340-344

    Abstract

    This article describes our rationale for the use of femoro-femoral bypass as a primary modality for perfusion in the repair of thoracoabdominal aortic aneurysms at Stanford University School of Medicine. Benefits and limitations of this method are discussed and compared with other described techniques.

    View details for PubMedID 14710375

  • Cavoatrial tumor thrombus excision without circulatory arrest UROLOGY Shinghal, R., Vricella, L. A., Mitchell, R. S., Presti, J. 2003; 62 (1): 138-140

    Abstract

    Traditional methods of cavoatrial thrombus excision use deep hypothermic circulatory arrest with significant associated morbidity and mortality. We describe a novel technique that avoids circulatory arrest, yet provides a bloodless field for tumor excision.A 59-year-old woman presented with a left renal mass and tumor thrombus with extension into the right atrium. After left radical nephrectomy, an aortic occlusion balloon was placed in the abdominal aorta at the level of the diaphragm, limiting flow in the inferior vena cava for tumor excision and maintaining both cerebral and spinal cord perfusion during cardiopulmonary bypass. Tumor excision was successfully performed using this technique with minimal postoperative morbidity in the patient described. She remained free of recurrence at 9 months of follow-up.Cavoatrial tumor thrombus excision can be successfully performed without deep hypothermic circulatory arrest.

    View details for DOI 10.1016/S0090-4295(03)00258-9

    View details for Web of Science ID 000183892600036

    View details for PubMedID 12837443

  • Is medical therapy still the optimal treatment strategy for patients with acute type B aortic dissections? JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Umana, J. P., Lai, D. T., Mitchell, R. S., Moore, K. A., Rodriguez, F., Robbins, R. C., Oyer, P. E., Dake, M. D., Shumway, N. E., Reitz, B. A., Miller, D. C. 2002; 124 (5): 896-910

    Abstract

    The optimal treatment of patients with acute type B dissections continues to be debated.A 36-year clinical experience of medical and surgical treatments in 189 patients was retrospectively analyzed (multivariable Cox proportional hazards model) with respect to three outcome end points: all deaths, freedom from reoperation, and freedom from late aortic complications or death. Propensity score analysis identified 2 quintiles (quintiles I and II, consisting of 142 comparable patients) for further comparison of the effects of surgical versus medical treatment.Shock (hazard ratio 14.5, 95% confidence interval 4.7-44.5, P <.001) and visceral ischemia (hazard ratio 10.9, 95% confidence interval 3.9-30.3, P <.001) largely predominated as determinants of death, along with 6 other risk factors (arch involvement, rupture, stroke, previous sternotomy, and coronary or lung disease), which roughly doubled the hazard of death. Female sex was a significant but weaker predictor of death. Renal dysfunction, year of presentation, age, and mode of therapy (medical vs surgical) had no important bearing on overall survival. The actuarial survival estimates for all patients were 71%, 60%, 35%, and 17% at 1, 5, 10, and 15 years, respectively, and were similar for the medical and surgical patients. Reoperation and late aortic complications were predicted by the presence of Marfan syndrome. For the propensity-matched patients in quintiles I and II, survival, freedom from reoperation, and freedom from aortic complications were almost identical in the medically treated and surgical subsets.The prognosis for patients with acute type B aortic dissection is bleak and determined primarily by dissection-related and patient-specific risk factors, which do not appear to be readily modifiable.

    View details for DOI 10.1067/mtc.2002.123131

    View details for Web of Science ID 000179012300006

    View details for PubMedID 12407372

  • What is the best treatment for patients with acute type B aortic dissections - Medical, surgical, or endovascular stent-grafting? ANNALS OF THORACIC SURGERY Umana, J. P., Miller, D. C., Mitchell, R. S. 2002; 74 (5): S1840-S1843

    Abstract

    Controversy continues regarding treatment for patients with acute type B aortic dissection.One hundred eighty-nine patients with acute type B aortic dissection managed over a 36-year period were analyzed retrospectively for three outcome endpoints: survival; freedom from reoperation, and freedom from late aortic-related complications or late death. Risk factors for death were identified using a multivariable Cox proportional hazards model. Then to account for patient selection bias, heterogeneity of the population, and continuous evolution in techniques, propensity score analysis was used to identify risk-matched cohorts (quintiles I and II) in which the results of medical (n = 111) or surgical (n = 31) therapy were compared more comprehensively.The two main determinants of death were shock (hazard ratio [HR] = 14.5, 95% confidence level [CL] 4.7, 44.5; p < 0.001) and visceral ischemia (HR = 10.9, 95% CL 3.9, 30.3; p < 0.001). Arch involvement, rupture, stroke, previous sternotomy, and coronary or lung disease roughly doubled the hazard. Female sex was also a significant but weaker independent predictor of death. Actuarial survival estimates for all patients were 71%, 60%, 35%, and 17% at 1, 5, 10, and 15 years, respectively, and were similar for the medical and surgical patients. The Marfan syndrome predicted reoperation and late aortic complications or late death. In a separate analysis of the 142 patients in quintiles I and II, survival, freedom from reoperation, as well as freedom from late aortic complications or death were almost identical in the medical and surgical subsets.The poor long-term prognosis of patients with acute type B aortic dissection is determined primarily by dissection-related and patient-specific risk factors, which are not readily modifiable. Whether the outlook in the future will be improved using stent-grafts remains to be determined.

    View details for Web of Science ID 000179262300107

    View details for PubMedID 12440677

  • Stent grafts for the thoracic aorta: A new paradigm? ANNALS OF THORACIC SURGERY Mitchell, R. S. 2002; 74 (5): S1818-S1820

    Abstract

    The treatment of thoracic aortic pathology is complicated by the morbidity of the surgical procedure, and the comorbidities encountered in an elderly population. Stent grafts have now been used for approximately 10 years for the treatment of thoracic aneurysmal disease, management of aortic dissections, intramural hematoma, and giant penetrating ulcers, and for traumatic aortic tears, with impressive early results. However, these efforts have been significantly limited by the lack of a commercially available stent graft specifically designed for the thoracic aorta, the lack of real long-term follow-up, and the failure of experience in the abdominal aorta to translate to the thoracic aorta. Nevertheless, significant and even unique therapies have been enabled by stent graft technology for the treatment of the above-mentioned diseases. It is likely that, with more sophisticated technology and improved understanding of thoracic aortic pathology, stent graft use will expand, and its utility will be further clarified.

    View details for Web of Science ID 000179262300102

    View details for PubMedID 12440673

  • Does profound hypothermic circulatory arrest improve survival in patients with acute type a aortic dissection? Circulation Lai, D. T., Robbins, R. C., Mitchell, R. S., Moore, K. A., Oyer, P. E., Shumway, N. E., Reitz, B. A., Miller, D. C. 2002; 106 (12): I218-28

    Abstract

    No evidence exists that profound hypothermic circulatory arrest (PHCA) improves survival or reduces the likelihood of distal aortic reoperation in patients with acute type A aortic dissection.Records of 307 patients with acute type A aortic dissection from 1967 to 1999 were retrospectively reviewed. The influence of repair using PHCA (n=121) versus without PHCA (n=186) on death and freedom from distal aortic reoperation was analyzed using multivariable Cox regression models. Propensity score analysis identified a subset of 152 comparable patients in 3 quintiles (QIII-V) in which the effects of PHCA (n=113) versus no PHCA (n=39) were further compared.For all patients, 30-day, 1-year, and 5-year survival estimates were 81+/-2%, 74+/-3%, and 63+/-3% (+/-1 SE). Survival rates and actual freedom from distal aortic reoperation was not significantly different between treatment methods in the entire patient cohort nor in the matched patients in quintiles III-V. Treatment method was not associated with differences in early major complications, late survival, or distal aortic reoperation rates in the entire patient sample or in quintiles III-V.Aortic repair with or without circulatory arrest was associated with comparable early complications, survival, and distal aortic reoperation rates in patients with acute type A aortic dissection. Despite the lack of concrete evidence favoring the use of PHCA, it does no harm, and most of our group uses PHCA regularly because of its practical technical advantages and theoretical potential merit.

    View details for PubMedID 12354737

  • Prognosis of aortic intramural hematoma with and without penetrating atherosclerotic ulcer - A clinical and radiological analysis CIRCULATION Ganaha, F., Miller, C., Sugimoto, K., Do, Y. S., Minamiguchi, H., Saito, H., Mitchell, R. S., Dake, M. D. 2002; 106 (3): 342-348

    Abstract

    Advances in imaging techniques have increased the recognition of aortic intramural hematomas (IMHs) and penetrating atherosclerotic ulcers (PAUs); however, distinction between IMH and PAU remains unclear. We intended to clarify differences between IMH coexisting with PAU and IMH not associated with PAU by comparisons of clinical features, imaging findings, and patient outcome to derive the optimal therapeutic approach.We performed a retrospective analysis of 65 symptomatic patients with aortic IMH. There were 34 patients with IMH associated with PAU (group 1) and 31 patients with IMH unaccompanied by PAU (group 2). Involvement of the ascending aorta (type A) was more frequent in group 2 (8 of 31, 26%), whereas most of the patients in group 1 had exclusive involvement of the descending aorta (type B) (31of 34, 91%). Patients were subdivided into 2 categories, those with clinical progression and those with stable disease. Forty-eight percent of patients in group 1 and 8% in group 2 were in the progressive category (P=0.002). Clinical and radiological findings were compared between those group 1 patients who had a progressive disease course (n=12) and those who were stable (n=13). Sustained or recurrent pain (P<0.0001), increasing pleural effusion (P=0.0003), and both the maximum diameter (P=0.004) and maximum depth (P=0.003) of the PAU were reliable predictors of disease progression.This study suggests a difference in disease behavior that argues for the prognostic importance of making a clear distinction between IMH caused by PAU and IMH not associated with PAU. IMH with PAU was significantly associated with a progressive disease course, whereas IMH without PAU typically had a stable course, especially when limited to the descending thoracic aorta.

    View details for DOI 10.1161/01.CIR.0000022164.26075.5A

    View details for Web of Science ID 000176944300015

    View details for PubMedID 12119251

  • Thoracic aortic stent-grafts CORONARY ARTERY DISEASE Umana, J. P., Mitchell, R. S. 2002; 13 (2): 103-111

    View details for Web of Science ID 000175470200005

    View details for PubMedID 12004262

  • Treatment of endocarditis with valve replacement: The question of tissue versus mechanical prosthesis ANNALS OF THORACIC SURGERY Moon, M. R., Miller, D. C., Moore, K. A., Oyer, P. E., Mitchell, R. S., Robbins, R. C., Stinson, E. B., Shumway, N. E., Reitz, B. A. 2001; 71 (4): 1164-1171

    Abstract

    It remains unknown whether there is any important clinical advantage to the use of either a bioprosthetic or mechanical valve for patients with native or prosthetic valve endocarditis.Between 1964 and 1995, 306 patients underwent valve replacement for left-sided native (209 patients) or prosthetic (97 patients) valve endocarditis. Mechanical valves were implanted in 65 patients, bioprostheses in 221 patients, and homografts in 20 patients.Operative mortality was 18+/-2% and was independent of replacement valve type (p > 0.74). Long-term survival was superior for patients with native valve endocarditis (44+/-5% at 20 years) compared with those with prosthetic valve endocarditis (16+/-7% at 20 years) (p < 0.003). Survival was independent of valve type (p > 0.27). The long-term freedom from reoperation for patients who received a biologic valve who were younger than 60 years of age was low (51+/-5% at 10 years, 19+/-6% at 15 years). For patients older than 60 years, however, freedom from reoperation with a biological valve (84+/-7% at 15 years) was similar to that for all patients with mechanical valves (74+/-9% at 15 years) (p > 0.64).Mechanical valves are most suitable for younger patients with native valve endocarditis; however, tissue valves are acceptable for patients greater than 60 years of age with native or prosthetic valve infections and for selected younger patients with prosthetic valve infections because of their limited life expectancy.

    View details for Web of Science ID 000168590600017

    View details for PubMedID 11308154

  • Endovascular treatment of aortic dissections and thoracic aortic aneurysms. Seminars in vascular surgery Umana, J. P., Mitchell, R. S. 2000; 13 (4): 290-298

    Abstract

    Diseases of the thoracic aorta pose a significant challenge to the surgeon because of the complexity of the disease and the characteristics of the patient population. Frequent comorbidities and increasing age account for mortality rates between 5% and 20% for surgical repair of descending thoracic aortic aneurysms and in excess of 50% for Stanford type B aortic dissections, when complicated by preoperative end-organ ischemia. Endovascular techniques of fenestration, stenting, and stent-grafting have emerged as viable alternatives to conventional surgery in these patients. The authors review their experience using endovascular stent-grafts in the treatment of 103 patients with descending thoracic aortic aneurysms and 19 patients with acute aortic dissections. Fenestration and stenting are also addressed as adjuvant therapies in the treatment of complicated aortic dissections. Actuarial survival for aneurysms was 81% +/- 5% at 1 year and 73% +/- 5% at 2 years. Stent-grafting for acute aortic dissections achieved instant relief of symptoms in 71% of cases with an early procedural mortality of 16%, and endovascular revascularization of ischemic beds was achieved in 93% +/- 4% of cases of peripheral or visceral ischemia. The authors' experience supports the use of endovascular techniques in the treatment of thoracic aortic pathologic conditions. Longer follow-up and results of ongoing trials that use newer devices will help define the indications for their future use.

