Bio

Clinical Focus


  • Vascular Surgery

Academic Appointments


Administrative Appointments


  • Professor of Surgery, Stanford University (2012 - Present)
  • Associate Professor of Surgery, Stanford University (2007 - 2012)
  • Section Chief, Vascular Surgery, Palo Alto VA Medical Center (2007 - Present)
  • Assistant Professor of Surgery, Baylor College of Medicine (2005 - 2007)

Professional Education


  • Residency:UCSD Medical Center (2003) CA
  • Board Certification: Vascular Surgery, American Board of Surgery (2006)
  • Fellowship:Baylor College of Medicine (2005) TX
  • Board Certification: General Surgery, American Board of Surgery (2004)
  • Internship:UCSD Medical Center (1999) CA
  • Medical Education:New York Medical College (1998) NY

Research & Scholarship

Current Research and Scholarly Interests


Dr. Zhou’s vascular research laboratory focuses on molecular mechanisms of and treatment strategies for intimal hyperplasia. Her specific clinical research interests are re-stenosis following endovascular interventions and outcome measures following carotid interventions. Through collaboration with Stanford investigators and investigators at Baylor College of Medicine, plaque morphology and radiographic imaging are correlated. Furthermore, innovational treatment approaches for cardiovascular diseases are investigated using a well-developed wire-injury rodent model. She is also the principle invetigator for several clinical trials that are funded by AHA and industries examining outcomes following cerebrovascular, aortic, and lower extremity interventions.

Clinical Trials


  • Prevention of Colon Ischemia During Aortic Aneurysm (AAA) Repair Not Recruiting

    Patients undergoing surgery on their Aorta can get ischemia, a lack of blood flow, to their intestines and colon. This is very serious, as 2 out of 3 patients who have this problem die before leaving the hospital. A device developed by Spectros, called T-Stat, is approved by the US FDA to detect ischemia, and has been reported to detect ischemia in AAA aneurysm surgery and stenting, allowing the surgeon or interventional radiologist to take action quickly, while the colon ischemia is still treatable. This purpose of this study is to establish how T-Stat can best be used to prevent deaths.

    Stanford is currently not accepting patients for this trial. For more information, please contact Jason Lee, (650) 725 - 5227.

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  • Long-term Neurocognitive Sequelae of Subclinical Microembolization During Carotid Interventions Recruiting

    Microembolization is commonly associated with carotid artery stenting (CAS), but our understanding of subclinical microembolization is superficial. Through collaborative effects of multidisciplinary team-experts, novel approaches, and longitudinal evaluations, we hope to better understand the clinical significance and long-term cognitive effects of microemboli. This proposal may change our current clinical practice by providing a better outcome measure for carotid interventions and improving outcomes of CAS procedures through risk factor stratification. Our central hypothesis is that development of subclinical microemboli is associated with decline in cognitive function following CAS and that the risk of development of microemboli themselves is associated with patient- and procedure-related factors. We hope that this prospective study will help to clarify these important issues in the era of rapidly evolving percutaneous interventions.

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  • Plaque Removal Versus Open Bypass Surgery For Critical Limb Ischemia Not Recruiting

    To compare the outcome of bypass surgery and plaque excision for treatment of critical limb ischemia in the lower limbs

    Stanford is currently not accepting patients for this trial. For more information, please contact Jason Lee, (650) 725 - 5227.

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Teaching

2013-14 Courses


Postdoctoral Advisees


Publications

Journal Articles


  • Contralateral microemboli following carotid artery stenting in patients with a contralateral internal carotid artery occlusion JOURNAL OF VASCULAR SURGERY Casey, K., Hitchner, E., Lane, B., Zhou, W. 2013; 58 (3): 794-797

    Abstract

    Subclinical microembolization identified on diffusion-weighted magnetic resonance imaging is recognized as an important outcome measure for carotid revascularization procedures. It is generally believed that arch manipulation is the primary reason for developing microemboli in the contralateral hemisphere during carotid artery stenting. However, we identified three patients who developed postprocedure microemboli of the contralateral hemisphere despite a known chronic contralateral internal carotid artery occlusion. Our cases highlight that ipsilateral microemboli may be an underappreciated but an important source of contralateral lesions through patent intracranial collateral pathways.

    View details for DOI 10.1016/j.jvs.2012.11.114

    View details for Web of Science ID 000323616800032

    View details for PubMedID 23478504

  • Monitoring of fetal radiation exposure during pregnancy JOURNAL OF VASCULAR SURGERY Chandra, V., Dorsey, C., Reed, A. B., Shaw, P., Banghart, D., Zhou, W. 2013; 58 (3): 710-714

    Abstract

    BACKGROUND: One unique concern of vascular surgeons and trainees is radiation exposure associated with increased endovascular practice. The safety of childbearing is a particular worry for current and future women in vascular surgery. Little is known regarding actual fetal radiation exposure. This multi-institutional study aimed to evaluate the radiation dosages recorded on fetal dosimeter badges and compare them to external badges worn by the same cohort of women. METHODS: All women who declared pregnancy with potential radiation exposure were required to wear two radiation monitors at each institution, one outside and the other inside the lead apron. Maternal (external) and fetal monitor dosimeter readings were analyzed. Maternal radiation exposures prior to, during, and postpregnancy were also assessed to determine any associated behavior modification. RESULTS: Eighty-one women declared pregnancy from 2008 to 2011 and 32 had regular radiation exposure during pregnancy. Maternal whole-body exposures ranged from 21-731 mrem. The average fetal dosimeter recordings for the cohort rounded to zero. Only two women had positive fetal dosimeter recordings; one had a single recording of 3 mrem and the other had a single recording of 7 mrem. There was no significant difference between maternal exposures prior to, during, and postpregnancy. CONCLUSIONS: Lack of knowledge of fetal radiation exposure has concerned many vascular surgeons, prompting them to wear double lead aprons during pregnancy, and perhaps prevented numerous other women from entering the field. Our study showed negligible radiation exposure on fetal monitoring suggesting that with the appropriate safety precautions, these concerns may be unwarranted.

    View details for DOI 10.1016/j.jvs.2013.01.052

    View details for Web of Science ID 000323616800019

    View details for PubMedID 23591191

  • Prospective neurocognitive evaluation of patients undergoing carotid interventions JOURNAL OF VASCULAR SURGERY Zhou, W., Hitchner, E., Gillis, K., Sun, L., Floyd, R., Lane, B., Rosen, A. 2012; 56 (6): 1571-1578

    Abstract

    Distal cerebral embolization is a known complication of carotid interventions. We prospectively investigated whether subclinical microembolization seen on postoperative magnetic resonance imaging (MRI) leads to cognitive deficits in patients undergoing carotid revascularization procedures.Patients undergoing carotid interventions and eligible for MRI scanning were recruited. Among 247 patients who received preoperative and postoperative MRI evaluations, 51 also completed neuropsychologic testing before and at 1 month after their procedure. Cognitive evaluation included the Rey Auditory Verbal Learning Test (RAVLT) for memory evaluation and the Mini-Mental State Examination (MMSE) for general cognitive impairment screening.The 51 patients (all men), comprising 16 with carotid artery stenting (CAS) and 35 with carotid endarterectomy (CEA), were a mean age of 71 years (range, 54-89 years). Among them, 27 patients (53%) were symptomatic preoperatively, including 11 who had prior stroke and 16 who had prior preoperative transient ischemic attack symptoms. Most patients had significant medical comorbidities, including hypertension (96%), diabetes (31.3%), coronary artery disease (47%), and chronic obstructive pulmonary disease (15.7%). Two patients (4%) had prior ipsilateral CEA and eight had contralateral carotid occlusion (15.7%). Memory decline evident on RAVLT was identified in eight CAS patients and 13 CEA patients. Eleven patients had evidence of procedure-related microemboli. Although there was no significant difference in baseline cognitive function or memory change between the CEA and CAS cohorts, the CAS cohort had a significantly higher incidence of microembolic lesions. Multivariate regression analysis showed that procedure-related microembolization was associated with memory decline (P = .016) as evident by change in RAVLT. A history of neurologic symptoms was significantly associated with poor baseline cognitive function (MMSE; P = .03) and overall cognitive deterioration (change in MMSE; P = .026), as determined by Wilcoxon rank sum test and linear regression analysis, respectively.Although CEA and CAS are effective in stroke prevention, with minimal neurologic complication, neurocognitive effects remain uncertain. Procedure-associated microembolization and pre-existing neurologic symptoms are associated with poor baseline cognitive function and memory decline after the procedures. Further comprehensive cognitive evaluation to determine the benefit of carotid interventions is warranted.

    View details for DOI 10.1016/j.jvs.2012.05.092

    View details for Web of Science ID 000311489800014

    View details for PubMedID 22889720

  • VALIDATION OF A POWER LAW MODEL IN UPPER EXTREMITY VESSELS: POTENTIAL APPLICATION IN ULTRASOUND BLEED DETECTION ULTRASOUND IN MEDICINE AND BIOLOGY Wang, A. S., Liang, D. H., Bech, F., Lee, J. T., Zarins, C. K., Zhou, W., Taylor, C. A. 2012; 38 (4): 692-701

    Abstract

    Vascular ultrasound can provide quick and reliable diagnosis of arterial bleeding but it requires trained and experienced personnel. Development of automated sonographic bleed detection methods would potentially be valuable for trauma management in the field. We propose a detection method that (1) measures blood flow in a trauma victim, (2) determines the victim's expected normal limb arterial flow using a power law biofluid model where flow is proportional to the vessel diameter taken to a power of k and (3) quantifies the difference between measured and expected flow with a novel metric, flow split deviation (FSD). FSD was devised to give a quantitative value for the likelihood of arterial bleeding and validated in human upper extremities. We used ultrasound to demonstrate that the power law with k = 2.75 appropriately described the normal brachial artery bifurcation geometry and adequately determined the expected normal flows. Our metric was then applied to three-dimensional (3-D) computational models of forearm bleeding and on dialysis patients undergoing surgical construction of wrist arteriovenous fistulas. Computational models showed that larger sized arterial defects produced larger flow deviations. FSD values were statistically higher (paired t-test) for arms with fistulas than those without, with average FSDs of 0.41 ± 0.12 and 0.047 ± 0.021 (mean ± SD), respectively. The average of the differences was 0.36 ± 0.12 (mean ± SD).

    View details for DOI 10.1016/j.ultrasmedbio.2011.12.016

    View details for Web of Science ID 000301181300018

    View details for PubMedID 22341050

  • Concurrent Treatment of Acute Pancreatitis and Multiple Visceral Artery Aneurysms Using Endovascular Techniques VASCULAR AND ENDOVASCULAR SURGERY Mitkov, M., Al-Khatib, W. K., Zhou, W. 2012; 46 (3): 283-286

    Abstract

    Multiple aneurysms involving the celiac axis are extremely rare. Celiac artery aneurysms account for only 4% of all visceral aneurysms with 40% having concomitant aneurysms such as gastroduodenal artery (GDA) aneurysms. Development of a GDA aneurysm is associated with pancreatitis. If a GDA aneurysm ruptures, traditional repair is through open surgical techniques with significant morbidity and mortality as up to 50% occur in the setting of chronic pancreatitis. However, a ruptured GDA aneurysm causing pancreatitis has not been described previously. We report a case of successful endovascular treatment of a ruptured GDA aneurysm and concomitant celiac artery aneurysm leading to the resolution of acute pancreatitis.

    View details for DOI 10.1177/1538574412440509

    View details for Web of Science ID 000303651900014

    View details for PubMedID 22566183

  • Therapeutic Potential for Protein Kinase C Inhibitor in Vascular Restenosis JOURNAL OF CARDIOVASCULAR PHARMACOLOGY AND THERAPEUTICS Ding, R. Q., Tsao, J., Chai, H., Mochly-Rosen, D., Zhou, W. 2011; 16 (2): 160-167

    Abstract

    Vascular restenosis, an overreaction of biological response to injury, is initialized by thrombosis and inflammation. This response is characterized by increased smooth muscle cell migration and proliferation. Available pharmacological treatments include anticoagulants, antiplatelet agents, immunosuppressants, and antiproliferation agents. Protein kinase C (PKC), a large family of serine/threonine kinases, has been shown to participate in various pathological stages of restenosis. Consequently, PKC inhibitors are expected to exert a wide range of pharmacological activities therapeutically beneficial for restenosis. In this review, the roles of PKC isozymes in platelets, leukocytes, endothelial cells, and smooth muscle cells are discussed, with emphasis given to smooth muscle cells. We will describe cellular and animal studies assessing prevention of restenosis with PKC inhibitors, particularly targeting -?, -?, -?, and -? isozymes. The delivery strategy, efficacy, and safety of such PKC regulators will also be discussed.