    View details for PubMedID 11156057

  • Endovascular repair of abdominal aortic aneurysms: Eligibility rate and impact on the rate of open repair JOURNAL OF VASCULAR SURGERY Wolf, Y. G., Fogarty, T. J., Olcott, C., Hill, B. B., Harris, E. J., Mitchell, R. S., Miller, D. C., Dalman, R. L., Zarins, C. K. 2000; 32 (3): 519-523

    Abstract

    The purpose of this study was to determine the rate of eligibility among patients with abdominal aortic aneurysms (AAAs) considered for endovascular repair and to examine the effect of an endovascular program on the institutional pattern of AAA repair.All patients evaluated for endovascular AAA repair since the inception of an endovascular program were reviewed for determination of eligibility rates and eventual treatment. Open AAA repairs were categorized as simple (uncomplicated infrarenal), complex (juxtarenal, suprarenal, thoracoabdominal, infected), or ruptured, and their rates before and after initiation of an endovascular program were compared.Over 3 years, 324 patients were considered for endovascular AAA repair; 176 (54%) were candidates, 138 (43%) were not candidates, and 10 (3%) did not complete the evaluation. The rate of eligibility increased significantly from 45% (66/148 patients) during the first half of this period to 63% (110/176 patients) during the second half (P <. 001). Candidates were significantly younger (74.4 +/- 7.6 years) than noncandidates (78.3 +/- 6.7 years) (P <.01), and their aneurysm diameter tended to be smaller (57.6 +/- 9.2 mm compared with 60.8 +/- 12.3 mm; P =.06). The most common reason for ineligibility was an inadequate proximal aortic neck. Of 176 candidates, 78% underwent endovascular repair, and 6% underwent open repair. Of 138 noncandidates, 56% underwent surgical repair. Over a period of 6 years, 542 patients with AAAs (429 simple, 86 complex, 27 ruptured) underwent open repair. The total number and ratio of simple to complex open repairs for nonruptured aneurysms during the 3 years before the initiation of the endovascular program (213 simple, 44 complex) were not significantly different from the repairs over the subsequent 3-year period (216 simple, 42 complex). Similarly, no difference in the total number and the ratio of simple to complex open repairs was found between the first and the second 18-month periods since the initiation of the endovascular program.The rate of eligibility of patients with AAA for endovascular repair appears to be higher than previously reported. The presence of an active endovascular program has not decreased the number or shifted the distribution of open AAA repair.

    View details for Web of Science ID 000089230100023

    View details for PubMedID 10957658

  • Endovascular solutions for diseases of the thoracic aorta. Cardiology clinics Mitchell, R. S. 1999; 17 (4): 815-?

    Abstract

    Technology is proceeding at a very brisk pace. Harnessing that technology for clinical use is both a challenge and an opportunity. This combination of surgical and interventional methods has allowed for improved clinical outcomes in certain complex aortic problems. This article explores and discusses new techniques used in detection and treatment of diseases of the thoracic aorta.

    View details for PubMedID 10589348

  • Endovascular stent-graft placement for the treatment of acute aortic dissection NEW ENGLAND JOURNAL OF MEDICINE Dake, M. D., Kato, N., Mitchell, R. S., Semba, C. P., Razavi, M. K., Shimono, T., Hirano, T., Takeda, K., Yada, I., Miller, D. C. 1999; 340 (20): 1546-1552

    Abstract

    The standard treatment for acute aortic dissection is either surgical or medical therapy, depending on the morphologic features of the lesion and any associated complications. Irrespective of the form of treatment, the associated mortality and morbidity are considerable.We studied the placement of endovascular stent-grafts across the primary entry tear for the management of acute aortic dissection originating in the descending thoracic aorta. We evaluated the feasibility, safety, and effectiveness of transluminal stent-graft placement over the entry tear in 4 patients with acute type A aortic dissections (which involve the ascending aorta) and 15 patients with acute type B aortic dissections (which are confined to the descending aorta). Dissections involved aortic branches in 14 of the 19 patients (74 percent), and symptomatic compromise of multiple branch vessels was observed in 7 patients (37 percent). The stent-grafts were made of self-expanding stainless-steel covered with woven polyester or polytetrafluoroethylene material.Placement of endovascular stent-grafts across the primary entry tears was technically successful in all 19 patients. Complete thrombosis of the thoracic aortic false lumen was achieved in 15 patients (79 percent), and partial thrombosis was achieved in 4 (21 percent). Revascularization of ischemic branch vessels, with subsequent relief of corresponding symptoms, occurred in 76 percent of the obstructed branches. Three of the 19 patients died within 30 days, for an early mortality rate of 16 percent (95 percent confidence interval, 0 to 32 percent). There were no deaths and no instances of aneurysm or aortic rupture during the subsequent average follow-up period of 13 months.These initial results suggest that stent-graft coverage of the primary entry tear may be a promising new treatment for selected patients with acute aortic dissection. This technique requires further evaluation, however, to assess its therapeutic potential fully.

    View details for Web of Science ID 000080358900004

    View details for PubMedID 10332016

  • The "first generation" of endovascular stent-grafts for patients with aneurysms of the descending thoracic aorta JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Dake, M. D., Miller, D. C., Mitchell, R. S., Semba, C. P., Moore, K. A., Sakai, T. 1998; 116 (5): 689-703

    Abstract

    Our goal was to determine whether endovascular stent-grafting is feasible and effective for patients with aneurysms of the descending thoracic aorta.Starting in July 1992, we conducted a prospective, uncontrolled clinical trial in 103 patients (mean age 69 years [range 34-89 years]) who underwent endovascular treatment of aneurysms of the descending thoracic aorta using a custom-fabricated, self-expanding stent-graft device. Follow-up was 100% complete and averaged 22 months. Sixty-two patients (60%) were judged not to be reasonable candidates for a conventional "open" surgical procedure.Complete thrombosis of the aneurysm was ultimately achieved in 86 (83%) patients. The early mortality rate was 9% +/- 3% (+/- 70% CL). Multivariable analysis revealed that myocardial infarction or stroke was linked with a higher likelihood of early death (P = .001). Early serious complications included paraplegia in 3% +/- 2% and stroke in 7% +/- 3%. Actuarial survival estimates at 1 year and 2 years were 81% +/- 4% and 73% +/- 5% (+/- 1 SE), respectively; being judged not to be a surgical candidate portended a higher probability of death (P = .003). According to the intent-to-treat principle, "treatment failure" (including all late sudden unexplained deaths) occurred in 38 patients; 53% +/- 10% of patients were free from treatment failure at 3.7 years. Stent-graft related complications occurred commonly and were linked with several anatomic, technical, and patient-related risk factors.This 5-year clinical trial involving use of a "first generation" device indicates that endovascular stent-grafting of descending thoracic aortic aneurysms is feasible with acceptable medium-term results. More refined, commercially developed devices available today offer less traumatic and more precise stent-graft deployment; these major technical advantages, coupled with important lessons we have learned over time and better patient selection, should be associated with more salutary clinical results in the future.

    View details for Web of Science ID 000076693300002

    View details for PubMedID 9806376

  • Aneurysm of an aberrant right subclavian artery: Treatment with PTFE covered stentgraft JOURNAL OF VASCULAR SURGERY Davidian, M., Kee, S. T., Kato, N., Semba, C. P., Razavi, M. K., Mitchell, R. S., Dake, M. D. 1998; 28 (2): 335-339

    View details for Web of Science ID 000075344600021

    View details for PubMedID 9719329

  • Treatment of aortoiliac aneurysms with use of single-piece tapered stent-grafts JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kato, N., Dake, M. D., Semba, C. P., Razavi, M. K., Kee, S. T., Slonim, S. M., Samuels, S. L., Terasaki, K. K., Zarins, C. K., Mitchell, R. S., Miller, D. C. 1998; 9 (1): 41-49

    Abstract

    The authors describe their experience with the use of single-piece, tapered stent-grafts for the treatment of abdominal aortic or aortoiliac aneurysms.Single-piece, tapered stent-grafts were placed in 15 patients for the treatment of abdominal aortic aneurysms with small distal necks (n = 13), and aortoiliac aneurysms (n = 2). There were 13 men and two women who ranged in age from 59 to 83 years (mean, 71 years). Usual open surgery was considered high risk in all patients because of comorbid medical conditions. The stent-grafts were made of Z stents covered with polytetrafluoroethylene (PTFE). Additional stent-grafts needed to treat perigraft leaks were made of Z stents covered with woven polyester (n = 5), Wallstents covered with PTFE (n = 2), Z stents covered with PTFE (n = 1), and a PTFE-covered Palmaz stent (n = 1). After stent-graft placement, the contralateral iliac artery was occluded by a blocking device composed of either a PTFE-covered Palmaz (n = 1) or Z stent (n = 13), and a femoral-femoral bypass was created.After placement of the stent-grafts, immediate perigraft leaks were observed in eight patients (53%). These were at the proximal (n = 5) or the distal end (n = 3). All, except one, were treated successfully with additional stent-grafts. The one failure was in a patient who developed aortic rupture after balloon dilation, requiring open surgical repair. Second procedures were required in four patients (27%), including three leaks treated successfully with coil embolization and/or a back-up stent-graft, and one stent-graft migration and thrombosis treated by thrombolysis and placement of an additional stent-graft. One patient died of respiratory failure 23 days after placement of the stent-graft. The mean follow-up was 12 months (range, 4-26 months). On the last follow-up, the aneurysms in the 13 living patients remained thrombosed.Treatment of aortoiliac aneurysms with use of single-piece, tapered stent-grafts is feasible in selected patients. The morbidity and mortality rates compare favorably with those of the open surgical procedures in a high-risk population. Further improvements in the technique and longer follow-up data are needed before this procedure can be recommended for the treatment of all aortoiliac aneurysms.

    View details for Web of Science ID 000071543100006

    View details for PubMedID 9468394

  • Mycotic aneurysms of the thoracic aorta: Repair with use of endovascular stent-grafts JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Semba, C. P., Sakai, T., Slonim, S. M., Razavi, M. K., Kee, S. T., Jorgensen, M. J., Hagberg, R. C., Lee, G. K., Mitchell, R. S., Miller, D. C., Dake, M. D. 1998; 9 (1): 33-40

    Abstract

    Standard therapy of mycotic aneurysms in the descending aorta consists of thoracotomy and in situ graft placement or extraanatomic bypass. The alternative use of endovascular stent-grafts was evaluated for management of infected aneurysms of the thoracic aorta.In a retrospective analysis during a 5-year period, 112 patients underwent stent-graft placement for thoracic aortic aneurysms. Three patients (mean age, 68.6; range, 64-70 years) had mycotic thoracic aneurysms. Stent-grafts were constructed from Z stents covered with polyester fabric and were delivered remotely through a catheter under fluoroscopic guidance.Complete thrombosis of the mycotic aneurysms was achieved in all patients. One patient required a second separate stent-graft placement procedure because of migration of the initial device; the second patient underwent surgical repair of a ruptured mycotic abdominal aortic aneurysm followed immediately by stent-graft placement for a chronic mycotic thoracic aneurysm; a third patient underwent repair of two infected false aneurysms secondary to complete rupture of a surgical interposition graft. There were no complications of persistent bacteremia despite placement of the stent-graft device at the site of primary infection, reinfection, delayed rupture, paraplegia, distal emboli, or surgical conversion. One patient died of cardiac arrest at 25 months; there were no perioperative deaths (< or = 30 days). The remaining two patients were alive and well at median follow-up of 24 months (range, 4-25 months).Endovascular stent-grafts combined with antibiotic therapy may be an alternative to conventional thoracotomy in managing mycotic aneurysms of the descending thoracic aorta.

    View details for Web of Science ID 000071543100005

    View details for PubMedID 9468393

  • Traumatic thoracic aortic aneurysm: Treatment with endovascular stent-grafts RADIOLOGY Kato, N., Dake, M. D., Miller, D. C., Semba, C. P., Mitchell, R. S., Razavi, M. K., Kee, S. T. 1997; 205 (3): 657-662

    Abstract

    To demonstrate the feasibility and safety of endovascular stent-graft placement for treatment of traumatic aortic aneurysm.Ten patients with traumatic aortic aneurysm were treated with endovascular stent-grafts. Three patients had an acute traumatic aneurysm; seven had a chronic aneurysm. Stent-grafts were constructed from modified Z-stents covered with woven polyester or expanded polytetrafluoroethylene graft material and were deployed through a 20-24-F delivery sheath in an exposed artery located remotely from the lesion.Stent-graft placement and thrombosis of the aneurysmal sac were successful in all patients. Major complications were encountered in three patients after endovascular treatment. One patient had a peri-graft leak; complete thrombosis of the aneurysmal sac was achieved after coil embolization of the leak. Transposition of the left subclavian artery was necessary to relieve left arm ischemia in another patient. In the third patient, stent placement in the left main stem bronchus was needed to relieve left lung atelectasis. All patients were alive and without complications during the follow-up period (mean, 15 months).Transluminal placement of endovascular stent-grafts is a technically feasible method for treatment of traumatic thoracic aortic aneurysm and may be an effective alternative to open-chest surgery.

    View details for Web of Science ID A1997YG85000007

    View details for PubMedID 9393517

  • Stent-graft repair of thoracic aortic aneurysms. Seminars in vascular surgery Mitchell, R. S., Miller, D. C., Dake, M. D. 1997; 10 (4): 257-271

    Abstract

    Aneurysmal disease of the thoracic aorta continues to be a very challenging management problem for physicians because of the many comorbidities harbored by these patients, as well as the morbidity of the conventional open repair via left thoracotomy. In a combined effort between interventional radiology and cardiovascular surgery, an endovascular stent graft repair has been devised for these patients in an effort to reduce morbidity. This report documents the results in the first 108 patients so treated. The graft itself, custom-made for each individual, is composed of interlocked, self-expanding "Z" stents covered with a woven Dacron graft. Compressed in a loading capsule, the graft can then be advanced through a 27-French (outside diameter; OD) sheath, which is positioned within the aneurysm under fluoroscopic guidance. Relatively normal 2- to 3-cm segments of proximal and distal aorta allow an adequate friction seal to prevent stent graft dislodgement and also provide a hemostatic seal to obliterate aneurysm filling. Complete aneurysm thrombosis was achieved primarily in 103 patients. There were 10 deaths (9.25%) within the first 30 days, four of which were directly attributable to the stent graft procedure. Perioperative strokes occurred in four patients, and there were four instances of paraplegia. There have been two documented stent graft failures in a mean follow-up of 21.8 months (range, 1 to 57 months). Although the long-term durability of this procedure remains unknown, we believe this less invasive endovascular approach will prove to be an effective and less morbid treatment for aneurysmal disease of the descending thoracic aorta.