    View details for DOI 10.1177/1074248410382106

    View details for Web of Science ID 000290562100005

    View details for PubMedID 21183728

  • Matrix metalloproteinases modulated by protein kinase C epsilon mediate resistin-induced migration of human coronary artery smooth muscle cells JOURNAL OF VASCULAR SURGERY Ding, Q., Chai, H., Mahmood, N., Tsao, J., Mochly-Rosen, D., Zhou, W. 2011; 53 (4): 1044-1051

    Abstract

    Emerging evidence showed that resistin induces vascular smooth muscle cell (VSMC) migration, a critical step in initiating vascular restenosis. Adhesion molecule expression and cytoskeletal rearrangement have been observed in this progress. Given that matrix metalloproteinases (MMPs) also regulate cell migration, we hypothesized that MMPs may mediate resistin-induced VSMC migration.Human VSMCs were treated with recombinant human resistin at physiologic (10 ng/mL) and pathologic (40 ng/mL) concentrations for 24 hours. Cell migration was determined by the Boyden chamber assay. MMP and tissue inhibitor metalloproteinase (TIMP) mRNA and protein levels were measured with real-time PCR and ELISA. MMP enzymatic activity was measured by zymography. In another experiment, neutralizing antibodies against MMP-2 and MMP-9 were coincubated with resistin in cultured VSMCs. The regulation of MMP by protein kinase C (PKC) was determined by ?V1-2, a selective PKC? inhibitor.Resistin-induced smooth muscle cell (SMC) migration was confirmed by the Boyden chamber assay. Forty nanograms/milliliter resistin increased SMC migration by 3.7 fold. Additionally, resistin stimulated MMP-2 and -MMP9 mRNA and protein expressions. In contrast, the TIMP-1 and TIMP-2 mRNA levels were inhibited by resistin. Neutralizing antibodies against MMP-2 and MMP-9 effectively reversed VSMC migration. Furthermore, resistin activated PKC?, but selective PKC? inhibitor suppressed resistin-induced MMP expression, activity, and cell migration.Our study confirmed that resistin increased vascular smooth muscle cell migration in vitro. In terms of mechanism, resistin-stimulated cell migration was associated with increased MMP expression, which was dependent on PKC? activation.

    View details for DOI 10.1016/j.jvs.2010.10.117

    View details for Web of Science ID 000289012600023

    View details for PubMedID 21277149

  • Radiation exposure of vascular surgery patients beyond endovascular procedures JOURNAL OF VASCULAR SURGERY Zhou, W. 2011; 53: 39S-43S

    Abstract

    Medical imaging evaluations provide valuable information and are often imperative in the care of our patients. Radiation exposure in patients who undergo medical imaging procedures is not routinely monitored and the associated risks are often underestimated.Radiation exposure associated with computed tomography (CT) angiography and coronary intervention is reviewed.Vascular surgeons are often involved in the decision-making process in roughly 30% of CT scans performed that are believed to be unnecessary. Society for Vascular Surgery (SVS) practice guidelines for patients with abdominal aortic aneurysms recommended eliminating a 6-month contrast surveillance CT if no endoleak was observed at 1 month after endovascular aneurysm repair (EVAR). Ultrasound and aortic duplex can help eliminate some of the CT scans.Vascular surgeons must remain vigilant in monitoring radiation exposure for their patients who have potential for coronary and vascular imaging with radiation. Judicious use of alternative imaging modalities when possible and maintaining the dose as low as reasonably achievable (ALARA) is the responsibility of vascular surgeons.

    View details for DOI 10.1016/j.jvs.2010.06.176

    View details for Web of Science ID 000286085300009

    View details for PubMedID 20843624

  • Resistin and Cardiovascular Disease TRENDS IN CARDIOVASCULAR MEDICINE Ding, Q., White, S. P., Ling, C., Zhou, W. 2011; 21 (1): 20-27

    Abstract

    Resistin has been implicated in coronary atherosclerotic disease and congestive heart failure. Recent studies have extended its involvement in peripheral artery disease. Despite some controversial data, the mainstream clinical literature supports that resistin is associated with both coronary and peripheral artery diseases including ischemic stroke. In this review, the multiple roles of resistin as screening, diagnostic, and prognostic marker for cardiovascular disease are discussed. The independence of resistin in disease prediction and diagnosis appears complicated by its confounders, such as C-reactive protein. A clear-cut biomarker function of resistin in cardiovascular disease needs be clarified by additional large-scale, well-designed prospective studies.

    View details for Web of Science ID 000304732700004

    View details for PubMedID 22498016

  • In Vivo Assessment of the Effects of Ginsenoside Rb1 on Intimal Hyperplasia in ApoE Knockout Mice JOURNAL OF SURGICAL RESEARCH Chai, H., Schultz, G., Aghaie, K., Zhou, W. 2010; 162 (1): 26-32

    Abstract

    This study investigated the effects of ginsenoside Rb1 (Rb1) on injury-induced intimal hyperplasia in ApoE knock out (ApoE -/-) mice. We also examined the value of an ultrasound micro-image system in dynamic monitoring of lumen diameter and flow velocity.After guide wire injury of the distal left common carotid artery (CCA), ApoE-/- mice were treated with intraperitoneal infusion of normal saline (NS), homocysteine (Hcy), ginsenoside Rb1 (Rb1), or Hcy+Rb1 for 4 wk. Bilateral CCA luminal diameters and flow velocities were measured with an ultrasound micro-image system before surgery and weekly afterwards. Following the final ultrasound, CCAs were harvested and analyzed for intima-medium thickness ratios.Progressive reduction in luminal diameters and increase in flow velocity of the injured left distal CCA segment were observed using ultrasound micro-imaging system in all groups compared with the relatively stable left proximal CCA and right CCA. The NS and Hcy groups had significantly higher degree of diameter reduction compared with the Rb1 and Rb1+Hcy groups. The ultrasound findings were consistent with histology analyses at 4 wk post-op.The study suggested that Rb1 attenuated the effects of Hcy on injured carotid arteries of ApoE -/- mice. The study also showed that ultrasound micro-image system was a reliable tool in monitoring luminal reduction after injury in a murine model. This study establishes a fundamental step of in vivo monitoring of the therapeutic effects of agents in a murine model without sacrificing the animals.

    View details for DOI 10.1016/j.jss.2010.01.026

    View details for Web of Science ID 000279071500006

    View details for PubMedID 20421114

  • Distribution of Inflammatory Mediators in Carotid and Femoral Plaques JOURNAL OF THE AMERICAN COLLEGE OF SURGEONS Zhou, W., Chai, H., Ding, R., Lam, H. Y. 2010; 211 (1): 92-98

    Abstract

    Although atherosclerosis is a known systemic process, carotid and femoral atherosclerotic plaques are associated with distinctive complications and therapeutic outcomes. The purpose of this study was to evaluate inflammatory markers associated with carotid and femoral plaques.Carotid and femoral endarterectomy specimens were harvested from surgical patients. The carotid specimens were further sectioned into central, peripheral, and relatively normal regions. Expressions of matrix metalloproteinase (MMP)-2 and MMP-9 in carotid and femoral specimens were compared and the distributions of MMP-2, MMP-9, and CD40 within the carotid specimens were further analyzed. Messenger RNA (mRNA) levels were measured with real-time polymerase chain reaction and proteins with ELISA assay and Western blot.Despite no significant difference in the MMP-2 mRNA levels between carotid and femoral specimens, the common femoral specimens had significantly lower MMP-2 protein production and higher MMP-9 mRNA and protein expressions than those of the carotid specimens (p = 0.015, p = 0.03, and p = 0.034, respectively). Among carotid specimens, MMP-2 mRNA level was significantly lower in the central region (p < 0.01) and consistent with the distribution pattern of MMP-2 proteins. Interestingly, despite significantly lower MMP-9 mRNA expression in the central region of carotid plaques, active MMP-9 protein level was significantly higher. CD40 mRNA and protein levels were also higher in the central region. Immunohistochemistry analyses showed substantially increased macrophages and CD40 in the central region of the carotid plaques.This study emphasizes that femoral and carotid plaques are distinct entities and that distribution of inflammatory molecular markers varied within these advanced atherosclerotic plaques. Additional analyses are warranted.

    View details for DOI 10.1016/j.jamcollsurg.2010.02.054

    View details for Web of Science ID 000280120400013

    View details for PubMedID 20610254

  • Long-term radiographic outcomes of microemboli following carotid interventions JOURNAL OF VASCULAR SURGERY Zhou, W., Dinishak, D., Lane, B., Hernandez-Boussard, T., Bech, F., Rosen, A. 2009; 50 (6): 1314-1319

    Abstract

    Subclinical microemboli on diffusion-weighted magnetic resonance imaging (DWI) have been identified immediately following carotid revascularization procedures, but the clinical significance and long-term effects are largely unknown. The purpose of this study was to evaluate long-term radiographic outcomes of these DWI lesions.Patients who underwent perioperative magnetic resonance imaging (MRI) evaluations for carotid interventions at a single institution from July 2004 to December 2008 were evaluated, particularly those who had additional follow-up MRI. DWI with apparent diffusion coefficient (ADC), fluid-attenuated inversion recovery (FLAIR), and T2-weighted MRI images were compared to determine long-term effect of microemboli.One-hundred sixty-eight consecutive patients (68 carotid artery stenting [CAS] and 100 carotid endarterectomy [CEA]) who received perioperative MRI were included. All CAS were performed with an embolic protection device. The incidence of microemboli was significantly higher in the CAS group than the CEA group (46.3% and 12%, respectively, P < .05) despite a relative low incidence of procedure-associated neurologic symptoms in both groups (2.9% vs 2%). Thirty patients (16 CAS and 14 CEA) who had follow-up MRI were further analyzed and a total of 50 postoperative DWI lesions (mean size 46.57 mm(2); range 16 to 128 mm(2)) were identified among them. During a mean MRI follow-up of 10 months (range, 2 to 23 months), residual MRI abnormalities were only identified in DWI lesions larger than 60 mm(2) on postoperative MRI and on postoperative FLAIR images (n = 5, P < .001). The CEA group had fewer but larger ipsilateral distributed emboli (total 12 lesions, mean 79 mm(2)) compared with the CAS group (total 38 lesions, mean 27.5 mm(2), P < .05).The majority of microemboli do not have long-term radiographic sequelae. Size and hyperintensity on postoperative FLAIR are predictive of residual brain structure abnormality, and further neurocognitive evaluations are warranted.

    View details for DOI 10.1016/j.jvs.2009.07.105

    View details for Web of Science ID 000272860900010

    View details for PubMedID 19837533

  • Ginsenoside Rb1 Attenuates Homocysteine-Augmented Guidewire Injury-Induced Intinnal Hyperplasia in Mice JOURNAL OF SURGICAL RESEARCH Chai, H., Dong, Y., Wang, X., Zhou, W. 2009; 157 (2): 193-198

    Abstract

    Intimal hyperplasia (IH) is the primary cause for post-angioplasty restenosis. The purpose of this study is to investigate the effects of homocysteine (Hcy) and ginsenoside Rb1 (Rb1) on IH using a guidewire injury animal model.In 12-wk-old C57BL/6J mice, the left common carotid artery (CCA) was denudated with a guidewire and the right CCA was used as the uninjured control. They were treated with saline (NS), Hcy, Rb1, or Hcy + Rb1 for 4 wk prior to sacrifice. Animals were sacrificed at 4, 6, or 8 wk. Both CCAs were harvested and intimal-medium thickness (IMT) ratios were calculated. Local macrophage distribution was also studied.Histology analyses demonstrated consistent internal elastic lamina disruption and focal IH in the injured CCA segments. The degree of IH correlated to the lengths of time following injury. Hcy treated group had significant increase in IMT compared with the NS group (P < 0.05), while Rb1 group was similar to the NS group. In addition, Hcy + Rb1 group showed significant improvement in IMT compared with Hcy group (P < 0.01). Furthermore, Hcy significantly increased local macrophage content as compared with either lesion alone or Rb1 treated animals.Our study showed that Hcy increased the degree of IH and macrophage content in the injured CCA and that Rb1 attenuated these adverse effects. These changes might be mediated through antioxidative effects of Rb1. Our data suggests a potential clinical application of ginseng in controlling Hcy-related vascular injuries.

    View details for DOI 10.1016/j.jss.2008.07.005

    View details for Web of Science ID 000276650200010

    View details for PubMedID 19041102

  • Soluble CD40 ligand induces human coronary artery smooth muscle cells proliferation and migration SURGERY Chai, H., Aghaie, K., Zhou, W. 2009; 146 (1): 5-11

    Abstract

    Clinical data have shown that an increased level of serum soluble CD40 ligand (sCD40L) is associated with atherosclerogenesis. We hypothesize that sCD40L induces proliferation and migration of vascular smooth muscle cells (VSMCs) through activation of matrix metalloproteinases (MMPs).Human VSMCs were treated with sCD40L (1 or 5 microg/mL). Cell proliferation and migration were studied using a nonradioactive cell proliferation assay (MTT) and a modified Boyden chamber combined with a scrape-wound assay, respectively. Messenger RNA (mRNA) and protein levels of MMP-2 and MMP-9 were measured with real-time polymerase chain reaction and enzyme-linked immunosorbent assays. Neutralizing antibodies against MMP-2 or MMP-9 were used to evaluate their effects on sCD40L-induced cell proliferation and migration.MTT assay showed a 35% increase in cell proliferation in the high-dose (5 microg/mL) sCD40L-treated group. Cell migration was also increased by 33% (Transwell assay) to 3-fold (scrape-wound assay) after high-dose sCD40L treatment. When cells were treated with 5 microg/mL of sCD40L for 24 hours, significant decreases in MMP-2 and increases in MMP-9 mRNA and protein levels were observed. Neutralizing antibodies against MMP-9 effectively blocked sCD40L-induced cell proliferation and migration.This study suggests that sCD40L increases VSMC proliferation and migration through the MMP-9 pathway, which may be a potential mechanism through which sCD40L induces intimal hyperplasia and atherosclerosis.