    View details for PubMedID 9431597

  • Composite valve graft versus separate aortic valve and ascending aortic replacement: is there still a role for the separate procedure? Circulation Yun, K. L., Miller, D. C., Fann, J. I., Mitchell, R. S., Robbins, R. C., Moore, K. A., Oyer, P. E., Stinson, E. B., Shumway, N. E., Reitz, B. A. 1997; 96 (9): II-368 75

    Abstract

    To ascertain if operative technique has any bearing on outcome, the surgical results after aortic root replacement using either a composite valve graft (CVG) or a separate graft and valve (GV) were analyzed.Three hundred and ninety consecutive, nonrandomized patients treated for aortic valve disease and ascending aortic aneurysm (n=278) or type A dissection (n=112 [45 acute]) between 1965 and 1995 were analyzed retrospectively. One hundred and thirty-five patients received a CVG, and 255 had separate GV replacement. Mean age was 52+/-16 years (+/-1 SD). Eighty-two patients (44% of the CVG group) had the Marfan syndrome (MFS). Follow-up (96% complete) totaled 2247 patient-years and extended to 27 years. The operative mortality rate was 10+/-3% (+/-70% confidence limits) for patients receiving a CVG and 15+/-2% for GV replacement (P=NS). The 15-year actuarial survival estimate was higher for the CVG group (53+/-14% [+/-SEM] versus 36+/-4%, P=.037). Seven patients in the CVG group required reoperation on the aortic valve or ascending aorta, as did 49 in the GV group. The probabilities of freedom from reoperation on the aortic rootwere 82+/-9% and 75+/-4% at 10 years for the CVG and GV group (P=NS). Thirty variables were analyzed in a multivariate model: pulmonary disease, higher New York Heart Association functional class, and longer cardiopulmonary bypass time were linked with higher operative mortality risk; older age, emergency operation, coronary artery disease, and liver dysfunction were independent determinants of late death. Younger age and use of a bioprosthesis were predictors of late reoperation. Type of procedure (GV versus CVG) was not a significant predictor of any outcome variable.The long-term results after CVG or GV were similar, which reflects proper patient selection. Use of a composite valve graft theoretically confers more protection against recurrent aortic root aneurysm, and, unless one opts for a valve-sparing aortic root replacement procedure, is most appropriate for younger patients, those with the MFS (including acute dissections), and others with marked pathological involvement of the sinuses. On the other hand, use of a separate GV should not be abandoned; in carefully selected patients (and if properly performed, eg, excision of the sinuses), GV also provides satisfactory results.

    View details for PubMedID 9386126

  • Endovascular stent graft repair of thoracic aortic aneurysms. Seminars in thoracic and cardiovascular surgery Mitchell, R. S. 1997; 9 (3): 257-268

    Abstract

    Aneurysmal disease of the thoracic aorta continues to present vexing challenges to the aortic surgeon. Not only does the incidence of the disease seem to be increasing, but the older population also harbors more comorbidities. In an effort to reduce the perioperative mortality and morbidity, surgeons and interventional radiologists at Stanford University Medical Center devised a less invasive, endovascular stent-graft repair. This report details the results of the first 81 patients, and reviews some other pertinent developments. The stent-graft is composed of interlocked, self-expanding "Z" stents covered with a woven Dacron graft, which can then be introduced through a hollow 27F Teflon sheath under fluoroscopic guidance and deployed across the aneurysm. Aneurysms of the descending thoracic aorta are most easily treated, but distal arch pathology can occasionally be accommodated. A friction seal prevents movement of the stent, and complete exclusion of the aneurysm sac from the circulation is usually possible. Degenerative aneurysms accounted for the majority of the diseased aortas. Results: There were 7 (9% +/- 3%) deaths, 3 directly attributable to the stent-graft procedure, including two strokes presumably from atheroemboli from the aortic arch. Paraplegia occurred in three patients, but in only one with an uncomplicated stent-graft placement without protracted hypotension. Two nonfatal strokes also occurred. There has been only a single instance of documented late graft failure, which resulted in a fatal hemorrhage. Although the long-term durability of the stent-grafts in unknown at this early stage, we believe this technology to be a significantly less morbid treatment for aneurysmal disease of the descending thoracic aorta. Only long-term follow-up will further define its utility.

    View details for PubMedID 9263344

  • Acute rupture of the descending thoracic aorta: Repair with use of endovascular stent-grafts JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Semba, C. P., Kato, N., Kee, S. T., Lee, G. K., Mitchell, R. S., Miller, D. C., Dake, M. D. 1997; 8 (3): 337-342

    Abstract

    To describe the use of endovascular stent-grafts to treat acute ruptures of the descending thoracic aorta as an alternative to surgery in high-risk patients.From July 1992 to August 1996, 95 patients underwent stent-grafting of the descending thoracic aorta for a variety of lesions. Of these, 11 patients with acute (< or = 7 days) rupture from aneurysms (n = 8) or trauma (n = 3) underwent repair with use of endovascular stent-grafts. Rupture was confirmed with preoperative imaging studies and occurred in the mediastinum (n = 9), the pleural space (n = 1), or the lung (n = 1). All patients were considered high surgical risk due to generalized cardiopulmonary disease and/or previous thoracotomies. Stent-grafts were constructed from Z stents covered with polyester fabric and delivered through a catheter under fluoroscopic control from a remote access site.Stent-graft deployment was successful in all patients. There were no complications of perigraft leak, stent migration, paraplegia, or intraoperative death. Two patients died in the follow-up period: one of ventricular perforation during unrelated thoracic surgery for tumor resection (day 1) and one of cardiac arrest (day 28). All others are alive (mean follow-up, 15.1 months).For acute rupture of the thoracic aorta, endovascular stent-graft repair is technically feasible and may be a therapeutic alternative to a surgical interposition graft in patients considered high risk for conventional thoracotomy. Long-term studies are necessary to determine the role of stent-grafts in preventing future aortic rupture.

    View details for Web of Science ID A1997WY51200004

    View details for PubMedID 9152904

  • Thoracic aortic aneurysm repair with endovascular stent-grafts. Vascular medicine Semba, C. P., Mitchell, R. S., Miller, D. C., Kato, N., Kee, S. T., Chen, J. T., Dake, M. D. 1997; 2 (2): 98-103

    Abstract

    The purpose of the study was to describe the clinical experience is using endoluminal stent-grafts for the treatment of thoracic aortic aneurysms in high-risk patients. Patients with aneurysms of the descending thoracic aorta who were considered high surgical risks underwent evaluation for endoluminal repair. The prosthesis was constructed from Z stents covered with polyester fabric using dimensions based upon preprocedural computed tomography scans and angiography. Through a femoral arteriotomy or left retroperitoneal flank incision, a 22-24 Fr delivery catheter was inserted and advanced through the aorta to the target site under fluoroscopic guidance in the operating suite. The stent-graft prosthesis was deployed at the site of the aneurysm. 44 patients (36 male, 8 female; mean age 36 years) underwent stent-graft repair for thoracic aneurysms (mean diameter 6.3 cm). The deployment was technically successful in all cases, with complete aneurysm thrombosis in 88%. The 30-day perioperative mortality rate was 6.8% and 35-month actuarial survival was 82%. There were no cases of stent migration, surgical conversion or intraprocedural death. Paraplegia occurred in two patients who underwent simultaneous surgical infrarenal aortic aneurysm repair immediately followed by stent-graft placement for a coexisting thoracic aneurysm. The conclusion was that placement of endoluminal stent-grafts for repair of thoracic aortic aneurysms is technically feasible in high-risk patients in whom conventional surgery is contraindicated. Long-term studies are needed to determine protection against aneurysm rupture and patient survival.

    View details for PubMedID 9546963

  • Accuracy of biplane and multiplane transesophageal echocardiography in diagnosis of typical acute aortic dissection and intramural hematoma JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY Keren, A., Kim, C. B., Hu, B. S., Eyngorina, I., Billingham, M. E., Mitchell, R. S., Miller, D. C., Popp, R. L., Schnittger, I. 1996; 28 (3): 627-636

    Abstract

    The purpose of this study was to evaluate the diagnostic accuracy of biplane and multiplane transesophageal echocardiography in patients with suspected aortic dissection, including intramural hematoma.Transesophageal echocardiography is a useful technique for rapid bedside evaluation of patients with suspected acute aortic dissection. The sensitivity of transesophageal echocardiography is high, but the diagnostic accuracy of biplane and multiplane transesophageal echocardiography for dissection and intramural hematoma is less well defined.We studied 112 consecutive patients at a major referral center who had undergone biplane or multiplane transesophageal echocardiography to identify aortic dissection. The presence, absence and type of aortic dissection (type A or B, typical dissection or intramural hematoma) were confirmed by operation or autopsy in 60 patients and by other imaging techniques in all. The accuracy of transesophageal echocardiography for ancillary findings of aortic dissection (intimal flap, fenestration and thrombosis) was assessed in the 60 patients with available surgical data.Of the 112 patients, aortic dissection was present in 49 (44%); 10 of these had intramural hematoma (5 with and 5 without involvement of the ascending aorta). Of the remaining 63 patients without dissection, 33 (29%) had aortic aneurysm and 30 (27%) had neither dissection nor aneurysm. The overall sensitivity and specificity of transesophageal echocardiography for the presence of dissection were 98% and 95%, respectively. The specificity for type A and type B dissection was 97% and 99%, respectively. The sensitivity and specificity for intramural hematoma was 90% and 99%, respectively. The accuracy of transesophageal echocardiography for diagnosis of acute significant aortic regurgitation and pericardial tamponade was 100%.Biplane and multiplane transesophageal echocardiography are highly accurate for prospective identification of the presence and site of aortic dissection, its ancillary findings and major complications in a large series of patients with varied aortic pathology. Intramural hematoma carries a high complication rate and should be treated identically with aortic dissection.

    View details for Web of Science ID A1996VE27300013

    View details for PubMedID 8772749

  • Endoluminal aortic grafting: A preliminary animal study of graft healing JOURNAL OF SURGICAL RESEARCH Harris, E. J., Harris, E. J., Berry, G. J., Mitchell, R. S. 1996; 61 (2): 404-412

    Abstract

    Our purpose was to evaluate the placement, long term performance, and healing of a transluminally delivered endoluminal graft and attachment system, in an animal model using large adult sheep. Nineteen sheep in the weight range of 105-125 kg were entered into this study. Under fluoroscopic guidance in anesthetized animals, an endoluminal delivery system was inserted through a common femoral arteriotomy into the infrarenal aorta, and the graft and attachment system were deployed. Fixation of the proximal and distal ends of the graft to the aortic wall was achieved by hooks on the self expanding attachment system, and seated by balloon expansion. Explantation of the prosthesis was performed prior to euthanasia at 1-, 3-, and 6-month intervals. Aortograms were obtained before and after implantation and before explantation for evaluation of placement, patency, anastomotic seal, migration, and graft infolding. In situ gross examination of the prosthesis under anesthesia prior to sacrifice was performed in all animals. Histologic sections were obtained from both attachment sites ("anastomoses"), from the midgraft and hook insertion sites, and from normal aorta inferior and superior to the endoluminal prosthesis. Scanning electron microscopy was performed randomly on specimens derived from the superior and inferior anastomotic sites at each time point. Selected intervals of healing were 1 month (N=5), 3 months (N=5), and 6 months (N=8). One sheep was euthanized at 1 week due to paraplegia. At all intervals, all prostheses were patent, were well incorporated at the aortic wall-anastomotic sites, and were without mural thrombus. The attachment hooks penetrated the aortic adventitia in all animals. There was no graft migration. At one month, initial pannus formation covered the anastomoses and the entire luminal graft, yet the endothelial-like surface coverage was incomplete. At 3 months and at 6 months, the anastomoses and luminal surfaces displayed more uniform pannus and endothelial-like surface coverage. We conclude that this endoluminal delivery system, passed through a femoral arteriotomy, can effectively deploy an endoluminal graft with self expanding attachment system having consistent patency, secure fixation, and incorporation of the anastomoses with the aortic wall in this animal model.

    View details for Web of Science ID A1996TZ90100018

    View details for PubMedID 8656616

  • Port-access coronary artery bypass grafting: A proposed surgical method JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Stevens, J. H., Burdon, T. A., Peters, W. S., Siegel, L. C., Pompili, M. F., Vierra, M. A., STGOAR, F. G., Ribakove, G. H., Mitchell, R. S., Reitz, B. A. 1996; 111 (3): 567-573

    Abstract

    Minimally invasive surgical methods have been developed to provide patients the benefits of open operations with decreased pain and suffering. We have developed a system that allows the performance of cardiopulmonary bypass and myocardial protection with cardioplegic arrest without sternotomy or thoracotomy. In a canine model, we successfully used this system to anastomose the internal thoracic artery to the left anterior descending coronary artery in nine of 10 animals. The left internal thoracic artery was dissected from the chest wall, and the pericardium was opened with the use of thoracoscopic techniques and single lung ventilation. The heart was arrested with a cold blood cardioplegic solution delivered through the central lumen of a balloon occlusion catheter (Endoaortic Clamp; Heartport, Inc., Redwood City, Calif.) in the ascending aorta, and cardiopulmonary bypass was maintained with femorofemoral bypass. An operating microscope modified to allow introduction of the 3.5x magnification objective into the chest was positioned through a 10 mm port over the site of the anastomosis. The anastomosis was performed with modified surgical instruments introduced through additional 5 mm ports. In the cadaver model (n = 7) the internal thoracic artery was harvested and the pericardium opened by means of similar techniques. A precise arteriotomy was made with microvascular thoracoscopic instruments under the modified microscope on four cadavers. In three other cadavers we assessed the exposure provided by a small anterior incision (4 to 6 cm) over the fourth intercostal space. This anterior port can assist in dissection of the distal internal thoracic artery and provides direct access to the left anterior descending, circumflex, and posterior descending arteries. We have demonstrated the potential feasibility of grafting the internal thoracic artery to coronary arteries with the heart arrested and protected, without a major thoracotomy or sternotomy.

    View details for Web of Science ID A1996UB98000013

    View details for PubMedID 8601971

  • MR and cerebrospinal fluid enzymes as sensitive indicators of subclinical cerebral injury after open-heart valve replacement surgery AMERICAN JOURNAL OF NEURORADIOLOGY Steinberg, G. K., Delapaz, R., Mitchell, R. S., Bell, T. E., Albers, G. W. 1996; 17 (2): 205-212

    Abstract

    To evaluate MR imaging and lumbar cerebrospinal fluid enzymes as potential sensitive indicators of cerebral injury after open-heart valve replacement surgery.Thirty-four patients with cardiac valvular disease were prospectively entered into this study and then underwent valve replacement or repair under cardiopulmonary bypass using a membrane oxygenator. In 26 patients, MR head images were obtained 12 to 24 hours before surgery; repeat MR images were obtained between 1 and 2 weeks after surgery. In 18 patients, lumbar puncture cerebrospinal fluid was analyzed 24 to 48 hours after surgery; the analyses included measurement of lactic dehydrogenase, creatine phosphokinase, adenylate kinase, and neuron-specific enolase.After surgery, MR imaging showed new ischemic lesions in 15 (58%) of 26 patients: 7 with deep white matter hyperintense lesions; 5 with brain stem, caudate, cerebellar, or thalamic/basal ganglia infarcts; 1 with intraparenchymal hemorrhage; 1 with a subdural hematoma and cortical infarct; and 1 with a corpus callosum lesion consistent with calcium or air. These new ischemic lesions seen on MR images were associated with a focal neurologic deficit in only 4 (27%) of the 15 patients. Neuron-specific enolase and lactic dehydrogenase were abnormally elevated after surgery in 5 (28%) of 18 patients. Adenylate kinase and creatine phosphokinase (brain isozymes) were elevated in one (67%) of the patients. Two (40%) of the five patients with abnormally high neuron-specific enolase or lactic dehydrogenase after surgery also showed a new focal neurologic deficit.MR imaging is a sensitive measure of subclinical cerebral ischemia after cardiac valve replacement under cardiopulmonary bypass. Cerebrospinal fluid neuron-specific enolase and lactic dehydrogenase are less sensitive than MR imaging for detecting subclinical cerebral ischemia, but these values were elevated after surgery more frequently than was adenylate kinase in our patients.

    View details for Web of Science ID A1996TW23400001

    View details for PubMedID 8938287

  • SURGICAL-MANAGEMENT OF AORTIC DISSECTION DURING A 30-YEAR PERIOD CIRCULATION Fann, J. I., Smith, J. A., Miller, D. C., Mitchell, R. S., Moore, K. A., Grunkemeier, G., Stinson, E. B., Oyer, P. E., Reitz, B. A., Shumway, N. E. 1995; 92 (9): 113-121
  • Surgical management of aortic dissection during a 30-year period. Circulation Fann, J. I., Smith, J. A., Miller, D. C., Mitchell, R. S., Moore, K. A., Grunkemeier, G., Stinson, E. B., Oyer, P. E., Reitz, B. A., Shumway, N. E. 1995; 92 (9): II113-21

    Abstract

    Certain recent studies have demonstrated improved surgical outcome in patients with aortic dissection. We analyzed the surgical survival rates of patients with acute aortic dissections and the late prognosis of those with aortic dissection during a 30-year period.Between 1963 and 1992, 360 patients (256 men and 104 women; mean +/- 1 SD age, 57 +/- 14 years) underwent surgery for aortic dissection: 174 patients had an acute type A (AcA), 46 an acute type B (AcB), 106 a chronic type A (ChA), and 34 a chronic type B (ChB) aortic dissection. The overall operative mortality rate was 24 +/- 8% (26 +/- 3% for AcA, 39 +/- 8% for AcB, 17 +/- 4% for ChA, and 15 +/- 6% for ChB, [+/- 70% confidence limit]). The operative mortality rates for patients with acute aortic dissection (AcA or AcB) were assessed for five time "windows": 1963 to 1972 (42 +/- 8%), 1973 to 1977 (37 +/- 8%), 1978 to 1982 (15 +/- 6%), 1983 to 1987 (27 +/- 6%), and 1988 to 1992 (26 +/- 6%). Logistic regression analysis suggested that the low operative mortality rate during the 1978-to-1982 interval occurred by chance. Multivariate analysis showed earlier operative year, hypertension, cardiac tamponade, renal dysfunction, and older age were independent determinants of operative death. Actuarial survival rates (including early deaths) after 5, 10, and 15 years for AcA patients were 55%, 37%, and 24%; for AcB, 48%, 29%, and 11%; for ChA, 65%, 45%, and 27%; and for ChB, 59%, 45%, and 27%. Multivariate analysis revealed that older age and previous operation were significant predictors for late death. Freedom from reoperation for all patients was 84%, 67%, and 57% at 5, 10, and 15 years, respectively.Although the operative mortality rate decreased over time for patients with aortic dissection, the risk for those with acute aortic dissection during the last 10 years (1983 to 1992) is probably more realistic than that observed in the preceding 5-year interval (1978 to 1982). The operative mortality rates for patients with chronic aortic dissection have remained relatively static. Earlier diagnosis of acute aortic dissection before development of cardiac tamponade and renal impairment is critical to improve the operative salvage rate. Long-term outcome still is not optimal, which emphasizes the need for better serial postoperative aortic imaging surveillance and medical follow-up and blood pressure control.

    View details for PubMedID 7586393

  • TRANSLUMINAL PLACEMENT OF ENDOVASCULAR STENT-GRAFTS FOR THE TREATMENT OF DESCENDING THORACIC AORTIC-ANEURYSMS NEW ENGLAND JOURNAL OF MEDICINE Dake, M. D., Miller, D. C., Semba, C. P., Mitchell, R. S., Walker, P. J., Liddell, R. P. 1994; 331 (26): 1729-1734

    Abstract

    The usual treatment for thoracic aortic aneurysms is surgical replacement with a prosthetic graft, but the associated morbidity and mortality are considerable. We studied the use of transluminally placed endovascular stent-graft devices as an alternative to surgical repair.We evaluated the feasibility, safety, and effectiveness of transluminally placed stent-graft to treat descending thoracic aortic aneurysms in 13 patients over a 24-month period. Atherosclerotic, anastomotic, and post-traumatic true or false aneurysms and aortic dissections were treated. The mean diameter of the aneurysms was 6.1 cm (range, 5 to 8). The endovascular stent-grafts were custom-designed for each patient and were constructed of self-expanding stainless-steel stents covered with woven Dacron grafts.Endovascular placement of the stent-graft prosthesis was successful in all patients. There was complete thrombosis of the thoracic aortic aneurysm surrounding the stent-graft in 12 patients, and partial thrombosis in 1. Two patients initially had small, residual patent proximal tracts into the aneurysm sac, but both tracts thrombosed within two months after the procedure. In four patients, two prostheses were required to bridge the aneurysm adequately. There have been no deaths or instances of paraplegia, stroke, distal embolization, or infection during an average follow-up of 11.6 months. One patient with an extensive chronic aortic dissection required open surgical graft replacement four months later because of progressive dilatation of the arch.These preliminary results demonstrate that endovascular stent-graft repair is safe in highly selected patients with descending thoracic aortic aneurysms. This new method of treatment will, however, require careful long-term evaluation.

    View details for Web of Science ID A1994PZ26600001

    View details for PubMedID 7984192

  • Surgical management of aortic dissection in patients with the Marfan syndrome. Circulation Smith, J. A., Fann, J. I., Miller, D. C., Moore, K. A., DeAnda, A., Mitchell, R. S., Stinson, E. B., Oyer, P. E., Reitz, B. A., Shumway, N. E. 1994; 90 (5): II235-42

    Abstract

    Aortic dissection is one of the most lethal potential complications in patients with the Marfan syndrome.Among 360 patients undergoing operative treatment of aortic dissection between 1963 and 1992, 40 had the Marfan syndrome. There were 24 men and 16 women with a mean age of 35 +/- 9 years (+/- 1 SD; range, 15 to 54 years). These patients included 16 with acute type A, 2 with acute type B, 18 with chronic type A, and 4 with chronic type B aortic dissections. The aortic arch was involved in 29 cases. Preoperative complications included acute aortic valvular insufficiency in 13 patients, rupture into the pericardial space in 3, and loss of peripheral pulses in 9. The site of primary intimal tear was the ascending aorta in 25 patients, the aortic arch in 2, the descending aorta in 7, and not identified in 6. Operations included ascending aortic and aortic valvular replacement (with or without coronary artery reimplantation) in 22 patients, ascending aortic replacement alone in 5, and descending thoracic aortic replacement in 9. Four operative deaths (10 +/- 5% [+/- 70% confidence limits]) occurred in 3 acute patient-years and 1 chronic type A patient-years. Long-term follow-up (216 patient-years; range, 1 month to 22 years; mean, 5.4 years) revealed 15 late deaths, 7 from late aortic sequelae. The overall actuarial survival estimates were 71 +/- 8%, 54 +/- 10%, and 22 +/- 11% at 5, 10, and 15 years, respectively. Twenty late aortic operations were required in 14 patients.Despite satisfactory early results, the long-term survival of patients with the Marfan syndrome was suboptimal (albeit similar to those without the Marfan syndrome). Future progress will pivot on reducing the incidence of aortic dissection in these patients with medical therapy and/or earlier surgical intervention and enhanced postoperative serial imaging surveillance of the entire aorta.

    View details for PubMedID 7955259

  • THE USE OF ENDOVASCULAR TECHNIQUES FOR THE TREATMENT OF COMPLICATIONS OF AORTIC DISSECTION JOURNAL OF VASCULAR SURGERY Walker, P. J., Dake, M. D., Mitchell, R. S., Miller, D. C. 1993; 18 (6): 1042-1051

    Abstract

    Intravascular ultrasonography, balloon angioplasty, stent placement, and endovascular septal fenestration have been used in the evaluation and treatment of vascular complications of acute and chronic aortic dissection in five patients. There were three men and two women with an average age of 52 years (range 39 to 64 years). There were three chronic type A dissections, one acute type B, and one subacute type B dissection. Intravascular ultrasonography was used in all five cases. The three patients with chronic type A dissections underwent unilateral renal artery angioplasty (RA PTA) and stent placement; one patient with an acute type B dissection and associated fibromuscular dysplasia underwent bilateral RA PTA without stent placement. These procedures were performed to ameliorate severe hypertension. The final patient, with a subacute type B dissection, underwent iliac artery stenting to correct severe lower extremity ischemia. During a second intervention, this patient, who also had bowel ischemia and nonresolving acute renal failure, underwent balloon dilatation of a preexisting septal fenestration to augment visceral blood supply and bilateral RA PTA and stent placement in an effort to improve renal function. This patient eventually died of gut ischemia. After RA PTA and stent placement, one patient had a major intrarenal hemorrhage that required coil embolization and transfusion. In the four survivors, RA PTA and stent placement resulted in immediate improvement in blood pressure control. This response has been sustained during follow-up intervals ranging from 8 to 18 months (average 10 months). Intravascular ultrasonography can clearly demonstrate the pathologic anatomy associated with aortic dissection (even when angiography is ambiguous) and is essential for guiding therapeutic endovascular interventions. Further exploration of the efficacy of these endovascular techniques is warranted in this high-risk group of patients with aortic dissection who have appropriate clinical indications.

    View details for Web of Science ID A1993MM41200018

    View details for PubMedID 8264033

  • Management of patients with intramural hematoma of the thoracic aorta. Circulation Robbins, R. C., McManus, R. P., Mitchell, R. S., LATTER, D. R., Moon, M. R., Olinger, G. N., Miller, D. C. 1993; 88 (5): II1-10

    Abstract

    Intramural hematoma of the thoracic aorta (IMH) is a diagnosis of exclusion and represents spontaneous, localized hemorrhage into the wall of the thoracic aorta in the absence of bona fide aortic dissection, intimal tear, or penetrating atherosclerotic ulcer. This process may arise from primary vasa vasorum hemorrhage within the aortic media or rupture of an atherosclerotic plaque. The clinical presentation of patients with IMH mimics that of acute aortic dissection; moreover, considerable diagnostic confusion exists despite the use of many different imaging modalities. The optimal mode of management of patients with IMH (medical versus medical plus surgical) remains problematic because of the paucity of information available.Thirteen patients with IMH were managed at two medical centers between 1983 and 1992. Patients with IMH caused by giant penetrating atherosclerotic ulcers were specifically excluded. There were 8 women and 5 men (mean age, 70 years [range, 54 to 82 years]). The admitting clinical diagnosis was acute aortic dissection, and all patients had a history of hypertension. There was no evidence of aortic dissection or intimal disruption as assessed by computed tomographic (CT) scan (n = 11), aortography (n = 10), magnetic resonance imaging (MRI) scan (n = 9), transesophageal echocardiography (TEE) (n = 6), or intravascular ultrasound (n = 1). The diagnosis of IMH was established by exclusion. The descending thoracic aorta was involved in 10 cases and the ascending/arch in 3. Conservative medical management was attempted initially. All 3 patients with IMH involving the ascending aorta ultimately required operative intervention, and 2 individuals died; 2 of 10 patients with descending aortic involvement eventually underwent surgery. Average hospital stay was 11 days; the mean follow-up interval for discharged patients was 29 months.IMH is a distinct pathological entity, should not be confused with aortic dissection, and probably will be identified more frequently in the future. All patients with IMH should be monitored carefully and treated with aggressive antihypertensive therapy. Frequent serial assessment is necessary using TEE or MRI/CT scans. Based on this small experience, patients with ascending/arch IMH, ongoing pain, or IMH expansion should probably undergo early graft replacement. Patients with IMH involving the descending thoracic aorta who have no evidence of progression and become pain free can probably be treated conservatively but require antihypertensive therapy and serial aortic imaging surveillance indefinitely.