    View details for DOI 10.1016/j.surg.2009.04.004

    View details for Web of Science ID 000267498600002

    View details for PubMedID 19541004

  • SUBCAPSULAR HEMATOMA OF THE KIDNEY SECONDARY TO PAINTBALL PELLET INJURIES JOURNAL OF EMERGENCY MEDICINE Guerrero, M. A., Zhou, W., El Sayed, H. F., Kougias, P., Lin, P. H. 2009; 36 (3): 300-301
  • Reduction of postprocedure microemboli following retrospective quality assessment and practice improvement measures for carotid angioplasty and stenting JOURNAL OF VASCULAR SURGERY Tedesco, M. M., Dalman, R. L., Zhou, W., Coogan, S. M., Lane, B., Lee, J. T. 2009; 49 (3): 607-612

    Abstract

    We have previously demonstrated a 70% incidence of microemboli on diffusion weighted magnetic resonance imaging (DW-MRI) following carotid angioplasty and stenting (CAS). The purpose of this study is to compare the incidence of microemboli in two distinct time periods when procedural modifications were implemented into a CAS program.Following a retrospective quality review of our CAS cohort (n = 27) from November 2004 through April 2006 (period 1), we enrolled patients (n = 20) from May 2006 through February 2008 (period 2) undergoing CAS into a prospective cohort that included obtaining pre- and postprocedure DW-MRI exams. Procedural modifications during period 2 included the preferential use of closed-cell systems (60% vs 0% in period 1), early heparinization at the initiation of arterial access, and elimination of an arch angiogram. The hospital records of these 47 patients were reviewed; symptoms, comorbidities, lesion characteristics, periprocedural information, and postoperative outcomes were collected. The incidence and location of acute, postprocedural microemboli were determined using DW-MRIs.Twenty (74%) CAS patients from period 1 and seven (35%) patients from period 2 demonstrated acute microemboli on postprocedural DW-MRI (P = .02). The mean number of microemboli in period 1 was 4.1 +/- 5.3 vs 1.5 +/- 2.7 during period 2 (P = .04). Two of the 27 patients (7.4%) during period 1 experienced temporary neurologic changes that resolved within 36 hours. None of the patients during period 2 exhibited any neurologic changes. Patient demographics, comorbidities, and presenting symptoms were similar between the two groups except for smoking prevalence, female presence, and obesity (BMI > 30). Period 2 patients when compared with period 1 had more technically challenging anatomy with more calcified lesions (68% vs 27%), longer lesions (15.9 mm vs 8.2 mm), and higher incidence of ulceration (55% vs 27%) (all P < .04).Despite successful performance of 47 consecutive CAS procedures without permanent neurologic sequelae, significant reductions in periprocedural embolic events as identified via DW-MRI lesions may be achieved through implementation of quality improvement measures identified through continuous outcome analysis. The long-term neurologic benefits associated with reduced subclinical neurologic events remains to be determined.

    View details for DOI 10.1016/j.jvs.2008.10.031

    View details for Web of Science ID 000263802000015

    View details for PubMedID 19135833

  • Fate of the external carotid artery following carotid interventions. The International journal of angiology : official publication of the International College of Angiology, Inc Casey, K., Zhou, W., Tedesco, M. M., Al-Khatib, W. K., Hernandez-Boussard, T., Bech, F. 2009; 18 (4): 173-176

    Abstract

    The external carotid artery (ECA) is an important collateral pathway for cerebral blood flow. Carotid artery stenting (CAS) typically crosses the ECA, while carotid endarterectomy (CEA) includes deliberate ECA plaque removal. The purpose of the present study was to compare the long-term patency of the ECA following CAS and CEA as determined by carotid duplex ultrasound.Duplex ultrasounds and hospital records were reviewed for consecutive patients undergoing CAS between February 2002 and April 2008, and were compared with those undergoing CEA in the same time period. Preoperative and postoperative ECA peak systolic velocities were normalized to the common carotid artery (CCA) as ECA/CCA ratios. A significant (80% or greater) ECA stenosis was defined as an ECA/CCA ratio of 4.0. A change of ratio by more than 1 was defined as significant. Data were analyzed using Student's t test and ?(2) analysis.A total of 86 CAS procedures in 83 patients were performed (81 men, mean age 69.9 years). Among them, 38.4% of patients had previous CEA, 9.6% of whom had contralateral internal carotid artery occlusion. Sixty-seven CAS and 65 CEA patients with complete duplex data in the same time period were included in the analyses. There was no difference in the incidence of severe ECA stenosis on preoperative ultrasound evaluations. During a mean follow-up of 34 months (range four to 78 months), three postprocedure ECA occlusions were found in the CAS group. The likelihood of severe stenosis or occlusion following CAS was 28.3%, compared with 11% following CEA (P<0.025). However, 62% of CEA patients and 57% of CAS patients had no significant change in ECA status. Reduction in the patient's degree of ECA stenosis was observed in 9.4% of CAS versus 26.6% of CEA patients. Overall, immediate postoperative ratios of both groups were slightly improved, but there was a trend of more disease progression in the CAS group during follow-up.CAS is associated with a higher incidence of post-procedure ECA stenosis. Despite the absence of neurological symptoms, a trend toward late disease progression of ECA following CAS warrants long-term evaluation.

    View details for PubMedID 22477547

  • Commentary on "hemodynamic changes associated with carotid artery interventions". Perspectives in vascular surgery and endovascular therapy Zhou, W. 2008; 20 (3): 297-298

    View details for DOI 10.1177/1531003508324855

    View details for PubMedID 18930941

  • Prolonged renal artery occlusion after endovascular aneurysm repair: Endovascular rescue and renal function salvage JOURNAL OF VASCULAR SURGERY Hedayati, N., Lin, P. H., Lumsden, A. B., Zhou, W. 2008; 47 (2): 446-449

    Abstract

    Albeit uncommon, delayed renal dysfunction after endovascular abdominal aortic aneurysm repair (EVAR) can be attributed to proximal stent graft migration or unrecognized partial renal artery coverage. We report two patients who were found to have renal artery occlusion 1 week after EVAR with Zenith (Cook, Bloomington, Ind) infrarenal devices despite patent bilateral renal arteries shown on completion angiograms. Both patients presented with prolonged symptoms of acute renal failure, and uremic encephalopathy developed in one. Both patients were successfully treated with renal artery stenting, which led to symptom resolution and recovery of renal function. Our cases highlight that although postoperative renal occlusion after EVAR is rare, a high index of suspicion and urgent intervention are warranted because renal salvage can be achieved after prolonged ischemic insult.

    View details for DOI 10.1016/j.jvs.2007.08.019

    View details for Web of Science ID 000252685000035

    View details for PubMedID 17950560

  • Ultrasound criteria for severe in-stent restenosis following carotid artery stenting JOURNAL OF VASCULAR SURGERY Zhou, W., Felkai, D. D., Evans, M., McCoy, S. A., Lin, P. H., Kougias, P., El-Sayed, H. F., Lumsden, A. B. 2008; 47 (1): 74-80

    Abstract

    In-stent restenosis (ISR) is a known complication following carotid artery stenting (CAS). However, ultrasound criteria determining ISR are not well established. We evaluated alternative ultrasound velocity criteria for >70% ISR in our institution.Clinical records of 256 patients undergoing 282 consecutive CAS procedures over a 42-month period were reviewed. Follow-up ultrasounds were available for analysis in 237 patients. Selective angiograms and repeat interventions were performed for >70% ISR. Ultrasound criteria including peak systolic velocity (PSV), end diastolic velocity (EDV), and internal carotid to common carotid artery ratios (ICA/CCA) were examined. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for PSV (200, 250, 300, 350, and 400 cm/s), EDV (70, 80, 90, 100 cm/s), and CCA/ICA (3, 3.5, 4, 4.5, 5).Twenty-two carotid angiograms were performed and 18 lesions had confirmations of >70% ISR in 11 patients including prior CEA in five patients and neck irradiation in two patients. Receiver operator characteristics (ROC) was analyzed for PSV, EDV, and CCA/ICA ratio. For 70% or greater angiographic ISR, PSV > 300 cm/s correlated to a 94% sensitivity, 50% specificity, 90% positive predictive value (PPV), and 67% negative predictive value (NPV); EDV > 90 cm/s correlated to an 89% sensitivity, 100% specificity, 100% PPV, and 67% NPV; and ICA/CCA > 4 had a 94.4% sensitivity, 75% specificity, 94% PPV, and 75% NPV. A significant color flow disturbance was detected in one patient who did not meet the aforementioned ultrasound velocity criteria. Further statistical analysis showed that an EDV of 90 cm/s provided the best discriminant value.Our study demonstrated that PSV > 300 cm/s, EDV > 90 cm/s, and ICA/CCA > 4 correlated well with >70% ISR. Although still rudimentary, these velocity criteria combined with color flow patterns can reliably predict severe ISR in our vascular laboratory. However, due to the relatively infrequent cases of severe ISR following CAS, a multicentered study is warranted to establish standard post-CAS ultrasound surveillance criteria for severe ISR.

    View details for DOI 10.1016/j.jvs.2007.09.031

    View details for Web of Science ID 000252124100014

    View details for PubMedID 18178456

  • Dual guidewire placement to enhance arch vessel origin identification: A simple technique to facilitate ostial aortic arch vessel stenting JOURNAL OF VASCULAR SURGERY Hedayati, N., Kougias, P., El Sayed, H. F., Zhou, W., Huynh, T. T., Lin, P. H. 2007; 46 (6): 1274-1276

    Abstract

    Orificial occlusive lesion involving the aortic arch vessels is commonly treated with balloon-expandable stent placement. Stenting of such a lesion typically involves an initial aortogram to precisely identify the vessel origin, followed by deployment of a balloon-expandable stent to cover the ostial lesion. We report a simple technique of an antegrade femoral guidewire placement along the outer curvature of the aortic arch to facilitate the identification of the origin of aortic arch vessels. This enhanced ostial visualization enables a precise positioning and deployment of a balloon-expandable stent in aortic arch vessels. This dual guidewire technique facilitates the visual identification of arch vessel origin and reduces potential contrast requirement, which provides procedural benefit in patients with renal insufficiency or contrast allergy.

    View details for DOI 10.1016/j.jvs.2007.07.019

    View details for Web of Science ID 000251649500028

    View details for PubMedID 18155005

  • Percutaneous cholecystostomy for acute cholecystitis in high-risk patients: experience of a surgeon-initiated interventional program AMERICAN JOURNAL OF SURGERY Silberfein, E. J., Zhou, W., Kougias, P., El Sayed, H. F., Huynh, T. T., Albo, D., Berger, D. H., Brunicardi, C., Lin, P. H. 2007; 194 (5): 672-677

    Abstract

    The treatment of choice for acute cholecystitis is cholecystectomy. However, percutaneous cholecystostomy (PC) is an alternative treatment in patients who are at high risk for urgent surgery. This study reviews our experience of PC for treatment of acute cholecystitis in a surgeon-initiated interventional program.Clinical records of all high-risk patients who underwent PC placement by surgeons (group A; n = 22) for acute cholecystitis were reviewed. Treatment outcomes were compared with patients who underwent PC by interventional radiologists (group B; n = 26).Similar technical success, procedural complication, or treatment outcome were noted between the two groups. Seven patients (32%) in group A and 9 patients (35%) in group B underwent delayed elective cholecystectomy surgery. The time elapsed between the diagnosis to PC placement in groups A and B was 6.6 +/- 3.5 hours and 18.5 +/- 4.3 hours, respectively (P < .02).Ultrasound-guided PC is a safe and effective treatment for acute cholecystitis in high-risk surgical patients. Surgeons with endovascular skills can obtain clinical competence in this catheter-based procedure, which provides an added armamentarium in surgical biliary disease management.

    View details for DOI 10.1016/j.amjsurg.2007.07.019

    View details for Web of Science ID 000250358900018

    View details for PubMedID 17936433

  • Traumatic carotid artery dissection caused by bungee jumping JOURNAL OF VASCULAR SURGERY Zhou, W., Huynh, T. T., Kougias, P., El Sayed, H. F., Lin, P. H. 2007; 46 (5): 1044-1046

    Abstract

    Bungee jumping is a popular recreational activity in which participant experiences transient freefall while connected to a bungee cord. The rapid freefall and the resultant rebound force created by the bungee cord can result in a variety of bodily injuries. We report herein a case of traumatic carotid artery dissection caused by bungee jumping. The symptoms related to carotid artery dissection were successfully treated with anticoagulation. The etiology of carotid dissection related to bungee jumping is discussed. Physicians should be cognizant of this potential injury due to the force created by the freefall and rebound motion associated in this recreational sport.

    View details for DOI 10.1016/j.jvs.2007.06.026

    View details for Web of Science ID 000250675700030

    View details for PubMedID 17980290

  • Factors associated with hypotension and bradycardia after carotid angioplasty and stenting JOURNAL OF VASCULAR SURGERY Lin, P. H., Zhou, W., Kougias, P., El Sayed, H. F., Barshes, N. R., Huynh, T. T. 2007; 46 (5): 846-854

    Abstract

    Acute procedurally induced hemodynamic depression can occur after carotid angioplasty and stenting (CAS). This study was performed to determine the frequency and risk factors for hypotension and bradycardia after the CAS procedure.The study reviewed clinical variables and angiographic data of all patients undergoing elective CAS with neuroprotection during a recent 5-year period. Intravenous atropine was given selectively in cases of bradycardia (heart rate <60 beats/min or a decrease of >20 beats/min). We further defined hemodynamic depression as bradycardia or severe hypotension (systolic blood pressure fall >30 mm Hg). Frequency and potential risk factors for hemodynamic depression were analyzed by logistic regression.During the study period, 416 patients (99% male; mean age, 74 +/- 11 years) underwent the CAS procedure. The median degree of stenosis was 93% (range, 60% to 99%). The frequencies of post-CAS hemodynamic depression include hypotension in 58 (14%), bradycardia in 112 (27%), or both in 21 (5%). All patients with bradycardia received intraprocedural atropine, and all heart rates returned to the baseline level. Persistent hypotension occurred in 45 patients (11%). Increased age was associated with CAS-induced bradycardia or hypotension. Adjusted risk factors associated with hemodynamic depression include age >78 years (odds ratio [OR], 5.25; 95% confidence interval [CI], 2.32 to 15.25; P = .01) and ejection fraction of <25% (OR, 3.25; 95% CI, 0.58 to 6.58; P = .02). CEA-related restenosis was associated with a reduced risk of hemodynamic depression (OR, 0.21; 95% CI, 0.12 to 0.69, P = .001). Persistent hypotension after CAS was associated with an increased risk of an adverse clinical event (44%, P = .001).Hemodynamic depression, including hypotension and bradycardia, is frequent after CAS. However, CAS-induced hemodynamic depression is rare in patients with postendarterectomy stenosis. Patients with compromised ejection fraction and increased age are at a higher risk of presenting with CAS-induced hemodynamic instability, and persistent hypotension after CAS is associated with an increased postprocedural complication rate.

    View details for DOI 10.1016/j.jvs.2007.07.020

    View details for Web of Science ID 000250675700003

    View details for PubMedID 17980268

  • Determinants of mortality and treatment outcome following surgical interventions for acute mesenteric ischemia JOURNAL OF VASCULAR SURGERY Kougias, P., Lau, D., El Sayed, H. F., Zhou, W., Huynh, T. T., Lin, P. H. 2007; 46 (3): 467-474

    Abstract

    Acute mesenteric ischemia (AMI) is associated with high morbidity and mortality due in part to its diagnostic difficulty and operative challenges. The purpose of this study was to review our experience of surgical management in patients with this condition and to identify variables associated with adverse outcomes following surgical interventions.Hospital records and clinical data of all patients undergoing surgical interventions for AMI were reviewed during a recent 12-year period. Clinical outcomes as well as factors influencing mortality were analyzed.A total of 72 patients (41 females, overall mean age 65 years, range 34 to 83 years) were included in the study. Thrombosis and embolism were the cause of AMI in 48 patients (67%) and 24 patients (33%), respectively. Abdominal pain was the most common presenting symptom (96%), followed by nausea (56%). Preoperative angiogram was performed in 61 patients (85%). All patients underwent operative interventions, which included thromboembolectomy (n = 22, 31%), mesenteric bypass grafting (n = 33, 46%), patch angioplasty (n = 9, 12%), reimplantation (n = 5, 7%), and endarterectomy (n = 3, 4%). Bowel resection was necessary in 22 patients (31%) during the initial operation, and second-look operation was performed in 38 patients (53%). Perioperative morbidity and 30-day mortality rates were 39% and 31%, respectively. Univariate analysis showed renal insufficiency (P < .02), age >70 (P < .001), metabolic acidosis (P < .02), and symptom duration (P < .005), and bowel resection in second-look operations (P < .01) were associated with mortality. Logistic regression analysis showed age >70 (P = .03) and prolonged symptom duration (P = .02) were independent predictors of mortality.Elderly patients and those with a prolonged duration of symptoms had worse outcomes following surgical intervention for AMI. A high index of suspicion with prompt diagnostic evaluation may reduce time delay prior to surgical intervention, which may lead to improved patient survival. Aggressive surgical intervention should be performed as promptly as possible in patients once the diagnosis of AMI is made.

    View details for DOI 10.1016/j.jvs.2007.04.045

    View details for Web of Science ID 000249315500014

    View details for PubMedID 17681712

  • Acute aortic dissection associated with use of cocaine JOURNAL OF VASCULAR SURGERY Daniel, J. C., Huynh, T. T., Zhou, W., Kougias, P., El Sayed, H. F., Huh, J., Coselli, J. S., Lin, P. H. 2007; 46 (3): 427-433

    Abstract

    Cocaine use can result in a variety of cardiovascular complications, including myocardial infarction, arterial thrombosis, coronary dissection, and cardiomyopathy. Cocaine-induced aortic dissection is uncommon and has been described largely in case reports. The purpose of this study was to review our experience with aortic dissection associated with cocaine abuse.A retrospective chart review was performed of all hospital records during a 15-year period in patients diagnosed with aortic dissection. Among the 164 cases of acute aortic dissection, 16 patients (9.8%) had used cocaine or its derivative, crack cocaine, within 24 hours prior to the onset of symptoms. The remaining 148 patients (90.2%) had no history of cocaine usage. Clinical features, management, and outcome in these two groups were compared.In the cocaine group, powder cocaine was inhaled intranasally in 11 patients (69%) and crack cocaine was smoked in five cases (31%). The mean duration between cocaine use and the onset of aortic dissection was 12.8 hours (range, 4 to 24 hours). Patients in the cocaine group were younger in age and more likely to have a history of polysubstance abuse than the non-cocaine cohort. In the cocaine group, the incidence of DeBakey dissection type I, II, IIIa, and IIIb was 19%, 25%, 38%, and 19%, respectively. In the group without cocaine use, the incidence of DeBakey dissection type I, II, IIIa, and IIIb was 18%, 23%, 39%, and 20%, respectively. Surgical intervention for aortic dissection was performed in 50% of the cocaine group and 45% of the non-cocaine group. In patients who underwent surgical repair, greater pulmonary complications occurred in the cocaine group than the non-cocaine group (n = 0.02). No difference was noted in the hospital length of stay or 30-day operative mortality among the two groups.Cocaine-associated aortic dissection occurs in predominantly male patients with illicit drug abuse who were younger than patients with aortic dissection without cocaine use. Greater pulmonary complications can occur in patients with cocaine-related aortic dissection following surgical interventions.

    View details for DOI 10.1016/j.jvs.2007.05.040

    View details for Web of Science ID 000249315500005

    View details for PubMedID 17826227

  • Successful treatment of endotension and aneurysm sac enlargement with endovascular stent graft reinforcement JOURNAL OF VASCULAR SURGERY Kougias, P., Lin, P. H., Dardik, A., Lee, W. A., El Sayed, H. F., Zhou, W. 2007; 46 (1): 124-127

    Abstract

    Abdominal aortic aneurysm (AAA) enlarges after successful endovascular repair because of endoleak, which is persistent blood flow within the aneurysm sac. In the absence of detectable endoleak, AAA may still expand, in part because of endotension, which is persistent pressurization within the excluded aneurysm. We report three patients who underwent successful endovascular AAA repair using the Excluder device (W. L. Gore & Associates, Flagstaff, Ariz). Although their postoperative surveillance showed an initial aneurysm regression, delayed aneurysm enlargement developed in all three, apparently due to endotension. Endovascular treatment was performed in which endograft reinforcement with a combination of aortic cuff and iliac endograft extenders were inserted in the previously implanted stent grafts. The endograft reinforcement procedure successfully resulted in aneurysm sac regression in all three patients. Our study underscores the significance of increased graft permeability as a mechanism of endotension and delayed aneurysm enlargement after successful endovascular AAA repair. In addition, our cases illustrate the feasibility and efficacy of an endovascular treatment strategy when endotension and aneurysm sac enlargement develops after endovascular AAA repair.

    View details for DOI 10.1016/j.jvs.2007.02.067

    View details for Web of Science ID 000247707500021

    View details for PubMedID 17606128

  • Endovascular repair of thoracic aortic disease: Overview of current devices and clinical results VASCULAR Lin, P. H., El Sayed, H. F., Kougias, P., Zhou, W., LeMaire, S. A., Coselli, J. S. 2007; 15 (4): 179-190

    Abstract

    Endovascular repair of thoracic aortic aneurysm has become an important treatment modality in patients who are at increased risk for open surgical repair. Since the US Food and Drug Administration (FDA) approved the clinical application of this technology in the thoracic aorta in 2005, there has been a rapid growth in this treatment modality as numerous endovascular devices have been introduced in the application of thoracic aortic pathology. Although thoracic aortic aneurysm is the only FDA-approved treatment indication for endovascular repair, this technology may lead to a broader clinical applicability in other thoracic pathologies. This article reviews the current endovascular devices designed for the treatment of thoracic aortic pathology. These devices are described, and the current clinical results are discussed.

    View details for DOI 10.2310/6670.2007.00041

    View details for Web of Science ID 000249669000001

    View details for PubMedID 17714632

  • Management of chronic mesenteric ischemia. The role of endovascular therapy JOURNAL OF ENDOVASCULAR THERAPY Kougias, P., El Sayed, H. F., Zhou, W., Lin, P. H. 2007; 14 (3): 395-405

    Abstract

    Chronic mesenteric ischemia is an uncommon disorder manifested most commonly as abdominal pain. Surgical revascularization has traditionally been the treatment of choice. Endovascular management of this entity was originally attempted as an alternative for high-risk patients. Improvements in stent technology, refinement in technique, and increased efficiency of antiplatelet regimens have, over time, increased the popularity of this minimally invasive approach. We present a review of the available series on endovascular treatment of chronic mesenteric ischemia, with emphasis on short- and long-term outcome and morbidity and mortality results. Principles of operative technique and controversial issues and topics of interest are also discussed.

    View details for Web of Science ID 000247919700018

    View details for PubMedID 17723025

  • Concomitant intraoperative splenic artery embolization and laparoscopic splenectomy versus laparoscopic splenectomy: comparison of treatment outcome AMERICAN JOURNAL OF SURGERY Naoum, J. J., Silberfein, E. J., Zhou, W., Sweeney, J. F., Albo, D., Brunicardi, F. C., Kougias, P., El Sayed, H. F., Lin, P. H. 2007; 193 (6): 713-718

    Abstract

    Although laparoscopic splenectomy has become the preferred treatment of choice for hematologic-related splenic disorders, intraoperative blood loss remains a common occurrence. In an effort to reduce this risk, we evaluate the potential role and clinical outcome of concomitant intraoperative splenic artery embolization and laparoscopic splenectomy.Between June 2000 and July 2005, 18 patients with hematologically related splenic disorders underwent combined intraoperative splenic artery embolization and laparoscopic splenectomy (group 1). For comparison, we studied 18 age- and gender-matched case controls undergoing same operations during the same period (group 2). Intraoperative data and clinical outcome were compared between the 2 groups.Technical success was 100% in group 1. One patient in group 2 was converted to open splenectomy because of severe blood loss, resulting in a technical success rate of 95%. The mean splenic size in group 1 and group 2 was 15.5 +/- 4.7 cm (range, 12-23 cm) and 15.7 +/- 6.8 (range, 11-24 cm), respectively (not significant [NS]). Mean operative time in group 1 and group 2 was 175 minutes and 162 minutes, respectively (NS). Significantly less intraoperative blood loss was noted in group 1 (mean, 25 mL; range, 15-63 mL) compared with group 2 (mean, 240 mL; range, 150-420 mL; P < .003). There was an even greater difference in blood loss between the 2 groups when the splenic size was greater than 18 cm (mean 35 mL in group 1 versus 350 mL in group 2, P < .001). No differences were noted in postoperative recovery, return of bowel function, or length of hospital stay between the 2 groups.Concomitant splenic artery embolization and laparoscopic splenic reduced operative blood loss when compared with laparoscopic splenectomy procedure alone. Splenic artery embolization is a useful intraoperative adjunctive procedure that should be considered in patients undergoing laparoscopic splenectomy for hematologic disorders who are Jehovah's Witness or with significant hypersplenism because of benefit of reduced blood loss.

    View details for DOI 10.1016/j.amjsurg.2006.09.043

    View details for Web of Science ID 000246831400012

    View details for PubMedID 17512282

  • Multiple giant anastomotic pseudoaneurysms of the carotid and femoral arteries: Combined endovascular and open surgical approach VASCULAR Guerrero, M. A., Zhou, W., Kougias, P., El Sayed, H., Lin, P. H. 2007; 15 (3): 158-161

    Abstract

    Anastomotic pseudoaneurysm is a known complication following carotid artery endarterectomy and aortobifemoral bypass surgeries. However, giant concurrent carotid and femoral artery anastomotic pseudoaneurysms are rare. We herein report a case of successful treatment of multiple giant anastomotic pseudoaneurysms using a combined endovascular and surgical approach. Our case highlights the fact that endovascular techniques can facilitate open surgical repair of complex anastomotic pseudoaneurysms.

    View details for DOI 10.2310/6670.2007.00029

    View details for Web of Science ID 000250654300007

    View details for PubMedID 17573022

  • Peripheral arterial occlusive disease: Magnetic resonance imaging and the role of aggressive medical management WORLD JOURNAL OF SURGERY Lumsden, A. B., Rice, T. W., Chen, C., Zhou, W., Lin, P. H., Bray, P., Morrisett, J., Nambi, V., Ballantyne, C. 2007; 31 (4): 695-704

    Abstract

    Atherosclerosis accounts for most peripheral arterial occlusive disease (PAD). Although many of the risk factors for atherosclerotic coronary artery disease (CAD) such as hyperlipidemia have been identified as risk factors for peripheral arterial disease, strong evidence is lacking that risk factor modification is effective in halting progression or improving outcomes. A better understanding is needed regarding the clinical and pathophysiologic responses to risk factor modification. This review describes current advances in the medical management for PAD including lipid modification antiplatelet therapy, angiotensin-converting enzyme (ACE) inhibitors, beta-blockers, exercise, and endovascular intervention. In addition, we discuss our active ELIMIT Trial (Effect of Lipid Modification on Peripheral Arterial Disease after Endovascular Intervention). We test the hypothesis that an aggressive regimen of serum lipid modification will inhibit the progression of atherosclerosis in femoral arteries and reduce the incidence of restenosis of femoral arteries following endovascular stenting by decreasing thrombosis and inflammation. This study will provide a novel strategy for retarding or preventing progression of atherosclerosis and re-stenosis of peripheral arterial disease following arterial revascularization procedures. Importantly, our magnetic resonance imaging studies will provide quantitative data on the vascular lesions in PAD. These studies will advance our understanding of the molecular mechanisms of inflammation and thrombosis associated with aggressive lipid modification.