    View details for PubMedID 8222144

  • RANDOMIZED, PROSPECTIVE ASSESSMENT OF BIOPROSTHETIC VALVE DURABILITY - HANCOCK VERSUS CARPENTIER-EDWARDS VALVES CIRCULATION Sarris, G. E., Robbins, R. C., Miller, D. C., Mitchell, R. S., Moore, K. A., Stinson, E. B., Oyer, P. E., Reitz, B. A., Shumway, N. E. 1993; 88 (5): 55-64
  • Randomized, prospective assessment of bioprosthetic valve durability. Hancock versus Carpentier-Edwards valves. Circulation Sarris, G. E., Robbins, R. C., Miller, D. C., Mitchell, R. S., Moore, K. A., Stinson, E. B., Oyer, P. E., Reitz, B. A., Shumway, N. E. 1993; 88 (5): II55-64

    Abstract

    Although the major limitation of porcine valves is their finite durability, no controlled clinical data exist regarding the relative durability of the two porcine bioprostheses implanted most commonly today, the Carpentier-Edwards (C-E) and Medtronic Hancock I (H) valves.To assess this question, 174 patients undergoing aortic (AVR) or mitral (MVR) valve replacement with a bioprosthesis between March 1980 and March 1982 were randomized to receive either a C-E or a H valve. There were 102 AVRs (54 C-E and 48 H) and 74 MVRs (39 C-E and 35 H). For both the AVR and MVR cohorts, the average patient age was 58 +/- 14 years (+/- SD). The male/female ratio was 2.2:1 for AVR and 0.57:1 for MVR. Clinical follow-up was undertaken periodically; the most recent follow-up closing interval was July through October 1992, and current follow-up was 96% complete. Cumulative follow-up totaled 1369 patient-years (mean, 7.7 +/- 3.6 years; median, 9.1 years; maximum, 12.0 years). The main focus of this analysis was bioprosthetic durability, using the AATS/STS guidelines defining "Structural Valve Deterioration" (SVD). Multivariate analysis revealed that (younger) age was the only significant (P = .024) independent predictor of SVD. Valve manufacturer (C-E versus H) and valve site (aortic versus mitral) did not emerge as significant independent risk factors for SVD. Actuarial rates (Cutler-Ederer) expressed as percent free of SVD (+/- SEM) at 10 years (n = number of patients remaining at risk) were 71 +/- 7% and 59 +/- 9% for the C-E (n = 26) and H (n = 17) groups, respectively, for the AVR cohort; for the MVR cohort, these estimates were 60 +/- 10% (n = 12) and 72 +/- 10% (n = 11), respectively, but these differences were not statistically significant (P = NS, Lee-Desu).After 10 years, there was no statistically significant difference in durability or other valve-related complications between the H and C-E aortic or mitral valves. Based on current information, the choice of a porcine bioprosthesis should be based on factors other than durability, including ease of implantation, hemodynamic performance, and cost.

    View details for PubMedID 8222197

  • Composite aortic valve replacement and graft replacement of the ascending aorta plus coronary ostial reimplantation: how I do it. Seminars in thoracic and cardiovascular surgery Miller, D. C., Mitchell, R. S. 1993; 5 (1): 74-83

    View details for PubMedID 8425007

  • Successful percutaneous balloon catheter treatment of renal artery occlusion and anuria. Annals of vascular surgery Schneider, J. R., Wright, A., Mitchell, R. S. 1992; 6 (6): 533-536

    Abstract

    Progressive renal failure may be due to renal artery stenosis and occlusion. Gradual occlusion of the renal arteries may allow the development of collateral arterial supply sufficient to avoid dialysis. Even when dialysis is required, significant viable renal parenchyma may still be present to allow escape from dialysis following revascularization of one or both kidneys. The chance of success in such cases is thought to be better if the patient still produces a significant amount of urine. We report here a patient who was completely anuric for five days and in whom excellent renal function returned after balloon angioplasty of one of two occluded renal arteries.

    View details for PubMedID 1463668

  • DURABILITY OF PORCINE VALVES AT 15 YEARS IN A REPRESENTATIVE NORTH-AMERICAN PATIENT POPULATION JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Burdon, T. A., Miller, D. C., Oyer, P. E., Mitchell, R. S., Stinson, E. B., Starnes, V. A., Shumway, N. E. 1992; 103 (2): 238-252

    Abstract

    Isolated aortic (n = 857) or mitral (n = 793) valve replacement with a porcine bioprosthesis was performed in 1650 patients between 1971 and 1980. Follow-up (total = 12,012 patient-years) extended to more than 15 years and was 96% complete. Patient age ranged from 16 to 87 years; mean age was 59 +/- 11 years (+/- 1 standard deviation) for the aortic valve replacement cohort and 56 +/- 12 years for the mitral valve replacement cohort. The operative mortality rates were 5% +/- 1% (+/- 70% confidence limits) and 8% +/- 1%, respectively, for the aortic and mitral subgroups. Estimated freedom from structural valve deterioration (+/- 1 standard error of the mean) after 10 and 15 years was significantly higher for the aortic than for the mitral valve replacement subgroup (85% +/- 0.4% and 63% +/- 3% versus 78% +/- 2% and 45% +/- 3%, respectively, p = 0.001). Reoperation-free actuarial estimates were also significantly greater for the aortic valve replacement cohort: 83% +/- 2% and 57% +/- 3% versus 78% +/- 2% and 43% +/- 3% for mitral valve replacement at 10 and 15 years, respectively. The mortality rate for reoperative aortic valve replacement was 11% +/- 1%; it was 8% +/- 1% for reoperative mitral valve replacement. Importantly, the estimates of freedom from valve-related death (including sudden, unexplained deaths) were relatively high at 10 and 15 years: 78% +/- 2% and 69% +/- 3% in the aortic cohort and 74% +/- 2% and 63% +/- 3% in the mitral cohort (p = not significant). Excluding sudden, unexplained deaths, these estimates were 81% +/- 3% (aortic) and 73% +/- 4% (mitral) at 15 years. Thromboembolism-free rates were 84% +/- 3% (aortic) and 78% +/- 6% (mitral) at 15 years, and freedom from anticoagulant-related hemorrhage was 96% +/- 1% and 89% +/- 2%, respectively. At the time of current follow-up, 13% of patients having aortic valve replacement and 50% of patients having mitral valve replacement were receiving warfarin sodium. The hazard functions for thromboembolism and prosthetic valve endocarditis were constant and remained less than 1%/pt-yr over the entire follow-up period.(ABSTRACT TRUNCATED AT 400 WORDS)

    View details for Web of Science ID A1992HD22500008

    View details for PubMedID 1735989

  • TREATMENT OF PATIENTS WITH AORTIC DISSECTION PRESENTING WITH PERIPHERAL VASCULAR COMPLICATIONS ANNALS OF SURGERY Fann, J. I., Sarris, G. E., Mitchell, R. S., Shumway, N. E., Stinson, E. B., Oyer, P. E., Miller, D. C. 1990; 212 (6): 705-713

    Abstract

    The incidence of peripheral vascular complications in 272 patients with aortic dissection during a 25-year span was determined, as was outcome after a uniform, aggressive surgical approach directed at repair of the thoracic aorta. One hundred twenty-eight patients (47%) presented with acute type A dissection, 70 (26%) with chronic type A, 40 (15%) with acute type B, and 34 (12%) with chronic type B dissections. Eighty-five patients (31%) sustained one or more peripheral vascular complications: Seven (3%) had a stroke, nine (3%) had paraplegia, 66 (24%) sustained loss of a peripheral pulse, 22 (8%) had impaired renal perfusion, and 14 patients (5%) had compromised visceral perfusion. Following repair of the thoracic aorta, local peripheral vascular procedures were unnecessary in 92% of patients who presented with absence of a peripheral pulse. The operative mortality rate for all patients was 25% +/- 3% (68 of 272 patients). For the subsets of individuals with paraplegia, loss of renal perfusion, and compromised visceral perfusion, the operative mortality rates (+/- 70% confidence limits) were high: 44% +/- 17% (4 of 9 patients), 50% +/- 11% (11 of 22 patients), and 43% +/- 14% (6 of 14 patients), respectively. The mortality rates were lower for patients presenting with stroke (14% +/- 14% [1 of 7 patients]) or loss of peripheral pulse (27% +/- 6% [18 of 66 patients]). Multivariate analysis revealed that impaired renal perfusion was the only peripheral vascular complication that was a significant independent predictor of increased operative mortality risk (p = 0.024); earlier surgical referral (replacement of the appropriate section of the thoracic aorta) or more expeditious diagnosis followed by surgical renal artery revascularization after a thoracic procedure may represent the only way to improve outcome in this high-risk patient subset. Early, aggressive thoracic aortic repair (followed by aortic fenestration and/or abdominal exploration with or without direct visceral or renal vascular reconstruction when necessary) can save some patients with compromised visceral perfusion; however, once visceral infarction develops the prognosis is also poor. Increased awareness of these devastating complications of aortic dissection and the availability of better diagnostic tools today may improve the survival rate for these patients in the future. The initial surgical procedure should include repair of the thoracic aorta in most patients.

    View details for Web of Science ID A1990EN33200009

    View details for PubMedID 2256762

  • Surgical management of acute aortic dissection complicated by stroke. Circulation Fann, J. I., Sarris, G. E., Miller, D. C., Mitchell, R. S., Oyer, P. E., Stinson, E. B., Shumway, N. E. 1989; 80 (3): I257-63

    Abstract

    Although patients with acute type A aortic dissection are best managed by emergency surgical intervention, preoperative stroke is known to be an independent predictor of late mortality and is considered by some to be a contraindication to operation because of the risk of precipitating hemorrhagic cerebral infarction and poor long-term outcome. In a series of 272 consecutive, unselected patients with aortic dissection undergoing surgical treatment during a 25-year span (1963-1987), 128 (47 +/- 3% [+/- 70% confidence level (CL)]) had an acute type A dissection. A total of seven patients with acute type A dissection (2.6 +/- 1% of all patients, 5.5 +/- 2% of the acute type A cohort) developed a new stroke preoperatively. Thirteen (4.8 +/- 1%) patients had a diminished or absent carotid pulse, only four (31 +/- 13%) of whom sustained a stroke. One patient died in the immediate postoperative period due to severe brain injury, yielding an operative mortality rate of 14 +/- 14%. Two patients had persistent neurological deficits and died within 4 months of operation; the actuarial survival estimate at 1 year was 57 +/- 19% (mean +/- SEM). One patient recovered function of one upper extremity (preoperative left hemiparesis compounded by paraplegia) but died 6 years later. The remaining three long-term survivors (43 +/- 19%) had major resolution of their neurological deficits and are clinically well 2-8 years postoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)

    View details for PubMedID 2766534

  • SURGICAL-MANAGEMENT OF ACUTE AORTIC DISSECTION COMPLICATED BY STROKE CIRCULATION Fann, J. I., Sarris, G. E., Miller, D. C., Mitchell, R. S., Oyer, P. E., Stinson, E. B., Shumway, N. E. 1989; 80 (3): 257-263
  • INHIBITION OF ACCELERATED CARDIAC ALLOGRAFT ARTERIOSCLEROSIS BY FISH OIL JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Sarris, G. E., Mitchell, R. S., Billingham, M. E., Glasson, J. R., CAHILL, P. D., Miller, D. C. 1989; 97 (6): 841-855

    Abstract

    Accelerated coronary arteriosclerosis remains the most important factor limiting long-term survival of heart transplant recipients, and dietary fish oil supplementation with omega-3 polyunsaturated fatty acids has been suggested to have a protective effect against coronary disease in epidemiologic studies and to inhibit arteriosclerosis in animal experiments. Therefore we tested the hypothesis that fish oil administration inhibits the development of allograft coronary arteriosclerosis by using a heterotopic heart transplant model. Three groups of Lewis rats (n = 10 each) received heterotopic heart transplants from Brown-Norway donors and were treated with cyclosporine intraperitoneally on a tapering schedule. Group 1 received fish oil daily by gavage (2 ml/kg/day; Emulsified Super MaxEpa, Twin Labs, Ronkonkona, N.Y.). Group 2 received an equal amount of safflower oil, as well as aspirin (1 mg/kg/day) and dipyridamole (3 mg/kg/day). Group 3 received safflower oil only. All rats were put to death 110 days later, at which time there was no statistically significant difference in graft function as assessed by palpation (scale 0 to 4, mean = 3.7 +/- 0.5 [+/- standard deviation]; analysis of variance: p = 0.72) or in microscopic grade of rejection (scale, 0 = none to 3 = severe, mean 2.1 +/- 0.6; analysis of variance: p = 0.68) between any of the groups. The coronary arteries were histologically scored for the degree of arteriosclerosis (scale, 0 = normal to 3 = occluded), and a mean grade of coronary disease was calculated for each heart. The fish oil-treated group had significantly less severe allograft coronary arteriosclerosis (analysis of variance: p = 0.005) than did groups 2 and 3 (mean grade 0.23 +/- 0.22 versus 1.04 +/- 0.75 and 0.96 +/- 0.55 (p less than 0.05, Scheffe F test), whereas groups 2 and 3 had similar degrees of coronary disease (p = no significant difference). These data demonstrate that fish oil supplementation inhibited accelerated coronary arteriosclerosis in this cyclosporine-treated heart allograft rat model, whereas antiplatelet agents in these doses were ineffective. Although the mechanism of this protective effect remains incompletely understood, it does not appear to involve enhanced immunosuppression. Fish oil and specific omega-3 polyunsaturated fatty acids should be further investigated as potentially useful agents to ameliorate accelerated allograft coronary arteriosclerosis in other animal species and perhaps eventually in man.

    View details for Web of Science ID A1989AA70000005

    View details for PubMedID 2657223

  • REGIONAL VARIABILITY OF PROSTACYCLIN BIOSYNTHESIS ARTERIOSCLEROSIS Fann, J. I., CAHILL, P. D., Mitchell, R. S., Miller, D. C. 1989; 9 (3): 368-373

    Abstract

    To investigate the regional variability in arterial and venous endothelial prostacyclin (PGI2) biosynthesis, we obtained 1-cm segments of carotid arteries, external jugular veins, femoral arteries and veins, iliac arteries and veins, inferior venae cavae (IVC), and aortas from 17 dogs. Vessel luminal PGI2 production was measured in the basal state by radioimmunoassay of 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha). A total of 90 arterial specimens (57, 19, and 14 segments, respectively, of femoral/carotid arteries, iliac arteries, and aorta) and 41 venous specimens (15, 10, and 16 segments, respectively, of femoral/jugular veins, iliac veins, and IVC) were analyzed. Overall, arterial endothelial 6-keto-PGF1 alpha was higher than venous (8.1 +/- 0.5 ng/ml vs. 4.9 +/- 0.7 ng/ml, p less than 0.0004); 6-keto-PGF1 alpha levels were greater in the arteries than in their corresponding veins [femoral/carotid arteries (6.3 +/- 0.4 ng/ml) vs. femoral/jugular vein (2.1 +/- 0.4 ng/ml), p less than 0.0002; iliac arteries (9.3 +/- 1.0 ng/ml) vs. iliac veins (4.8 +/- 0.9 ng/ml), p less than 0.005; aorta (14.0 +/- 1.6 ng/ml) vs. IVC (7.5 +/- 1.4 ng/ml), p less than 0.006].(ABSTRACT TRUNCATED AT 250 WORDS)

    View details for Web of Science ID A1989U695400012

    View details for PubMedID 2655571

  • THE VASCULAR WAR OF 1988 JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION Wexler, L., Ginsburg, R., Mitchell, R. S., MEHIGAN, J. T. 1989; 261 (3): 418-419

    View details for Web of Science ID A1989R767700031

    View details for PubMedID 2521257

  • EFFECTS OF ASPIRIN, DIPYRIDAMOLE, AND COD LIVER OIL ON ACCELERATED MYOINTIMAL PROLIFERATION IN CANINE VENOARTERIAL ALLOGRAFTS ANNALS OF SURGERY DeCampli, W. M., Kosek, J. C., Mitchell, R. S., Handen, C. E., Miller, D. C. 1988; 208 (6): 746-754

    Abstract

    The effects of the administration of aspirin (ASA), dipyridamole (DPM), and cod liver oil (CLO) on graft patency rate and degree of intimal hyperplasia were investigated in a canine, hypercholesterolemic veno-arterial allograft model in an attempt to modify this immunologically mediated vascular injury. The drug regimens were ASA 1 mg/kg/day, DPM 10 mg/kg/day, combined ASA and DPM (ASA + DPM), and CLO (1.8 g/day eicosapentanoic acid [EPA] and 1.2 g/day docosahexanoic acid [DHA]), and control. The early angiographic patency rate (1-3 weeks) was 81% +/- 10% (+/- 70% confidence limits); the 90-day overall patency rate was 60% +/- 4% (87/144), with no statistically significant differences among the groups (range 46 +/- 10-71 +/- 9%). Qualitatively, there was no difference in luminal thrombus, intimal hemorrhage, or lesion eccentricity. Considering the relatively short time of graft implantation, an extensive amount of microscopic disease was observed; quantitatively, the mean intimal thickness was 515 +/- 17 microgram overall but was not statistically different between the groups. The fraction of potential lumenal area occupied by intimal thickening was 0.37 +/- 0.01 but again did not differ significantly between the groups. These doses of ASA, DPM, ASA + DPM, and CLO did not alter graft occlusion or retard the marked degree of subintimal myointimal cell hyperplasia that was generated in this hypercholesterolemic canine veno-arterial allograft preparation. Possible explanations for these negative findings include inadequate dosage or form of omega-3 fatty acids and the antiplatelet drugs administered, excessive variability in graft response due to uncharacterized immunologic histocompatibility, and the possible influence of non-platelet-mediated mechanisms. Nevertheless, this preparation is attractive as a reproducible model of accelerated (immunologically mediated) experimental arteriosclerosis.

    View details for Web of Science ID A1988R209600013

    View details for PubMedID 3196097

  • INHIBITION OF VEIN GRAFT INTIMAL THICKENING BY EICOSAPENTANOIC ACID - REDUCED THROMBOXANE PRODUCTION WITHOUT CHANGE IN LIPOPROTEIN LEVELS OR LOW-DENSITY LIPOPROTEIN RECEPTOR DENSITY JOURNAL OF VASCULAR SURGERY CAHILL, P. D., Sarris, G. E., Cooper, A. D., Wood, P. D., Kosek, J. C., Mitchell, R. S., Miller, D. C. 1988; 7 (1): 108-118

    Abstract

    Marine lipids containing omega-3 fatty acids (chiefly, eicosapentanoic acid [EPA] and docosahexanoic acid [DHA]) may inhibit the development of atherosclerotic vascular disease, but the mechanisms responsible for this putative beneficial effect are unknown. We investigated the effects of EPA and DHA in a canine model of accelerated vein graft arteriosclerosis during a 3-month period. Twenty-five dogs were divided into three dietary groups: group I (control), group II (2.5% cholesterol), and group III (2.5% cholesterol plus 2 gm EPA/day [as MaxEPA]). The effects of EPA on vein graft intimal thickening, platelet and vascular prostaglandin metabolism, lipid and lipoprotein receptor metabolism, and hematologic parameters were assessed. Cholesterol feeding caused a significant 54% increase in graft intimal thickness compared with control animals (124.9 +/- 50.4 vs 81.2 +/- 32.4 micron; p = 0.013), which was prevented by supplementation with EPA in group III (56.9 +/- 30.0 micron; p = 0.001 vs group II). Intimal thickness in group III was not significantly different from that of control. EPA supplementation was also associated with a 38% decline in serum thromboxane levels from 457.0 +/- 129.3 pg/0.1 ml in group II to 283.5 +/- 96.9 pg/0.1 ml in group III (p = 0.007). The alterations in lipoprotein metabolism associated with cholesterol feeding were not affected by EPA: in both groups II and III, serum cholesterol and high-density lipoproteins and liver cholesterol content were elevated and hepatic low-density lipoproteins (LDL) receptor content was reduced. There were no differences between the three groups in terms of vein graft or native vessel prostacyclin production, hematocrit, platelet count, or coagulation parameters. In this canine model, dietary supplementation with marine omega-3 fatty acids reduced the extent and magnitude of accelerated vein graft intimal thickening induced by hypercholesterolemia; moreover, this beneficial effect was associated with lower serum thromboxane production and appeared to be independent of alterations in lipoprotein metabolism or LDL receptor density.

    View details for Web of Science ID A1988L687000013

    View details for PubMedID 3336117

  • PHARMACOLOGICAL, HEMATOLOGICAL, AND PHYSIOLOGICAL-EFFECTS OF A NEW THROMBOXANE SYNTHETASE INHIBITOR (CGS-13080) DURING CARDIOPULMONARY BYPASS IN DOGS ANNALS OF THORACIC SURGERY DeCampli, W. M., Goodwin, D., Kosek, J. C., Handen, C. E., Mitchell, R. S., Miller, D. C. 1986; 42 (6): 690-696

    Abstract

    The hematological and pharmacological effects of a new thromboxane synthetase inhibitor, CGS-13080 (imidazo[1,5-alpha]pyridine-5-hexanoic acid), were investigated during cardiopulmonary bypass in a blinded, randomized manner in dogs. Compared with placebo, CGS-13080 suppressed thrombin-stimulated platelet thromboxane B2 production by 90% during cardiopulmonary bypass (p less than .001), an effect that persisted for two hours after stopping the infusion. In the CGS-13080-treated group, plasma 6-keto-prostaglandin F1 alpha levels significantly increased over time (p less than .03) and were somewhat higher when compared with those in the placebo-treated group. This observation suggests that an "endoperoxide shunt" may have occurred. In the control group, an inverse correlation between platelet count and level of thromboxane B2 per platelet following in vitro thrombin stimulation (r = .5, p less than .001) was apparent, but there was no correlation between these two variables (r = .18, p less than .10) in the CGS-13080-treated group. No adverse hemodynamic or other effects attributable to CGS-13080 occurred during or immediately following cardiopulmonary bypass. These results suggest that CGS-13080 is an effective inhibitor of thromboxane B2 production during cardiopulmonary bypass in dogs and has no adverse physiological effects.

    View details for Web of Science ID A1986F174300017

    View details for PubMedID 3789860

  • COMPREHENSIVE ASSESSMENT OF THE SAFETY, DURABILITY, CLINICAL-PERFORMANCE, AND HEALING CHARACTERISTICS OF A DOUBLE VELOUR KNITTED DACRON ARTERIAL PROSTHESIS VASCULAR SURGERY Mitchell, R. S., Miller, D. C., Billingham, M. E., MEHIGAN, J. T., Olcott, C., Stinson, E. B. 1980; 14 (3): 197-212

Conference Proceedings


  • Endovascular stent-graft repair of descending thoracic aortic penetrating atherosclerotic ulcers: Mid-term results Demers, P., Miller, D. C., Mitchell, R. S., Kee, S. T., Chagonjian, L., Dake, M. D. ELSEVIER SCIENCE INC. 2003: 236A-236A
  • First International Summit on Thoracic Aortic Endografting: roundtable on thoracic aortic dissection as an indication for endografting. Mitchell, R. S., Ishimaru, S., Ehrlich, M. P., Iwase, T., Lauterjung, L., Shimono, T., Fattori, R., Yutani, C. 2002: II98-105

    View details for PubMedID 12166849

  • Does hypothermic circulatory arrest (PHCA) improve survival in patients with acute type A aortic dissection? Lai, D. T., Robbins, R. C., Mitchell, R. S., Moore, K. A., Oyer, P. E., Shumway, N. E., Reitz, B. A., Miller, D. C. LIPPINCOTT WILLIAMS & WILKINS. 2001: 524-524
  • Percutaneous balloon fenestration and stenting for life-threatening ischemic complications in patients with acute aortic dissection Slonim, S. M., Miller, D. C., Mitchell, R. S., Semba, C. P., Razavi, M. K., Dake, M. D. MOSBY-ELSEVIER. 1999: 1118-1126

    Abstract

    Acute aortic dissection frequently causes life-threatening ischemia of end-organs, historically associated with mortality exceeding 60%. Reperfusion with the use of interventional radiologic methods has evolved as a promising treatment. We report results of our initial 6 years of experience with percutaneous balloon fenestration of the intimal flap and endovascular stenting.Forty patients (32 male and 8 female) with a median age of 53 years (range 16-86 years) underwent percutaneous treatment for peripheral ischemic complications of 10 type A and 30 type B acute aortic dissections since 1991. Twenty patients had ischemia of multiple organ systems. Thirty patients had renal, 22 had leg, 18 had mesenteric, and 1 had arm ischemia.Fourteen patients were treated with stenting of either the true or false lumen combined with balloon fenestration of the intimal flap, 24 with stenting alone, and 2 with fenestration alone. Successful revascularization was achieved in 93% +/- 4% (+/-70% confidence levels) of patients (37/40). Nine patients had procedure-related complications. The 30-day mortality rate was 25% +/- 7% (10/40), often related to irreversible ischemia of intra-abdominal organs that was present before the procedure. Of the remaining 30 patients, 5 have died and the remaining 25 continue to have relief of ischemic symptoms at a mean follow-up of 29 months.Percutaneous balloon fenestration of the intimal flap and endovascular stenting is an effective treatment for life-threatening ischemic complications of acute aortic dissection.

    View details for Web of Science ID 000080866800010

    View details for PubMedID 10343260

  • Thoracic aortic aneurysm repair with an endovascular stent graft: The "first generation" Mitchell, R. S., Miller, D. C., Dake, M. D., Semba, C. P., Moore, K. A., Sakai, T. ELSEVIER SCIENCE INC. 1999: 1971-1974

    Abstract

    The feasibility and efficacy trial of an endovascular stent-grafting system for the treatment of aneurysms of the descending thoracic aorta was investigated.After Institutional Review Board approval, 103 patients (mean age 69 years) underwent stent graft repair of a descending thoracic aortic aneurysm between July 1992 and November 1997. The stent graft was fabricated using self-expanding "Z" stents covered by a woven Dacron tube graft. Follow-up, which averaged 22 months, was 100% complete. Simultaneous open abdominal aortic aneurysm repair was performed in 19 patients.Complete aneurysm thrombosis was achieved in 86 patients (83%). Early mortality, defined as a death during the same hospitalization or in less than 30 days, was 9 +/- 3%, and was significantly associated with preoperative cerebrovascular accident (CVA) or myocardial infarction. Major perioperative morbidity occurred in 31 patients, and included paraplegia in 3, CVA in 7, and respiratory insufficiency in 12 patients each. Actuarial survival was 81 +/- 4% at 1 year, and 73 +/- 5% at 2 years. Treatment failure (including all late, sudden, unexplained deaths) occurred in 38 patients, and only 53 +/- 10% of patients were free of treatment failure at 3.7 years. Five patients required late operative therapy for endoleaks associated with aneurysm enlargement.Satisfactory results were achieved using this "first-generation" homemade stent graft device. Mortality and morbidity occurred frequently, but may have been associated with the high-risk character of this patient population. Medium-term results were acceptable, but continued aortic enlargement, with the late development of endoleaks, is a significant concern. Second-generation devices with commercial development, coupled with this initial experience, should allow improved clinical results in the future. Longer term follow-up is still necessary to fully define the efficacy of this endovascular approach.

    View details for Web of Science ID 000081137800122

    View details for PubMedID 10391350

  • Endografts for the treatment of descending thoracic aortic aneurysm: Results of the first 150 procedures Dake, M., Semba, C., Kee, S., Razavi, M., Slonim, S., Samuels, S., Sze, D., Mitchell, R., Miller, D. INT SOC ENDOVASCULAR SPECIALIST. 1999: 189-189
  • Endovascular stent-graft placement to obliterate the entry tear: A new treatment for acute aortic dissection Dake, M. D., Kato, N., Slonim, S. M., Razavi, M. K., Semba, C. P., Kee, S. T., Sze, D. Y., Samuels, S. L., Mitchell, R. S., Miller, D. C. LIPPINCOTT WILLIAMS & WILKINS. 1998: 67-67
  • Surgical treatment of endocarditis: Is there a role for mechanical prostheses? Moon, M. R., Miller, D. C., Stinson, E. B., Mitchell, R. S., Oyer, P. E., Robbins, R. C., Shumway, N. E., Reitz, B. A. LIPPINCOTT WILLIAMS & WILKINS. 1997: 2409-2409
  • Simultaneous abdominal aortic replacement and thoracic stent-graft placement for multilevel aortic disease Moon, M. R., Mitchell, R. S., Dake, M. D., Zarins, C. K., Fann, J. I., Miller, D. C. MOSBY-YEAR BOOK INC. 1997: 332-340

    Abstract

    Patients with aneurysmal disease involving both the descending thoracic and abdominal aorta have historically required simultaneous or sequential conventional operations, but the morbidity rate is high with either approach in these patients, who often exhibit coexisting cardiopulmonary disease. Transluminally placed endovascular grafts have recently been developed for repair of aortic aneurysms, and we have implemented these techniques to eliminate the need for a thoracotomy in patients with multilevel aortic disease.Since January 1994, 18 patients have undergone conventional abdominal aortic replacement with endovascular stent-graft placement into the descending thoracic aorta under fluoroscopic guidance through a 10 mm Dacron side limb off the abdominal graft. Abdominal aortic replacement required a tube graft in eight patients and bifurcated grafts in 10 patients. Thoracic stent-grafts (custom fabricated, woven Dacron covered, self-expandable stents) averaged 12.2 +/- 4.2 cm (mean +/- SD) in length.One patient died, resulting in a hospital mortality rate of 6%. No patients required further surgical intervention to treat their aortic disease. Seventeen patients (94%) are currently well 14 +/- 8 months after surgery (range, 3 to 29 months) with completely excluded thoracic aortic disease, no stent migration, and no change in stent configuration documented by serial radiologic examinations.Simultaneous abdominal aortic replacement and deployment of a thoracic stent-graft can safely exclude multilevel aortic aneurysmal disease and may be a valuable treatment option for these otherwise high-risk patients.