    View details for DOI 10.1007/s00268-006-0732-y

    View details for Web of Science ID 000245237300012

    View details for PubMedID 17345122

  • Prevention and treatment of aortic graft infection EXPERT REVIEW OF ANTI-INFECTIVE THERAPY Mussa, F. F., Hedayati, N., Zhou, W., El-Sayed, H. F., Kougias, P., Darouiche, R. O., Lin, P. H. 2007; 5 (2): 305-315

    Abstract

    Prosthetic vascular graft infection remains one of the most challenging surgical problems for vascular surgeons. This condition is classically associated with high morbidity and mortality rates. Accurate diagnosis of a vascular graft infection can typically be made based on a thorough history and physical examination; although, infrequently, an extensive radiological evaluation is necessary to establish the clinical finding. Complete graft excision and extra-anatomic bypass grafting remains a commonly accepted surgical treatment strategy. Recent clinical data have supported other treatment modalities, including the use of in situ antibiotic-impregnated graft replacement, in situ allograft replacement and in situ autologous graft replacement. This article will review the pathobiology of aortic graft infection, as well as methods to prevent a prosthetic graft infection. Furthermore, various surgical treatment modalities of aortic graft infection will be discussed.

    View details for DOI 10.1586/14787210.5.2.305

    View details for Web of Science ID 000250568300023

    View details for PubMedID 17402845

  • Rheolytic pharmacomechanical thrombectomy in experimental chronic deep vein thrombosis: Effect of L-arginine on thrombogenicity and endothelial vasomotor function WORLD JOURNAL OF SURGERY Lin, P. H., Okada, T., Steinberg, J. L., Zhou, W., El Sayed, H. F., Rawat, A., Kougias, P., Yao, Q., Chen, C. 2007; 31 (4): 664-675

    Abstract

    Endovascular removal of intravascular thrombus using the AngioJet rheolytic thrombectomy (RT) system has been shown to be clinically effective. This system also permits the concomitant infusion of thrombolytic agent followed by thrombectomy, thus creating a novel strategy known as pharmacomechanical thrombectomy (PMT). Although these interventions have gained wide clinical application, little is known regarding the vessel wall response following thrombectomy therapy. The aims of this study were to assess the effect of thrombectomy interventions on endothelial function in a porcine model of deep venous thrombosis (DVT) and to evaluate the effect of nitric oxide (NO) precursor L-arginine on endothelial function following thrombectomy therapy.Deep vein thrombosis was created in bilateral iliac veins by deploying a self-expanding stent-graft incorporating an intraluminal stenosis from a groin approach. Five pigs underwent sham operation. Following 14 days of DVT, animals were randomized to three groups: the first group received RT treatment (RT group, n = 5); the second group received pharmacomechanical thrombectomy (PMT) with tissue plasminogen activator (alteplase 10 mg; PMT group, n = 5); and the third group received PMT with tPA plus intravenous L-arginine (20 mmol/l) (arginine group, n = 5). Iliac vein patency was evaluated by venography and intravascular ultrasound at 1 week. Nitric oxide level was determined by a chemiluminescent assay of the nitrite/nitrate metabolites (NO(x)). Thrombogenicity was evaluated by radiolabeled platelet and fibrin deposition. Veins were harvested and evaluated with light microscopy and scanning electron microscopy (SEM). Endothelial function was evaluated using organ chamber analysis.The luminal areas in the sham, RT, PMT, and arginine groups were 34 +/- 10 mm(2), 21 +/- 13 mm(2), 35 +/- 18 mm(2), and 37 +/- 16 mm(2), respectively. All iliac veins remained patent at 2 weeks. No difference in endothelial cell structure was observed between the three treatment groups by means of light microscopic or SEM examination. A decrease in platelet deposition occurred in the arginine group compared to the RT and PMT groups (P < 0.05). The arginine group also showed a greater endothelium-dependent relaxation compared to the RT or PMT groups in response to A23187, bradykinin, and ADP (P < 0.05). Local NO(x) level was higher in the arginine group than in the RT or PMT group (2.6 +/- 0.6 micromol/l versus 0.3 +/- 0.1 micromol/l and 0.3 +/- 0.2 micromol/l; P < 0.01).AngioJet RT and PMT interventions resulted in similar attenuated endothelium-dependent vasoreactivity and morphologic effect. L-Arginine supplementation preserves endothelial vasoreactivity and reduces platelet deposition following PMT in iliac DVT. Additionally, L-arginine enhances NO production at sites of venous thrombosis. The NO precursor L-arginine may have a therapeutic potential in preserving endothelial function following mechanical thrombectomy.

    View details for DOI 10.1007/s00268-007-0733-5

    View details for Web of Science ID 000245237300008

    View details for PubMedID 17308845

  • Comparison of AngioJet rheolytic pharmacomechanical thrombectomy versus AngioJet rheolytic thrombectomy in a porcine peripheral arterial model WORLD JOURNAL OF SURGERY Lin, P. H., Mussa, F. F., Hedayati, N., Naoum, J. J., Zhou, W., Yao, Q., Kougias, P., El Sayed, H. F., Chen, C. 2007; 31 (4): 715-722

    Abstract

    Rheolytic thrombectomy using the AngioJet catheter for arterial thrombosis has been shown to be effective in restoring blood flow. Additional infusion of thrombolytic agents via the AngioJet catheter results in combined rheolytic pharmacomechanical thrombolysis (PMT), which further enhances thrombectomy efficacy. However, the histologic response to rheolytic PMT therapy remains unclear. This study compares the acute and chronic vessel wall response and hemolysis due to conventional AngioJet rheolytic thrombectomy (RT) and AngioJet PMT in the porcine peripheral arterial model.A total of 19 juvenile pigs were divided into acute and chronic groups. In the acute group (n = 6), bilateral common carotid, femoral, and iliac arteries ranging from 3 to 6 mm in diameter were randomized to the control RT group or to PMT therapy. Vessels were analyzed 4 days following interventions. In the chronic group (n = 5), bilateral common carotid, femoral, and iliac arteries ranging from 3 to 6 mm in diameter were randomized to the control RT group or to PMT therapy. Vessels were analyzed at 30 days following interventions. Hemolytic evaluation was performed in additional eight pigs, which were randomized to either RT or PMT intervention.In the acute group, similar histologic injury grades were noted between the RT- and PMT-treated femoral and iliac vessels. Endothelial denudation in the RT and PMT vessels were 43% and 39% (NS), respectively. Vessels with intact internal elastic lamina (IEL) in the RT and PMT groups were 54% and 57% (NS), respectively. In vessels < 4 mm in diameter, fractured IEL in the AT and PMT groups occurred in 23% and 27% (NS), respectively. The degrees of smooth muscle cell (SMC) loss were similar for the RT- and PMT-treated vessels (45% and 40%, respectively; NS). In the chronic group, no differences were seen between the RT and PMT groups with respect to endothelial denudation, IEL fracture rate, or SMC loss. Similar degrees of medial thickening or intimal hyperplasia were noted in the RT and PMT groups (49% and 43%, respectively; NS). No difference in hemolytic effect was noted in the treatment groups.AngioJet rheolytic pharmacomechanical thrombectomy treatment incurs an equivalent safety profile in medium-caliber peripheral arteries when compared to rheolytic thrombectomy treatment. No difference in hemolytic reaction occurred in either group. The observed clinical efficacy of rheolytic pharmacomechanical thrombectomy does not result in untoward vessel injury compared to conventional rheolytic thrombectomy therapy.

    View details for DOI 10.1007/s00268-006-0734-9

    View details for Web of Science ID 000245237300014

    View details for PubMedID 17345121

  • Iliac vein stenting for chronic venous insufficiency TEXAS HEART INSTITUTE JOURNAL Mussa, F. F., Peden, E. K., Zhou, W., Lin, P. H., Lumsden, A. B., Bush, R. L. 2007; 34 (1): 60-66

    Abstract

    Chronic venous insufficiency has devastating sequelae in terms of patients' lifestyles and negative economic impact on society. Traditional surgical procedures have yielded variable patency results, and follow-up has not always been reported. This review summarizes the current applications, patency rates, stent selection, and complications of balloon angioplasty and stenting in the treatment of chronic venous outflow obstruction in the lower extremity. We conclude that endovenous stenting is the current method of choice in the treatment of chronic venous obstruction.

    View details for Web of Science ID 000245344000014

    View details for PubMedID 17420795

  • Percutaneous transhepatic thrombectomy and pharmacologic thrombolysis of mesenteric venous thrombosis VASCULAR Zhou, W., Choi, L., Lin, P. H., Dardik, A., Eraso, A., Lumsden, A. B. 2007; 15 (1): 41-45

    Abstract

    Mesenteric venous occlusion is a rare yet highly morbid condition that is traditionally treated with anticoagulation while surgery serves as the last resort. Percutaneous intervention provides an effective option with relatively low mortality and morbidity. We herein describe use of transhepatic percutaneous thrombectomy and pharmacologic thrombolysis in treating two cases of symptomatic mesenteric venous thrombosis. These cases underscore the fact that transhepatic thrombectomy and thrombolysis are a highly effective strategy for treating acute symptomatic mesenteric venous thrombosis. Several percutaneous techniques are also reviewed.

    View details for DOI 10.2310/6670.2007.00013

    View details for Web of Science ID 000248141900009

    View details for PubMedID 17382054

  • Catheter-direct thrombolysis versus pharmacomechanical thrombectomy for treatment of symptomatic lower extremity deep venous thrombosis AMERICAN JOURNAL OF SURGERY Lin, P. H., Zhou, W., Dardik, A., Mussa, F., Kougias, P., Hedayati, N., Naoum, J. J., El Sayed, H., Peden, E. K., Huynh, T. T. 2006; 192 (6): 782-788

    Abstract

    Rheolytic mechanical thrombectomy using the AngioJet catheter (Possis Medical, Minneapolis, MN) has been shown to be effective in the treatment of deep venous thrombosis (DVT). Additional infusion of thrombolytic agents via the device creates a novel treatment strategy of pharmacomechanical thrombectomy (PMT), which further enhances thrombectomy efficacy. The purpose of the current study was to compare the treatment outcome in patients with symptomatic DVT who underwent either catheter-directed thrombolysis (CDT) or PMT intervention.During a recent 8-year period, clinical records of all patients with symptomatic lower leg DVT undergoing catheter-directed interventions were evaluated. Patients were divided into 2 treatment groups: CDT or PMT. Comparisons were made with regards to the treatment outcome between the 2 groups.A total of 93 patients who underwent 98 catheter-directed interventions for DVT were included in the study. Among them, CDT or PMT was performed in 46 (47%) and 52 (53%) procedures, respectively. In the CDT group, complete or partial thrombus removal was accomplished in 32 (70%) and 14 (30%) cases, respectively. In the PMT cohort, complete or partial thrombus removal was accomplished in 39 (75%) and 13 (25%) cases, respectively. Venous balloon angioplasty and/or stenting in the CDT or PMT groups was necessary in 36 (78%) and 43 (82%), respectively (difference not significant [NS]). Patients in the CDT groups underwent a mean of 2.5 venograms during the hospital course, in contrast to 0.4 venograms per patient in PMT cohorts (P < .001). Immediate (<24 hours) improvement in clinical symptoms in CDT and PMT groups was achieved in 33 (72%) and 42 (81%) cases, respectively (NS). Significant reductions in the intensive care unit (ICU) and hospital lengths of stay was noted in the PMT group (0.6 and 4.6 days) when compared to the CDT group (2.4 and 8.4 days). During follow-up visits, the primary patency rates at 1 year of CDT and PMT groups were 64% and 68%, respectively (NS). Hospital cost analysis showed significant cost reduction in the PMT group compared to the CDT group (P < .01).PMT with adjunctive thrombolytic therapy is an effective treatment modality in patients with significant DVT. When compared to CDT, this treatment provides similar treatment success with reduced ICU, total hospital length of stay, and hospital costs.

    View details for DOI 10.1016/j.amjsurg.2006.08.045

    View details for Web of Science ID 000242928400030

    View details for PubMedID 17161094

  • Chronically impaired endothelial vasoreactivity following oversized endovascular introducer sheath placement in porcine iliac arteries: Implications for endovascular therapy VASCULAR Lin, P. H., Steinberg, J. L., Okada, T., Zhou, W., El Sayed, H. F., Kouglas, P., Peden, E. K., Huynh, T. T., Yao, Q., Chen, C. 2006; 14 (6): 353-361

    Abstract

    The conventional endovascular aortic aneurysm procedure entails the placement of oversized introducer sheaths in relatively normal ileofemoral arteries to allow the delivery and deployment of endovascular prosthesis. Endoluminal manipulation with passage of oversized endoluminal devices can lead to endothelial denudation, resulting in impaired cellular function. The purpose of this study was to assess the time course of endothelial function with vasoreactivity following oversized endovascular sheath insertion ranging from 1 day to 16 weeks in normal porcine iliac arteries. Following oversized introducer sheath placement in bilateral iliac arteries, vasoreactivity was tested using both endothelium-dependent and -independent vasodilators. Intravascular ultrasonography showed a significant reduction in the luminal area at 12 and 16 weeks. This was similarly supported by morphometric analysis, which showed increased medial thickness with an elevated intima to media ratio at the same time course. Endothelium-dependent relaxation to bradykinin, calcium ionophore A23187, serotonin, and adenosine diphosphate all uniformly displayed attenuated endothelial dysfunction at all time points when compared with the control group. In contrast, endothelium-independent relaxation showed a decreased vasoresponsiveness at 4 weeks. In conclusion, this study underscored the detrimental and chronic endothelial dysfunction in a normal artery caused by oversized introducer sheath placement. Chronically impaired endothelial function may play a role leading to iliofemoral artery thrombosis or late occlusion, which were well-recognized adverse events following endovascular aneurysm procedures. Our study underscores the importance of appropriate patient selection to minimize potential sheath oversize and endograft device miniaturization to avoid vessel wall injury and maintain vasoreactivity.