    View details for Web of Science ID A1997WL46300024

    View details for PubMedID 9052568

  • Twenty-year clinical experience with porcine bioprostheses Fann, J. I., Miller, D. C., Moore, K. A., Mitchell, R. S., Oyer, P. E., Stinson, E. B., Robbins, R. C., Reitz, B. A., Shumway, N. E. ELSEVIER SCIENCE INC. 1996: 1301-1311

    Abstract

    For the past 25 years, porcine valves have been the most widely implanted bioprosthesis, thereby becoming the standard for comparison with newer bioprosthetic valves.We retrospectively analyzed 2,879 patients who underwent aortic (AVR; n = 1,594) or mitral (MVR; n = 1,285) valve replacement between 1971 and 1990. Follow-up was 97% complete and extended to 20 years (total, 17,976 patient-years). Patient age ranged from 16 to 94 years; mean age in patients who underwent AVR was 60 +/- 15 (+/- standard deviation) years; that for patients who underwent MVR was 58 +/- 13 years.The operative mortality rates were 7% +/- 1% (70% confidence limits) for AVR and 10% +/- 1% for MVR. Actuarial estimates of freedom from structural valve deterioration at 10 and 15 years were 78% +/- 2% (SE) and 49% +/- 4%, respectively, for the AVR subgroup; and 69% +/- 2% and 32% +/- 4%, respectively, for the MVR subgroup (AVR > MVR; p < 0.05). Estimates of freedom from reoperation at 10 and 15 years were 76% +/- 2% and 53% +/- 4%, respectively, for the AVR subgroup and 70% +/- 2% and 33% +/- 4%, respectively, for the MVR subgroup (AVR > MVR; p < 0.05). Estimates of freedom from thromboembolism at 10 and 15 years were 92% +/- 1% and 87% +/- 2%, respectively, for the AVR subgroup and 86% +/- 1% and 77% +/- 3%, respectively, for the MVR subgroup (AVR > MVR; p < 0.05). Estimates of freedom from anticoagulant-related hemorrhage at 10 and 15 years were both 96% +/- 1% for the AVR subgroup and 93% +/- 1% and 90% +/- 2%, respectively, for the MVR subgroup (AVR > MVR; p < 0.05). Estimates of freedom from valve-related mortality at 10 and 15 years were 86% +/- 1% and 78% +/- 3%, respectively, for the AVR subgroup and 84% +/- 2% and 70% +/- 4%, respectively, for the MVR subgroup (p = not significant). Multivariate analysis (Cox model) showed younger age, later year of operation, and valve site (MVR > AVR) to be significant risk factors for structural valve deterioration. Younger age, later year of operation, valve site (MVR > AVR), and renal insufficiency were the significant, independent risk factors for reoperation. Multivariate analysis revealed that higher New York Heart Association functional class, longer cardiopulmonary bypass time, congestive heart failure, renal insufficiency, and longer cross-clamp time were significant risk factors for valve-related mortality. Valve manufacturer did not emerge as a factor in any analysis.These long-term results with porcine bioprostheses were satisfactory, particularly in older patients and those undergoing AVR. As expected, younger age was a significant risk factor for structural valve deterioration and reoperation in both groups. Surprisingly, the durability of porcine bioprosthetic valves has not improved over time, which possibly can be attributed to more enhanced postoperative surveillance and earlier reintervention. These first-generation Hancock and Carpentier-Edwards porcine bioprostheses achieved similar long-term performance.

    View details for Web of Science ID A1996VQ16700014

    View details for PubMedID 8893561

  • Composite versus separate aortic valve and ascending aortic replacement - 30 year experience Yun, K. L., Fann, J. I., Miller, D. C., Mitchell, R. S., Robbins, R. C., Oyer, P. E., Stinson, E. B., Reitz, B. A., Shumway, N. E. LIPPINCOTT WILLIAMS & WILKINS. 1996: 1017-1017
  • True lumen obliteration in complicated aortic dissection: Endovascular treatment Slonim, S. M., NYMAN, U. R., Semba, C. P., Miller, D. C., Mitchell, R. S., Dake, M. D. RADIOLOGICAL SOC NORTH AMER. 1996: 161-166

    Abstract

    To evaluate endovascular treatment of ischemic complications caused by true lumen obliteration in aortic dissection.Endovascular techniques were used to treat true lumen obliteration in 11 patients with complicated aortic dissection. In all cases, the true lumen was compressed to a paper-thin sliver by the expanded false lumen. Two patients had Stanford type A (chronic) and nine had type B (six acute, three chronic) dissections. Obliteration of the true lumen was associated with branch vessel ischemia that included renal (n = 7), mesenteric (n = 6), and lower-extremity (n = 6) arterial compromise. Two patients were treated with aortic stents, four with balloon fenestration of the intimal flap, and three with both stent placement and fenestration. In two patients, ischemic complications caused by true lumen obliteration could not be treated with endovascular techniques.Revascularization was technically successful with relief of clinical symptoms in nine patients. Revascularization was unsuccessful in one patient in whom surgical revascularization of the superior mesenteric artery was necessary and in one in whom hypertension was managed medically. One patient developed thrombosis of a renal artery in which a stent had been placed. The 30-day mortality rate was 9%, and the mean follow-up was 10.1 months (range, 2 weeks to 39 months).True lumen obliteration can be safely and effectively treated with endovascular stent placement and balloon fenestration.

    View details for Web of Science ID A1996VJ11400034

    View details for PubMedID 8816538

  • Port-access coronary artery bypass with cardioplegic arrest: Acute and chronic canine studies Stevens, J. H., Burdon, T. A., Siegel, L. C., Peters, W. S., Pompili, M. F., STGOAR, F. G., Berry, G. J., Ribakove, G. H., Vierra, M. A., Mitchell, R. S., Toomasian, J. M., Reitz, B. A. ELSEVIER SCIENCE INC. 1996: 435-440

    Abstract

    Our goal is to perform minimally invasive coronary artery bypass grafting without sacrificing the benefits of myocardial protection with cardioplegia.Twenty-three dogs underwent acute studies and 4 dogs underwent survival studies. The left internal mammary artery was taken down using a thoracoscope. Cardiopulmonary bypass was conducted via femoral cannulas and using an endovascular balloon catheter for ascending aortic occlusion, root venting, and delivery of antegrade blood cardioplegia. Pulmonary artery venting was achieved with a jugular vein catheter. An internal mammary artery-to-coronary artery anastomosis was performed using a microscope through a 10 mm port.All animals were weaned from cardiopulmonary bypass in sinus rhythm without inotropes. Cardiopulmonary bypass duration was 104 +/- 28 minutes and aortic clamp duration was 61 +/- 22 minutes. Cardiac output and pulmonary artery occlusion pressure were unchanged. The internal mammary artery was anastomosed to the left anterior descending artery (25) or the first diagonal (2) with patency shown in 25 of 27. One dog in the survival study had a very short internal mammary artery pedicle under tension and was euthanized for excessive postoperative hemorrhage. Three weeks postoperatively the remaining dogs had angiographically patent anastomoses, normal transthoracic echocardiograms, and histologically normal healing and patent grafts.Endovascular cardiopulmonary bypass using a balloon catheter is effective in arresting and protecting the heart to allow thoracoscopic internal mammary artery-to-coronary artery anastomosis.

    View details for Web of Science ID A1996VA28700026

    View details for PubMedID 8694602

  • Endovascular stent-graft repair of thoracic aortic aneurysms Mitchell, R. S., Dake, M. D., Semba, C. P., Fogarty, T. J., Zarins, C. K., Liddell, R. P., Miller, D. C. MOSBY-YEAR BOOK INC. 1996: 1054-1060

    Abstract

    Conventional repair of aneurysms of the descending thoracic aorta entails thoracotomy and graft interposition. For elderly patients and those with previous operations, obesity, respiratory insufficiency, or other comorbidities, such a procedure entails significant mortality and morbidity. Transluminal stent-graft placement offers an alternative approach with potentially less morbidity and quicker recovery; however, the effectiveness and durability of stent-grafts remain uncertain.Since July 1992, thoracic aortic stent-grafts have been placed in 44 patients with a variety of pathologic conditions. Each graft was individually constructed from self- expanding, stainless-steel Z stents covered with a woven Dacron polyester fabric graft. Craft dimensions were determined from spiral computed tomographic scans. All implants were performed in the operating theater under fluoroscopic and transesophageal echocardiographic guidance. Follow-up was by computed tomography and contrast angiography in all cases. PATIENT DATA: There were 36 men and 8 women. Mean age was 66 years (range 35 to 88 years). Mean aneurysmal diameter was 6.3 cm (range 4.0 to 9.4 cm). Etiologies included 23 degenerative aneurysms, four posttraumatic aneurysms, four pseudoaneurysms, and one chronic aortic dissection.There were three early deaths (<30 days) and two late deaths. One early death resulted from graft failure. There were two instances of paraparesis or paraplegia, with one associated early death. A single stent was deployed in 27 patients, two stents were required in 14 patients, and three stents were required in three patients. In 23 patients, vascular access was attained through the femoral artery; abdominal aortic access, either native or graft, was necessary in the remaining 21 patients. Twelve grafts were placed in conjunction with open abdominal aortic surgical procedures. Mean follow-up (98% complete) was 12.6 months (range 1 to 34 months). One late death occurred from aneurysmal expansion and rupture in a patient with a persistent midgraft leak. The second late death may have resulted from aneurysmal rupture. Immediate thrombosis was achieved in 36 patients, and late thrombosis was achieved in three others. Failure to achieve complete aneurysmal thrombosis occurred in five patients, however, and one individual (previously noted) died of aneurysmal expansion and rupture; the remaining four are being carefully monitored. Only one patient has required conversion of the stent to an open procedure; a contained rupture of the false lumen of a chronic dissection eventually necessitated total descending thoracic aortic exclusion.These early results support the hypothesis that endovascular stent-graft placement may be a safe and durable treatment for selected patients with aneurysmal disease of the descending thoracic aorta. Large introducer size (26F outer diameter) and relatively limited angulation capability, as well as imprecise deployment techniques, currently limit its applicability. Distal embolization and stent migration have not been observed. Failure to achieve complete aneurysmal thrombosis may allow continued aneurysmal expansion and rupture. Further follow-up is clearly necessary to evaluate the true long-term effectiveness of this procedure.

    View details for Web of Science ID A1996UK88400026

    View details for PubMedID 8622303

  • Anesthetic considerations for port-access cardiac surgery Siegel, L. C., Peters, W. S., STGOAR, F. G., Stevens, J. H., Pompili, M. F., Howard, S. K., Burdon, T. A., Ribakove, G. H., Mitchell, R. S. LIPPINCOTT WILLIAMS & WILKINS. 1996: SCA79-SCA79
  • Aortic dissection: Percutaneous management of ischemic complications with endovascular stents and balloon fenestration Slonim, S. M., Nyman, U., Semba, C. P., Miller, D. C., Mitchell, R. S., Dake, M. D. MOSBY-ELSEVIER. 1996: 241-251

    Abstract

    The purpose of this study was to evaluate endovascular stenting (EVS) and balloon fenestration (BF) of intimal flaps for the management of lower extremity, renal, and visceral ischemia in acute or chronic aortic dissection.Twenty-two patients (16 male, 6 female) with a median age of 53 years (range 35 to 77 years) underwent percutaneous treatment for peripheral ischemic complications of 12 type A (five acute, seven chronic) and 10 type B (nine acute, one chronic) aortic dissections.Ten patients had leg ischemia, 13 had renal ischemia, and 6 had visceral ischemia. Sixteen patients were treated with EVS including 11 with renal, 6 with lower extremity, 2 with superior mesenteric artery, and 2 with aortic stents. Three patients had BF of the intimal flap, and three had BF in combination with EVS. Revascularization with clinical success was achieved in all 22 patients. Two patients died 3 days and 13.4 months after the procedure was performed, respectively. Of the remaining 20 patients, 1 is lost to follow-up, and 19 have persistent relief of clinical symptoms. Mean follow-up time is 13.7 months (range 1.1 to 46.5 months). One case was complicated by guidewire-induced perinephric hematoma.EVS and BF provide a safe and effective percutaneous method for managing peripheral ischemic complications of aortic dissection.