    View details for DOI 10.2310/6670.2006.00060

    View details for Web of Science ID 000202989900006

    View details for PubMedID 17150156

  • Hybrid approach to complex thoracic aortic aneurysms in high-risk patients: Surgical challenges and clinical outcomes JOURNAL OF VASCULAR SURGERY Zhou, W., Reardon, M., Peden, E. K., Lin, P. H., Lumsden, A. B. 2006; 44 (4): 688-693

    Abstract

    Endovascular therapy is a less invasive alternative treatment for high-risk patients with thoracic aortic aneurysms. However, this technology alone is often not applicable to complex aneurysmal morphology. The purpose of this study was to evaluate the utility of hybrid strategies in high-risk patients who are otherwise unsuitable for endovascular therapy alone.During an 18-month period, 31 high-risk patients (mean age, 69 years; range, 52-89 years) underwent combined open and endovascular approaches for complex aneurysms, including 16 patients with ascending and arch aneurysms and 15 patients with aneurysms involving visceral vessels. Among them, 11 patients had histories of aneurysm repairs. To overcome the anatomic limitations of endovascular repairs, various adjunctive surgical maneuvers were used, including aortic arch reconstruction in 3 patients, supra-aortic trunk debranching in 13 patients (including 8 patients who required aortas as inflow sources), and visceral vessel bypasses in 15 patients (including 10 patients who required bypasses to all 3 visceral branches). Additionally, carotid artery access was obtained in 1 patient, and iliac artery conduits were created in 12 patients.Technical success was achieved in all patients. There was one perioperative death (3.2%) due to postoperative bleeding. Two patients (6.4%) had immediate type II endoleaks, which were resolved by the 1-month follow-up. Other procedure-related complications occurred in three patients (9.6%), including renal bypass thromboses in two patients and retroperitoneal hematoma, which was successfully managed conservatively, in one patient. During a mean follow-up of 16 months, two patients died of unrelated causes, whereas the remainder of patients were asymptomatic, without aneurysm enlargement.Our study highlights how hybrid strategies incorporating surgical and endovascular approaches can be used successfully in treating patients with complex thoracic aortic aneurysms. This combined approach potentially expands the field of endovascular stent grafting and is an attractive solution for patients with poor cardiopulmonary reserves.

    View details for DOI 10.1016/j.jvs.2006.06.013

    View details for Web of Science ID 000240960000001

    View details for PubMedID 16926086

  • Ginkgolide A attenuates homocysteine-induced endothelial dysfunction in porcine coronary arteries JOURNAL OF VASCULAR SURGERY Zhou, W., Chai, H., Courson, A., Lin, P. H., Lumsden, A. B., Yao, Q., Chen, C. 2006; 44 (4): 853-862

    Abstract

    Homocysteine is an independent risk factor for atherosclerosis. The objective of this study was to investigate whether ginkgolide A (GA), a major constituent of Ginkgo biloba, could block homocysteine-induced endothelial dysfunction in porcine coronary arteries.Porcine coronary artery rings were assigned to six treatment groups: control; homocysteine (50 micromol/L); low-dose (50 micromol/L) or high-dose (100 micromol/L) GA; and homocysteine plus low-dose or high-dose GA. After 24 hours' incubation, the rings were analyzed for vasomotor function in response to a thromboxane A2 analogue (U46619), bradykinin, and sodium nitroprusside. Endothelial nitric oxide synthase (eNOS) was studied by using real-time polymerase chain reaction and immunohistochemistry analysis. Superoxide anion production was assessed by chemoluminescence analysis.Endothelium-dependent relaxation (bradykinin) was significantly reduced in ring segments treated with homocysteine as compared with the control (P < .05). When homocysteine was combined with either low-dose or high-dose GA, endothelium-dependent relaxation was markedly recovered. There was no significant difference in maximal contraction (U46619) or endothelium-independent relaxation (sodium nitroprusside) among all groups. In addition, superoxide anion production was increased by 113% in the homocysteine-treated group, whereas there was no statistically significant difference between the control and GA/homocysteine groups. Furthermore, eNOS messenger RNA and protein levels were substantially reduced in the homocysteine-treated group (P < .05), but not in the GA/homocysteine combined groups.Homocysteine significantly impairs endothelium-dependent vasorelaxation through oxidative stress and downregulation of eNOS in porcine coronary arteries. GA effectively prevents homocysteine-induced endothelial dysfunction and molecular changes in porcine coronary arteries. This study underscores the potential clinical benefits and applications of GA in controlling homocysteine-associated vascular injury and cardiovascular disease.Homocysteine is an independent risk factor for atherosclerosis. This study showed that ginkgolide A, a major constituent of Ginkgo biloba, effectively prevents homocysteine-induced endothelial dysfunction and molecular changes in porcine coronary arteries. This study underscores potential clinical benefits and applications of ginkgolide A in controlling homocysteine-associated vascular injury and cardiovascular disease.

    View details for DOI 10.1016/j.jvs.2006.06.012

    View details for Web of Science ID 000240960000030

    View details for PubMedID 17012008

  • Utility of retrievable vena cava filters and mechanical thrombectomy in the endovascular management of acute deep venous thrombosis VASCULAR El Sayed, H. F., Kougias, P., Zhou, W., Lin, P. H. 2006; 14 (5): 305-312

    Abstract

    Endovascular interventions of symptomatic deep venous thrombosis (DVT) using various therapeutic modalities, such as thrombolysis, mechanical thrombectomy, and inferior vena cava (IVC) filter placement, have received increased focus owing in part to advances in catheter-based interventional technologies. Although systemic anticoagulation remains the primary treatment modality in DVT, catheter-based interventions can provide rapid removal of large thrombus burden and possibly preserve venous valvular function in patients with symptomatic DVT. This article reviews current endovascular treatment strategies for acute DVT. Specifically, the utility of mechanical thrombectomy along with various temporary IVC filters in the setting of DVT is examined. Lastly, an illustrative case of acute DVT that was treated with endovascular intervention with IVC filter placement is presented.

    View details for DOI 10.2310/6670.2006.00046

    View details for Web of Science ID 000202989800009

    View details for PubMedID 17038301

  • Carotid artery stenting with distal protection using the carotid wallstent and FilterWire neuroprotection: Single-center experience of 380 cases with midterm outcomes VASCULAR Lin, P. H., Zhou, W., Guerrero, M. A., McCoy, S. A., Felkaz, D., Kougias, P., El Sayed, H. F. 2006; 14 (5): 237-244

    Abstract

    Emerging data have supported the clinical efficacy of carotid artery stenting (CAS) in stroke prevention in high-risk surgical patients. This study was performed to evaluate the midterm clinical outcome of CAS using the Carotid Wallstent and FilterWire distal protection (both Boston Scientific, Natick, MA) at an academic institution. Risk factors for in-stent restenosis (ISR) were also analyzed. Clinical variables and treatment outcome of high-risk patients who underwent Carotid Wallstent placement with FilterWire EX/EZ neuroprotection were analyzed during a recent 54-month period. Three hundred eighty CAS procedures were performed in 354 patients. Technical success was achieved in 372 cases (98%), and symptomatic lesions existed in 85 (24%) patients. No patient experienced periprocedural mortality or neuroprotective device-related complication. The 30-day stroke and death rate was 2.7%, and the overall complication rate was 6.9%. The overall major or fatal stroke rates in symptomatic and asymptomatic patients were 4.6% and 1.3%, respectively (not significant). The overall stroke and death rates between the symptomatic and asymptomatic groups were 5.8% and 2.4%, respectively (not significant). The median follow-up period was 29 months (range 1-53 months). With Kaplan-Meier analysis, the rates of freedom from 60% or greater ISR after CAS procedures at 12, 24, 36, and 48 months were 97%, 94%, 92%, and 90%, respectively. The rates of freedom from all fatal and nonfatal strokes at 12, 24, 36, and 48 months were 97%, 91%, 89%, and 85%, respectively. Multivariable analysis of significant univariate predictors identified that postendarterectomy stenosis (odds ratio [OR] 3.98, p = .02) and multiple stent placement (OR 3.68, p = .03) were independent predictors of ISR. Our study yielded favorable short-term and midterm clinical results using Carotid Wallstent with FilterWire neuroprotection. Late follow-up results showed low rates of fatal and nonfatal stroke and favorable ISR rates compared with other carotid stent trials. Postendarterectomy and multiple stent placement were associated with subsequent ISR.

    View details for DOI 10.2310/6670.2006.00054

    View details for Web of Science ID 000202989800001

    View details for PubMedID 17038293

  • Delayed deformation of self-expanding stents after carotid artery stenting for postendarterectomy rentenoses JOURNAL OF VASCULAR SURGERY Yallampalli, S., Zhou, W., Lin, P. H., Bush, R. L., Lumsden, A. B. 2006; 44 (2): 412-415

    Abstract

    Carotid artery stenting has become an acceptable alternative for treating patients with severe atherosclerotic lesions, particularly those with significant surgical risks, such as recurrent stenosis after endarterectomy. Stent deformation, a phenomenon primarily associated with balloon-expandable stents, is largely avoided by exclusively using self-expanding stents in treating carotid artery stenosis. Nonetheless, we herein report two patients who presented with delayed Wallstent deformation after carotid artery stenting for postendarterectomy restenosis. Our cases highlight the need for caution because delayed deformation of self-expanding stents can occur, particularly during treatment of patients with postendarterectomy stenosis. Furthermore, poststent surveillance is imperative in identifying patients with severe restenosis after carotid artery stenting who need reintervention.

    View details for DOI 10.1016/j.jvs.2006.03.045

    View details for Web of Science ID 000239538400031

    View details for PubMedID 16890879

  • Laser atherectomy for lower extremity revascularization: An adjunctive endovascular treatment option. Vascular and endovascular surgery Zhou, W., Bush, R. L., Lin, P. H., Peden, E. K., Lumsden, A. B. 2006; 40 (4): 268-274

    Abstract

    Excimer laser atherectomy (LA) employs precision laser energy control (shallow tissue penetration) and safer wavelengths (ultraviolet as opposed to the infrared spectra in older laser technology), which decreases perforation and thermal injury to the treated vessels. Though extensively used by cardiologists for severe obstructive coronary artery disease, peripheral interventionalists have not accepted LA as a routine adjunctive technique for stenotic or occluded vessels. We report herein the technical and clinical outcomes with LA for complex peripheral vascular disease in patients deemed high-risk for conventional surgical revascularization. Over a 6-month period, 19 lesions in 15 high-risk patients (mean age 72 +/-10 years) were treated with LA (308-nm spectral wavelength) followed by balloon angioplasty for limb-threatening ischemia (n = 10) and severe disabling claudication (n = 5). The lesions were located at the superficial femoral artery (n = 8), popliteal artery (6), and/or tibial vessels (5). The mean occlusion length was 10.3 +/-2.3 cm. Laser catheter choice ranged from 1.4 to 2.5 mm depending on the target vessel diameter. Clinical examination, duplex ultrasound, and ankle-brachial indices were performed in follow-up visits. Immediate technical success was achieved in 16 (84%) lesions. In the 3 technical failures, inability to cross the lesion with a wire (n = 2) or vessel perforation (n = 1) precluded successful LA. Overall, primary patency as assessed by duplex was 57% (superficial femoral artery 71%, popliteal 60%, tibial vessels 25%). Clinical improvement was seen in 10 lesions (77%) that were successfully treated initially. One patient required below-knee amputation. At an average of 2-year follow-up, 6 patients who were initially successfully treated were alive (46%), including 3 patients (50%) with stable symptoms without the need for major amputation. Laser atherectomy is a useful adjunctive revascularization technique for high-risk patients with limb-threatening ischemia. This technique is especially beneficial in the treatment of ostial lesions, which may be prone to distal embolization, as well as total occlusions that can be traversed by a guide wire but not a balloon. Vascular surgeons should add LA to their endovascular armamentarium for the treatment of complex peripheral vascular disease in the high surgical risk patients. Further study of clinical outcome measures and comparison to other interventional techniques are warranted.

    View details for PubMedID 16959719

  • IMA clipping for a type II endoleak: Combined laparoscopic and endovascular approach SURGICAL LAPAROSCOPY ENDOSCOPY & PERCUTANEOUS TECHNIQUES Zhou, W., Lumsden, A. B., Li, J. 2006; 16 (4): 272-275

    Abstract

    We describe herein a combined laparoscopic and endovascular approach to treat a type II endoleak due to retrograde flow in the patent inferior mesenteric artery (IMA). A 61-year-old gentleman presented with enlarging aneurysm sac confirmed on computed tomography scan evaluation after elective endovascular repair of an infrarenal abdominal aortic aneurysm. A combined laparoscopic and endovascular approach was used. After distal IMA was identified and marked with a clip laparoscopically, on-table angiography showed a proximal left colic branch and persistent flow in the IMA. Therefore, further laparoscopic exploration was performed by dissection along the distal branch. The origin of IMA was then located and subsequently sealed with 2 surgical clips. The completion angiography confirmed the proper position of the surgical clips and absence of endoleak. Our case demonstrated useful role of endovascular techniques in identifying the origin of IMA during laparoscopic approach for treating type II endoleak.