    View details for Web of Science ID A1996TW97700012

    View details for PubMedID 8637101

  • TRUE LUMEN OBLITERATION IN COMPLICATED AORTIC DISSECTION - ENDOVASCULAR MANAGEMENT Slonim, S. M., Dake, M. D., Semba, C. P., Razavi, M. K., NYMAN, U. R., Miller, D. C., Mitchell, R. S. LIPPINCOTT WILLIAMS & WILKINS. 1995: 602-602
  • DURABILITY OF THE HANCOCK-MO BIOPROSTHESIS COMPARED WITH STANDARD AORTIC-VALVE BIOPROSTHESES Yun, K. L., Miller, D. C., Moore, K. A., Mitchell, R. S., Oyer, P. E., Stinson, E. B., Robbins, R. C., Reitz, B. A., Shumway, N. E. ELSEVIER SCIENCE INC. 1995: S221-S228

    Abstract

    To compare the durability of the Hancock modified orifice (Hancock MO, model 250 [H-MO]) valve with two other commonly used standard aortic valve bioprostheses, a cohort of 1,602 patients undergoing aortic valve replacement using porcine valves between 1971 and 1990 (excluding simultaneous mitral valve replacement) was analyzed retrospectively using Cox model multivariate techniques. Five hundred sixty-one patients received a composite H-MO valve, 652 received a standard Hancock model 242 (H) valve, and 389 received a Carpentier-Edwards model 2625 (C-E) valve. Mean age was 60 +/- 15 years (+/- 1 standard deviation) (71% male). Follow-up (10,247 patient-years) extended to 15 years and was 97% complete. The main focus of this study was bioprosthetic durability, using The American Association for Thoracic Surgery/The Society of Thoracic Surgeons guidelines to define structural valve deterioration (SVD). Multivariate analysis revealed that (younger) age (p < 10(-5), liver disease (p = 0.02), and 1981 to 1985 operative period (p = 0.012) were the only significant, independent predictors of SVD. In concordance with previous reports, the SVD freedom estimate was greater than 90% at 15 years for patients older than 70 years of age. Hepatic dysfunction had an adverse effect on SVD (estimated freedom from event at 10 years was 34 +/- 17% [standard error of mean] versus 78 +/- 2% for those without liver disease), but this affected only 3% of patients. Interestingly, one operative period (1981 to 1985) was associated with a slightly higher risk of SVD compared to the three other 5-year time windows. Valve type did not emerge as a significant risk factor for SVD.(ABSTRACT TRUNCATED AT 250 WORDS)

    View details for Web of Science ID A1995RT15700035

    View details for PubMedID 7646163

  • SURGICAL-MANAGEMENT OF AORTIC DISSECTION IN PATIENTS WITH THE MARFAN-SYNDROME Smith, J. A., Fann, J. I., Miller, D. C., Moore, K. A., DeAnda, A., Mitchell, R. S., Stinson, E. B., Oyer, P. E., Reitz, B. A., Shumway, N. E. AMER HEART ASSOC. 1994: 235-242
  • TRANSLUMINALLY PLACED ENDOVASCULAR STENT GRAFTS FOR THE TREATMENT OF ABDOMINAL AORTIC AND NON-AORTIC ANEURYSMS Dake, M. D., Semba, C. P., Mitchell, R. S., Zarins, C. K., Miller, D. C. LIPPINCOTT WILLIAMS & WILKINS. 1994: 206-206
  • SURGICAL-MANAGEMENT OF AORTIC DISSECTION OVER 30 YEARS Fann, J. I., Smith, J. A., Miller, D. C., Mitchell, R. S., Moore, K., Oyer, P. E., STINSOUN, E. B., Reitz, B. A., Shumway, N. E. LIPPINCOTT WILLIAMS & WILKINS. 1994: 96-96
  • CLOSED-CHEST CORONARY-ARTERY BYPASS WITH CARDIOPLEGIC ARREST IN THE DOG Stevens, J. H., Siegel, L. C., Mitchell, R. S., Burdon, T. A., Ribakove, G. H., Smith, J. A., STGOAR, F. G., Peters, W. S., Vierra, M. A., Pompili, M. F., Reitz, B. A. LIPPINCOTT WILLIAMS & WILKINS. 1994: 251-251
  • MANAGEMENT OF PATIENTS WITH INTRAMURAL HEMATOMA OF THE THORACIC AORTA Robbins, R. C., McManus, R. P., Mitchell, R. S., LATTER, D. R., Moon, M. R., Olinger, G. N., Miller, D. C. AMER HEART ASSOC. 1993: 1-10
  • EARLY EXPERIENCE WITH CRYOPRESERVED SAPHENOUS-VEIN ALLOGRAFTS AS A CONDUIT FOR COMPLEX LIMB-SALVAGE PROCEDURES Walker, P. J., Mitchell, R. S., McFadden, P. M., James, D. R., MEHIGAN, J. T. MOSBY-ELSEVIER. 1993: 561-569

    Abstract

    The lack of a suitable alternative to autogenous vein is often the limiting factor for complex lower extremity vascular reconstruction, especially when previously placed grafts have failed. Cryopreserved saphenous vein allografts have been used as an alternative conduit. This report reviews our early experience with this conduit in a series of complex redo revascularization procedures for limb salvage when no suitable autogenous vein was available.Thirty-five patients underwent 39 lower extremity bypass grafts on 36 limbs. These patients had undergone a combined total of 72 prior revascularization procedures on the symptomatic limb, an average of two procedures per patient. Only five bypasses were performed as a primary procedure. There were 18 men and 17 women with a mean age of 71 years. Sixteen of the patients had diabetes. Thirty-four bypasses were performed for rest pain or ulceration, four for disabling claudication, and one for replacement of an aneurysmal vein graft. There were 35 femorotibial, three below-knee femoropopliteal, and one femoropedal reconstruction. Twenty-five grafts were constructed with cryopreserved vein only, whereas 14 were composite grafts; 10 were constructed with polytetrafluoroethylene, one with Dacron, and three with spliced native saphenous vein. The mean follow-up was 9 months (range 1 to 25 months).There was one early death (< 30 days) and two late deaths. Two patients died with a patent graft. There have been 12 early graft closures and an additional 17 late failures, resulting in primary cumulative graft patency rates of 67%, 56%, 43%, 28%, and 14% at 1, 3, 6, 12, and 18 months, respectively. Surgically correctable causes, including technical error and anastomotic stenosis, could be identified in 13 of the 29 graft failures. Salvage of failed grafts resulted in secondary cumulative graft patency rates of 87%, 77%, 61%, 46%, and 37% at these same intervals. There was no significant difference in primary or secondary graft patency rates related to diabetes, ABO graft compatibility, graft composition or orientation, indication for surgery, state of the outflow tract, or site of distal anastomosis. Limb salvage was attained in 24 (67%) of the 36 limbs. Two amputations were necessary despite patent grafts.Because of the poor overall graft patency rates, cryopreserved saphenous vein allografts should be used only as a last resort when no alternative autogenous conduit is available. Unless patency rates superior to those achievable with currently available prosthetic or biologic conduits can be attained by adjunctive measures such as routine anticoagulation or immunosuppressive therapy, the use of cryopreserved saphenous vein allografts for lower extremity revascularization should be deferred until improved preparation techniques provide a more durable conduit.

    View details for Web of Science ID A1993MB16500002

    View details for PubMedID 8411463

  • 3-DIMENSIONAL SPIRAL COMPUTED TOMOGRAPHIC ANGIOGRAPHY - AN ALTERNATIVE IMAGING MODALITY FOR THE ABDOMINAL-AORTA AND ITS BRANCHES Rubin, G. D., Walker, P. J., Dake, M. D., Napel, S., Jeffrey, R. B., McDonnell, C. H., Mitchell, R. S., Miller, D. C. MOSBY-ELSEVIER. 1993: 656-665

    Abstract

    We sought to apply a new technique of computed tomographic angiography (CTA) to the preoperative and postoperative assessment of the abdominal aorta and its branches.After a peripheral intravenous contrast injection, the patient is continuously advanced through a spiral CT scanner, while maintaining a 30-second breath-hold. Thirty-five patients with abdominal aortic, renal, and visceral arterial disease have undergone CTA.Diagnostic three-dimensional images were obtained in patients with aortic aneurysms (n = 9), aortic dissections (n = 4), and mesenteric artery stenoses (n = 4). The technique has also been used to assess vessels after operative reconstruction or endovascular intervention in 18 patients. These preliminary studies have correlated well with conventional arteriographic findings. In aneurysmal disease both the lumen and mural thrombus and associated renal artery stenoses are visualized. The true and false channels of aortic dissections and the perfusion source of the visceral vessels are clearly shown; patency of visceral and renal reconstruction or stent placement are confirmed. CTA is relatively noninvasive and can be completed in less time than conventional angiography with less radiation exposure.This initial experience suggests that CTA may be a valuable alternative to conventional arteriography in the evaluation of the aorta and its branches.

    View details for Web of Science ID A1993MB16500013

    View details for PubMedID 8411473

  • INTRAVASCULAR STENTING OF ACUTE EXPERIMENTAL TYPE-B DISSECTIONS Moon, M. R., Dake, M. D., Pelc, L. R., Liddell, R., Castro, L. J., Mitchell, R. S., Miller, D. C. ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS. 1993: 381-388

    Abstract

    To evaluate the efficacy of intravascular stenting for acute aortic dissection, 12 dogs underwent surgical creation of an acute type B dissection. Intravascular ultrasound evaluated luminal diameter, distal propagation, and branch involvement. Three animals underwent no further treatment (control). In 9 dogs, balloon-expandable intravascular stents (15-20 mm) were placed proximally to compress the intimal flap. One dog with a small dissection had complete obliteration of the false lumen after initial stent placement. Six dogs with extension below the diaphragm were initially stented proximally to restore flow; 3 were left with a residual distal false lumen, while 3 had additional stents placed to obliterate their entire false lumen. In the final 2 dogs, proximal stenting resulted only in partial compression of the false lumen. Two animals died within 24 hr due to prolonged hemodynamic instability and aortic rupture at the intimal flap, respectively. Six weeks later, radiologic and histologic evaluation was performed on the 10 surviving animals. All stented true lumens were patent without thrombus formation, and stents were covered by neointima. In dogs with stenting of the entire dissection, the aortic wall had healed and no false lumen was present. However, in all dogs with only proximal obliteration, 1/2 with partial compression, and 2/3 controls, a patent false channel was present indicative of a chronic dissection. Thus, we found that intravascular stents can restore true lumen flow and obliterate the false lumen in experimental dissections; however, stenting limited to the proximal dissection does not prevent formation of a chronic residual patent false lumen.

    View details for Web of Science ID A1993LM66700020

    View details for PubMedID 8331933

  • CLINICAL USE OF INTRAVASCULAR ULTRASOUND IN STENTING ISCHEMIC COMPLICATIONS OF AORTIC DISSECTION Dake, M. D., Wexler, L., Walker, P. J., Mitchell, R. S., Miller, D. C. LIPPINCOTT WILLIAMS & WILKINS. 1992: 364-364
  • RANDOMIZED, PROSPECTIVE ASSESSMENT OF BIOPROSTHESIS DURABILITY - HANCOCK VS CARPENTIER-EDWARDS VALVES Sarris, G. E., Robbins, R. C., Miller, D. C., Mitchell, R. S., Moore, K. A., Stinson, E. B., Oyer, P. E., Starnes, V. A., Shumway, N. E. LIPPINCOTT WILLIAMS & WILKINS. 1992: 496-496
  • MANAGEMENT OF INTRAMURAL HEMATOMA OF THE THORACIC AORTA Robbins, R. C., MACMANUS, R. P., Mitchell, R. S., LATTER, D. R., Olinger, G. N., Miller, D. C. LIPPINCOTT WILLIAMS & WILKINS. 1992: 12-12
  • AORTIC DISSECTION RESULTING FROM TEAR OF TRANSVERSE ARCH - IS CONCOMITANT ARCH REPAIR WARRANTED Yun, K. L., Glower, D. D., Miller, D. C., Fann, J. I., Mitchell, R. S., White, W. D., Rankin, J. S., Wolfe, W. G., Shumway, N. E. MOSBY-ELSEVIER. 1991: 355-370

    Abstract

    Forty-seven patients with aortic dissection resulting from a primary tear located in the transverse aortic arch underwent surgical treatment. Twenty-six patients had acute type A, 7 had acute type B, 7 had chronic type A, and 7 had chronic type B aortic dissections. Of the 33 patients with acute dissections, 11 (7 acute type A and 4 acute type B) underwent concomitant arch repair with an operative (less than or equal to 30 days) mortality rate of 55% (35% to 73%, +/- 1 asymmetric 70% confidence limit) (2 of 7 acute type A and 4 of 4 acute type B). Concomitant arch repair was omitted in 22 patients with acute dissections (19 acute type A and 3 acute type B); the operative mortality rate was 41% (29% to 54%) (7 of 19 acute type A and 2 of 3 acute type B) (p = not significant versus arch repair). The overall survival rate for those with arch repair was 45% +/- 15% (+/- 1 standard error of the estimate) at 4 years, compared with 43% +/- 11% for patients without arch repair (p = not significant). Considering the type of dissection, the 4-year survival estimate for patients with acute type A dissections who underwent arch repair (5 hemiarch and 2 total arch) was 71% +/- 17% (versus 44% +/- 12% for acute type A patients without arch repair). There were no survivors among the 4 patients with acute type B dissections who had an arch repair (1 hemiarch and 3 total arch), whereas patients with acute type B dissections who did not undergo concomitant arch repair had a 4-year survival estimate of 33% +/- 27% (p = not significant versus arch repair). Four other patients with acute type B dissections resulting from an arch tear were managed medically and tended to have a slightly better prognosis (2-year survival estimate of 75% +/- 22% versus 14% +/- 13% for all surgically treated acute type B patients), but again this difference was not statistically significant. Multivariate analysis of the 47 surgical patients revealed that advanced age (p = 0.0008), preoperative dissection complications (p = 0.02), and other coexistent medical problems (p = 0.03) were the only significant, independent determinants of overall mortality. Initial arch repair was not a significant predictor. Nine percent (2/22) of patients with acute type A dissections who initially underwent isolated ascending aortic replacement required subsequent arch replacement; 1 died after reoperation.(ABSTRACT TRUNCATED AT 400 WORDS)

    View details for Web of Science ID A1991GE66000004

    View details for PubMedID 1881176

  • IMPORTANCE OF THE ANTERIOR AND POSTERIOR MITRAL CHORDAE ON GLOBAL LEFT-VENTRICULAR SYSTOLIC FUNCTION Hansen, D. E., CAHILL, P. D., DeCampli, W. M., HARRISON, D. C., HANDEN, C., Derby, G., Mitchell, R. S., Miller, D. C. ELSEVIER SCIENCE INC. 1986: A249-A249
  • CRITICAL-EVALUATION OF 111-IN-WHITE CELL SCAN FOR DIAGNOSING PROSTHETIC GRAFT INFECTION McDougall, I. R., Brunner, M. C., Mitchell, R. S., Baldwin, J. C., James, D. R., Olcott, C., MEHIGAN, J. T., Miller, D. C. LIPPINCOTT-RAVEN PUBL. 1985: P18-P18
  • SEVERING THE CHORDAE TENDINEAE REDUCES LEFT-VENTRICULAR SYSTOLIC PERFORMANCE IN DOGS Hansen, D. E., DeCampli, W. M., Mitchell, R. S., Derby, G. C., Miller, D. C. LIPPINCOTT WILLIAMS & WILKINS. 1985: 485-485
  • INDEPENDENT DETERMINANTS OF OPERATIVE MORTALITY FOR PATIENTS WITH AORTIC DISSECTIONS Miller, D. C., Oyer, P. E., Mitchell, R. S., Stinson, E. B., Jamieson, S. W., Shumway, N. E. AMER HEART ASSOC. 1983: 15-15

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