    View details for Web of Science ID 000240186300019

    View details for PubMedID 16921313

  • Endovascular training of vascular surgeons: Have we made progress? SEMINARS IN VASCULAR SURGERY Zhou, W., Lin, P. H., Bush, R. L., Lumsden, A. B. 2006; 19 (2): 122-126

    Abstract

    The rapid evolution of catheter-based technologies during the last 5 years has created a critical need for development of effective resident level and postgraduate education programs in both open and endovascular techniques and associated cognitive and clinical skills. Currently, significant variability exists in endovascular training formats and in the number of endovascular procedures performed during the course of a graduate or postgraduate program. Little information on the quality of these programs exists and in the subsequent practice patterns of the trainees. This report reviews recommended credentialing requirements, training paradigms, and the growing experience of vascular surgical trainees since 2000.

    View details for DOI 10.1053/j.semvascsurg.2006.03.010

    View details for Web of Science ID 000242240200011

    View details for PubMedID 16782519

  • Endovascular repair of a proximal aortic arch aneurysm: A novel approach of supra-aortic debranching with antegrade endograft deployment via an anterior thoracotomy approach JOURNAL OF VASCULAR SURGERY Zhou, W., Reardon, M. E., Peden, E. K., Lin, P. H., Bush, R. L., Lumsden, A. B. 2006; 43 (5): 1045-1048

    Abstract

    Although open surgical repair continues to be the standard therapy for thoracic aortic aneurysms, endovascular intervention has evolved into an acceptable strategy for patients who have prohibitive risks for conventional surgical treatments. Aortic arch aneurysm, in particular, is associated with substantial surgery-related morbidities, yet is typically not suitable for endovascular intervention. We describe a combined technique of supra-aortic trunk debranching through an anterior thoracotomy followed by endovascular repair of a large proximal arch aneurysm in an 82 year-old man 8 years after an ascending aortic aneurysm repair.

    View details for DOI 10.1016/j.jvs.2005.12.066

    View details for Web of Science ID 000237261400032

    View details for PubMedID 16678702

  • Carotid artery aneurysm: Evolution of management over two decades JOURNAL OF VASCULAR SURGERY Zhou, W., Lin, P. H., Bush, R. L., Peden, E., Guerrero, M. A., Terramani, T., Lubbe, D. F., Nguyen, L., Lumsden, A. B. 2006; 43 (3): 493-496

    Abstract

    Extracranial carotid artery aneurysm (CCA), although uncommon, represents a challenge to treatment strategy. The purpose of this study was to analyze the treatment evolution and clinical outcome of all patients with CCA over a two decade period.Clinical data of all patients diagnosed with CCA who underwent interventions from 1984 to 2004 were reviewed. Patients were divided into two groups. Group I (1985-1994) and group II (1995-2004) were compared with regards to clinical presentation, treatment modality, and clinical outcome.A total of 42 cases of CCA were found during the study period (group I, n=22; group II, n=20). Pulsatile neck mass was the most common presenting symptom (n=39, 93%), followed by neurological symptoms (n=6, 14%). Twenty two (52%) were atherosclerotic aneurysms, fifteen (36%) false aneurysms, and five (12%) posttraumatic aneurysms. Both groups shared similar comorbidities and demographic profiles. All patients in group I underwent operative interventions, which included 12 resection with interposition bypass grafting (55%), six resection with patch angioplasty (27%), and four carotid ligation (18%). In group II, five patients underwent resection with interposition placement (25%) and one carotid ligation (5%). The remaining 14 patients underwent endovascular interventions (70%) which included seven stent-graft exclusions, six carotid stenting with coil exclusions, and one endovascular occlusion. Hospital length of stay was significantly shorter in group II than group I (3.5 vs. 9.4 days, p<0.01). The incidence of cranial nerve injury in group I and II were 14% vs. 5% (p<0.04), respectively. The 30-day mortality/major stroke rates in group I and II were 14% vs. 5% (p< 0.04), respectively. During the follow-up period (0.8 months-20 years; mean, 4.6 years), 16 patients died, largely due to cardiac etiologies (n=11, 69%).Treatment modality of CCA has largely evolved from operative to endovascular intervention at our institution. Treatment benefits of endovascular modality include shorter convalescent and less procedural-related complications. This evolution reflects the improvement of endovascular devices and increased utility of endovascular applications.

    View details for DOI 10.1016/j.jvs.2005.11.023

    View details for Web of Science ID 000235848800012

    View details for PubMedID 16520161

  • Management of in-sent restenosis after carotid artery stenting in high-risk patients JOURNAL OF VASCULAR SURGERY Zhou, W., Lin, P. H., Bush, R. L., Peden, E. K., Guerrero, M. A., Kougias, P., Lumsden, A. B. 2006; 43 (2): 305-312

    Abstract

    Carotid artery stenting (CAS) has emerged as an acceptable treatment alternative in patients with carotid bifurcation disease. Although early results of CAS have been promising, long-term clinical outcomes remain less certain. We report herein the frequency, management, and clinical outcome of in-stent restenosis (ISR) after CAS at a single academic institution.Clinical records of 208 CAS procedures in 188 patients with carotid stenosis of 80% or greater, including 48 (26.5%) asymptomatic patients, during a 42-month period were analyzed. Follow-up serial carotid duplex ultrasound scans were performed. Selective angiography and repeat intervention were performed when duplex ultrasound scans showed 80% or greater ISR. Treatment outcomes of ISR interventions were analyzed.Over a median 17-month follow-up, 33 (15.9%) ISRs of 60% or greater were found, according to the Doppler criteria. Among them, seven patients (3.4%) with a mean age of 68 years (range, 65-87 years) developed high-grade ISR (> or =80%), and they all underwent further endovascular interventions. Six patients with high-grade ISR were asymptomatic, whereas one remaining patient presented with a transient ischemic attack. Five of seven ISRs occurred within 12 months of CAS, and two occurred at 18 months' follow-up. Treatment indications for initial CAS in these seven patients included recurrent stenosis after CEA (n = 4), radiation-induced stenosis (n = 1), and high-cardiac-risk criteria (n = 2). Treatment modalities for ISR included balloon angioplasty alone (n = 1), cutting balloon angioplasty alone (n = 4), cutting balloon angioplasty with stent placement (n = 1), and balloon angioplasty with stent placement (n = 1). Technical success was achieved in all patients, and no periprocedural complications occurred. Two patients with post-CEA restenosis developed restenosis after ISR interventions, both of whom were successfully treated with cutting balloon angioplasty at 6 and 8 months. The remaining five patients showed an absence of recurrent stenosis or symptoms during a mean follow-up of 12 months (range, 3-37 months). By using the Kaplan-Meier analysis, the freedom from 80% or greater ISR after CAS procedures at 12, 24, 36, and 42 months was 97%, 97%, 96%, and 94%, respectively.Our study showed that ISR after CAS remains uncommon. Successful treatment of ISR can be achieved by endovascular interventions, which incurred no instance of periprocedural complications in our series. Patients who developed ISR after CEA were likely to develop restenosis after IRS intervention. Diligent ultrasound follow-up scans are important after CAS, particularly in patients with post-CEA restenosis.

    View details for DOI 10.1016/j.jvs.2005.10.040

    View details for Web of Science ID 000235492300027

    View details for PubMedID 16476606

  • Aortic endograft infection due to Pasteurella multocida following a rabbit bite JOURNAL OF VASCULAR SURGERY Silberfein, E. J., Lin, P. H., Bush, R. L., Zhou, W., Lumsden, A. B. 2006; 43 (2): 393-395

    Abstract

    Abdominal aortic endograft infection is a serious complication after an endovascular abdominal aortic aneurysm repair. Pasteurella multocida, a gram-negative bacterium, is a commonly found organism in the mouth flora of many house pets. We report a case of an aortic endograft infection caused by P multocida after a rabbit bite. Successful treatment was performed by extra-anatomic revascularization followed by endograft removal.

    View details for DOI 10.1016/j.jvs.2005.10.067

    View details for Web of Science ID 000235492300042

    View details for PubMedID 16476621

  • Carotid artery stenting--current status and future directions. Minerva cardioangiologica Kougias, P., Lin, P. H., Bush, R. L., Peden, E. K., Zhou, W., Lumsden, A. B. 2006; 54 (1): 69-81

    Abstract

    Carotid endarterectomy has been the standard of therapy for carotid occlusive disease in stroke prevention. More recently, carotid angioplasty and stenting became an important alternative in the treatment of carotid occlusive disease. The widespread use of cerebral protection devices has substantially decreased the morbidity of the procedure. As the experience with carotid stenting increases, so does the enthusiasm for the potential of this minimally invasive carotid intervention to become the main treatment option for the high risk patients, as well as for the average asymptomatic patient. Although current available data indicate that the results regarding success and complication rates are similar between carotid stenting and endarterectomy, several prospective clinical trials are currently in progress to evaluate the efficacy of carotid artery stenting in different patient populations and definitively establish its role in the treatment of carotid disease. This paper reviews the current status of carotid stenting, including results from clinical trials, technical aspects and controversial issues and strategies to provide cerebral protection from embolization.

    View details for PubMedID 16467743

  • Endovascular treatment of traumatic thoracic aortic injury - should this be the new standard of treatment? JOURNAL OF VASCULAR SURGERY Lin, P. H., Bush, R. L., Zhou, W., Peden, E. K., Lumsden, A. B. 2006; 43: 22A-29A

    View details for DOI 10.1016/j.jvs.2005.10.068

    View details for Web of Science ID 000235690800006

    View details for PubMedID 16473166

  • In situ reconstruction with cryopreserved arterial allografts for management of mycotic aneurysms or aortic prosthetic graft infections: a multi-institutional experience TEXAS HEART INSTITUTE JOURNAL Zhou, W., Lin, P. H., Bush, R. L., Terramani, T. T., Matsuura, J. H., Cox, M., Peden, E., Guerrero, M., Silberfein, E. J., Dardik, A., Rosenthal, D., Lumsden, A. B. 2006; 33 (1): 14-18

    Abstract

    We designed this study to evaluate a multi-institutional experience regarding the efficacy of cryopreserved aortic allografts in the treatment of infected aortic prosthetic grafts or mycotic aneurysms. We reviewed clinical data of all patients from 4 institutions who underwent in situ aortic reconstruction with cryopreserved allografts for either infected aortic prosthetic graft or mycotic aneurysms from during a 6-year period. Relevant clinical variables and treatment outcomes were analyzed. A total of 42 patients (37 men; overall mean age 63 +/- 13 years, range 41-74 years) were identified during this study period. Treatment indications included 34 primary aortic graft infections (81%), 6 mycotic aneurysms (22%), and 2 aortoenteric erosions (5%). Transabdominal and thoracoabdominal approaches were used in 38 (90%) and 4 patients (10%), respectively. Staphylococcus aureus was the most commonly identified organism (n=27, 64%). Although there was no intraoperative death, the 30-day operative mortality was 17% (n=7). There were 21 (50%) nonfatal complications, including local wound infection (n=8), lower-extremity deep venous thrombosis (n=5), amputation (n=6), and renal failure requiring hemodialysis (n=2). The average length of hospital stay was 16.4 +/- 7 days. During a mean follow-up period of 12.5 months, reoperation for allograft revision was necessary in 1 patient due to graft thrombosis (6%). The overall treatment mortality rate was 21% (n=9). In situ aortic reconstruction with cryopreserved allografts is an acceptable treatment method in patients with infected aortic prosthetic graft or mycotic aneurysms. Our study showed that mid-term graft-related complications such as reinfection or aneurysmal degeneration were uncommon.

    View details for Web of Science ID 000236080500004

    View details for PubMedID 16572862

  • Repair of anastomotic abdominal aortic pseudoaneurysm utilizing sequential AneuRx aortic cuffs in an overlapping configuration ANNALS OF VASCULAR SURGERY Zhou, W., Bush, R. L., Bhama, J. K., Lin, P. H., Safaya, R., Lumsden, A. B. 2006; 20 (1): 17-22

    Abstract

    Anastomotic aortic pseudoaneurysm is a known late complication following aortic repair and presents a considerable surgical challenge. We herein evaluate the endovascular alternative of using sequential AneuRx aortic cuffs to bridge the degenerative anastomotic pseudoaneurysms as a definitive treatment. Over a 3-year period, six patients with a mean age of 68.7 years (range 58-75) were identified who had proximal anastomotic aortic pseudoaneurysms secondary to previously implanted bifurcated aortic grafts (mean 15, range 12-20 years) following open surgical correction of aortoiliac occlusive disease. Five patients (83%) presented with concomitant palpable femoral anastomotic pseudoaneurysms and one patient (16%) had a pulsatile abdominal mass. All patients had computed tomographic (CT) scans confirming proximal anastomotic pseudoaneuryms without evidence of infection. The mean diameter of the pseudoaneurysms was 5.3 cm (range 4.0-7.0). Five patients were treated with endovascular methods, while one patient was not suitable for endovascular repair due to the diameter of the native aorta as seen on imaging study at the time of the procedure. AneuRx aortic extender cuffs (3.75 cm length) were deployed sequentially in five patients via a femoral approach. Devices were overlapped approximately 1.5 cm in order to achieve total exclusion of the pseudoaneurysms, and all concomitant femoral aneurysms were repaired surgically at the same time. Successful exclusion of the anastomotic pseudoaneurysm was achieved in four patients (80%) using a combination of two or three overlapping aortic cuffs. One patient had a small residual endoleak that had sealed by 1 month, evidenced by follow-up CT. The renal arteries were preserved in all patients. The average estimated blood loss and operative time were 355 +/- 25 cc and 84 +/- 21 min, respectively. The average length of hospital stay was 2.1 days, and there was no mortality or major morbidity. All patients underwent CT scanning surveillance at 6 and 12 months and yearly afterward. There was no evidence of late endoleak, aneurysmal expansion, or device migration during the mean follow-up of 10 months, ranging 6-27 months. Our study demonstrated that utilizing sequential AneuRx aortic cuffs applied in an overlapping configuration is an effective strategy for degenerative aortic anastomotic pseudoaneurysm from previously placed aortic grafts. Additionally, our study suggests this unique endovascular technique is an ideal alternative for creating a customized tube graft in challenging cases, particularly in high-risk patients.

    View details for DOI 10.1007/s10016-005-9282-2

    View details for Web of Science ID 000234299700004

    View details for PubMedID 16378150

  • Carotid artery stenting with neuroprotection: assessing the learning curve and treatment outcome AMERICAN JOURNAL OF SURGERY Lin, P. H., Bush, R. L., Peden, E. K., Zhou, W., Guerrero, M., Henao, E. A., Kougias, P., Mohiuddin, I., Lumsden, A. B. 2005; 190 (6): 850-857

    Abstract

    Carotid artery stenting (CAS) has emerged as an acceptable treatment alternative in high-risk patients with carotid stenosis. The purpose of this study was to assess the effect of the learning curve on treatment complications and the clinical outcomes of CAS.Clinical variables and treatment outcomes of 200 consecutive CAS procedures in 182 patients (mean age 72 years) with carotid stenosis > or = 70% during a 40-month period were analyzed. Four sequential groups (groups I, II, III, and IV) of 50 consecutive interventions were compared with regard to technical success, periprocedural complications, and treatment outcomes.Treatment indications and relevant risk factors were similar among the 4 groups. The overall technical success and combined 30-day stroke and death rates were 98% and 2.5%, respectively. An increase in the technical success rate was noted in the latter 3 groups compared with group I (P < .05). Total procedural time and contrast volume were significantly higher in group I compared with the latter 3 groups (P < .05). The intraoperative anticoagulation regimen was changed from intravenous heparin combination to bivalirudin after the first 54 patients, which resulted in decreased bleeding complications in groups III and IV (P = 0.03) compared with the first group. The 30-day stroke and death rate in groups I and II were 8% and 2%, respectively, and was decreased significantly in groups III and IV (0% and 0%, respectively, P < .05). A Cox regression model identified procedural volume (P = .03) as a predictor of decreased complication rate.CAS with neuroprotection can provide excellent treatment outcomes. Our experience demonstrates a procedure-associated learning curve as evidenced by decreased procedure-related complications, fluoroscopic time, and contrast volume occurring with increased physician experience. Procedural success was also enhanced partly by endovascular device refinement and an improved anticoagulation regimen. Successful CAS outcomes can be achieved once physicians overcome the initial procedure-related learning curve.

    View details for DOI 10.1016/j.amsjurg.2005.08.008

    View details for Web of Science ID 000233759800006

    View details for PubMedID 16307933

  • Successful surgical management of pelvic congestion and lower extremity swelling owing to absence of infrarenal inferior vena cava VASCULAR Zhou, W., Rosenberg, W., Lumsden, A., Li, J. 2005; 13 (6): 358-361

    Abstract

    Absence of isolated infrarenal inferior vena cava (IVC) is a rare condition documented in only a few published cases and typically treated with anticoagulation. We herein describe successful surgical management of the isolated infrarenal IVC absence in a healthy 35-year-old woman who presented with disabling pelvic congestion. An ascending venogram showed the absence of infrarenal IVC with a large left ovarian vein draining pelvic collateral vessels to the normal left renal vein and suprarenal IVC. The patient was successfully treated with a common femoral vein to the suprarenal IVC bypass using a bifurcated polytetrafluoroethylene graft, with rapid symptom resolution, and remained symptom free 6 months later. This is the first reported case describing a surgical strategy for isolated infrarenal IVC absence in a symptomatic patient.

    View details for Web of Science ID 000235071900007

    View details for PubMedID 16390655

  • A comparison of carotid artery stenting with neuroprotection versus carotid endarterectomy under local anesthesia AMERICAN JOURNAL OF SURGERY Bush, R. L., Kougias, P., Guerrero, M. A., Lubbe, D. F., Zhou, W., Lumsden, A. B., Lin, P. H. 2005; 190 (5): 696-700

    Abstract

    Carotid endarterectomy (CEA) and carotid artery stenting (CAS) reduce the risk of stroke in patients with high-grade carotid artery stenosis. Despite the known impact of type of anesthesia on outcome after CEA, none of the current studies comparing CEA with CAS addresses the effect of anesthetic choice on perioperative events. In this study, we compare our results of distally protected CAS versus CEA under local anesthesia.Clinical data of 345 patients who underwent 372 procedures for carotid artery occlusive disease over a 36-month were retrospectively collected for this analysis. Distal embolic protection was used in CAS procedures. All procedures, both CEA (n = 221, 59%) and CAS (N = 152, 41%), were performed under local anesthesia. The primary outcome measure was aggregate 30-day major ipsilateral stroke and/or death. Follow-up serial Duplex ultrasound examinations were performed.Both patient cohorts were similar in terms of demographic and risk factors, with the exception of a higher incidence of coronary artery disease in the CAS group (59% versus 30%, P <.05). The 30-day stroke and death rates were 3.2% (CAS) and 3.7% (CEA) (P = not significant). Cranial nerve injury only occurred in the CEA patients (2.3%). Perioperative hemodynamic instability was more common among patients in the CAS group (11.9% versus 4.1%, P <.05).Percutaneous carotid stenting with neuroprotection provides comparable clinical success to CEA performed under local anesthetic. Further studies are warranted to validate the long-term efficacy of CAS and to elucidate patient selection criteria for endovascular carotid revascularization.

    View details for DOI 10.1016/j.amjsurg.2005.07.005

    View details for Web of Science ID 000232935200007

    View details for PubMedID 16226942

  • The case for thrombolysis for iliofemoral venous thrombosis. Seminars in vascular surgery Peden, E., Zhou, W., Bush, R. L., Lumsden, A. B., Lin, P. H. 2005; 18 (3): 139-147

    Abstract

    Deep venous thrombosis and its consequences remain a significant clinical challenge despite advances in the current healthcare system. The use of thrombolytic therapy has played an important role in the management of both arterial and venous thrombotic conditions. In this article, relevant clinical evidence and rationale in support of thrombolytic therapy in ileofemoral deep venous thrombosis are discussed.

    View details for PubMedID 16168889

  • What is the learning curve for carotid artery stenting with neuroprotection? Analysis of 200 consecutive cases at an academic institution. Perspectives in vascular surgery and endovascular therapy Lin, P. H., Bush, R. L., Peden, E., Zhou, W., Kougias, P., Henao, E., Mohiuddin, I., Lumsden, A. B. 2005; 17 (2): 113-123

    Abstract

    Carotid artery stenting (CAS) has emerged as an acceptable treatment alternative in high-risk patients with carotid stenosis. This study assessed the effect of the learning curve on treatment complications and clinical outcome of CAS. Clinical variables and treatment outcomes of 200 consecutive CAS procedures in 182 patients (mean age, 72 years) with carotid stenosis of 70% or greater during a 40-month period were analyzed. Technical success, periprocedural complications, and treatment outcomes were compared in four sequential groups (group I, II, III, and IV) of 50 consecutive interventions. Treatment indications and relevant risk factors were similar among the four groups. The overall technical success was 98%, and the combined 30-day stroke and death rates was 2.5%. An increase in the technical success rate was noted in the latter three groups compared with group I (P < .05). Total procedural time and contrast volume were significantly higher in group I compared with the latter three groups (P < .05). The intraoperative anticoagulation regimen was changed from an intravenous heparin combination to bivalirudin after the first 54 cases, resulting in reduced bleeding complications in groups III and IV (P = .03) compared with group I. The 30-day stroke and death rate in groups I and II was 8% and 2%, which was reduced significantly to 0% in groups III and IV (P < .05). A Cox regression model identified procedural volume (P = .03) as a predictor of a reduced complication rate. Carotid artery stenting with neuroprotection can provide excellent treatment outcome. Our experience demonstrates a procedural-associated learning curve, as evidenced by the reduced procedural-related complications, fluoroscopic time, and contrast volume that occurred with an increase in physician experience. The procedural success is also enhanced partly by endovascular device refinement and improved anticoagulation regimen. Successful outcome of CAS can be achieved once physicians overcome the initial procedural-related learning curve.

    View details for PubMedID 16110374

  • Fibromuscular dysplasia of the carotid artery JOURNAL OF THE AMERICAN COLLEGE OF SURGEONS Zhou, W., Bush, R. L., Lin, P. L., Lumsden, A. B. 2005; 200 (5): 807-807
  • Ginsenoside Rb1 blocks homocysteine-induced endothelial dysfunction in porcine coronary arteries JOURNAL OF VASCULAR SURGERY Zhou, W., Chai, H., Lin, P. H., Lumsden, A. B., Yao, Q. Z., Chen, C. Y. 2005; 41 (5): 861-868

    Abstract

    Homocysteine (Hcy) is an independent risk factor for atherosclerosis. This study investigates the effects of ginsenoside Rb1, a major constituent of ginseng, on Hcy-induced endothelial dysfunction and molecular changes in porcine coronary arteries.The coronary arteries were harvested from pig hearts and cut into 5-mm ring segments, which were then divided into six groups, including control, Hcy alone (50 microM), low-dose (1 microM) or high-dose (10 microM) Rb1 alone, and Hcy plus low-dose or high-dose Rb1. After 24-hour incubation, the rings were analyzed for vasomotor function in response to thromboxane A2 analog U46619, bradykinin, and sodium nitroprusside (SNP), respectively. In addition, superoxide anion was assessed by lucigenin-enhanced chemiluminescence analysis. Endothelial nitric oxide synthase (eNOS) was studied using real-time polymerase chain reaction and Western blot.Endothelium-dependent relaxation (bradykinin) was significantly reduced in rings treated with Hcy alone as compared with the control (49.80% vs 71.77%, n = 8, P < .05), whereas neither high-dose nor low-dose Rb1 alone affected the endothelium-dependent relaxation. The low-dose Rb1-Hcy combined group had a partially improved endothelium-dependent relaxation (54.44%), whereas the high-dose Rb1-Hcy combined group showed a complete recovery of endothelium-dependent relaxation (72.89%). There was no substantial difference in maximal contraction induced by U46619 or endothelium-independent relaxation by SNP among all groups (P > .05). Furthermore, superoxide anion was markedly increased by 137% in the Hcy-treated group as compared with the control, but there were no statistically significant changes from the control in all other groups (P > .05). Lastly, eNOS mRNA and protein levels were substantially reduced in the Hcy-treated group, but not in the Rb1-Hcy combined groups.This is the first study to show that ginsenoside Rb1 can effectively block Hcy-induced endothelial dysfunction and superoxide anion production as well as eNOS downregulation in porcine coronary arteries. This study suggests that ginseng and its active constituents may have potential clinical applications in controlling Hcy-associated vascular injuries.Homocysteine (Hcy) is an independent risk factor for atherosclerosis and other vascular lesions. It causes endothelial dysfunction and oxidative stress. Ginseng compounds have effects of vasorelaxation and antioxidation. The purpose of this study was to determine the effect of ginsenoside Rb1, a major constituent of ginseng, on Hcy-induced endothelial dysfunction and molecular changes in porcine coronary arteries. Our results showed that ginsenoside Rb1 can effectively block Hcy-induced dysfunction of endothelium-dependent vasorelaxation as well as superoxide anion production and eNOS downregulation. This study suggests that ginseng compounds may have potential clinical applications in controlling Hcy-associated vascular diseases and other vascular lesions.

    View details for DOI 10.1016/j.jvs.2005.01.054

    View details for Web of Science ID 000229092300022

    View details for PubMedID 15886672

  • The impact of anesthetic modality on the outcome of carotid endarterectomy AMERICAN JOURNAL OF SURGERY Watts, K., Lin, P. H., Bush, R. L., Awad, S., McCoy, S. A., Felkai, D., Zhou, W., Nguyen, L., Guerrero, M. A., Shenaq, S. A., Lumsden, A. B. 2004; 188 (6): 741-746

    Abstract

    Carotid endarterectomy (CEA) reduces the risk of stroke in patients with high-grade carotid artery stenosis. This study evaluates the clinical outcome of CEA performed under local anesthesia (LA) versus general anesthesia (GA).Clinical variables and treatment outcomes were analyzed in 548 CEAs performed under either LA or GA during a 30-month period. Factors associated with morbidity were also analyzed.A total of 263 CEAs under LA and 285 CEA under GA were analyzed. The LA group was associated with a lower incidence of shunt placement, operative time, and perioperative hemodynamic instability compared to the GA group. No differences in neurologic complications or mortality were found between the 2 groups. Hyperlipidemia was a risk factor for postoperative morbidity in both the LA and GA groups, while age greater than 75 years was associated with increased overall morbidity in the GA group but not the LA group.This study demonstrates that increased age is associated with increased morbidity in CEA under GA, while hyperlipidemia is associated with increased morbidity in CEA regardless of the anesthetic choice.

    View details for DOI 10.1016/j.amjsurg.2004.08.048

    View details for Web of Science ID 000226183600036

    View details for PubMedID 15619493

  • Abdominal aortic surgery in patients with human immunodeficiency virus infection AMERICAN JOURNAL OF SURGERY Lin, P. H., Bush, R. L., Yao, Q. Z., Lam, R., Paladugu, R., Zhou, W., Chen, C. Y., Lumsden, A. B. 2004; 188 (6): 690-696

    Abstract

    Human immunodeficiency virus (HIV) infection is known to cause acquired immune deficiency syndrome, which has been associated with a wide array of cardiovascular pathologies. This report examined the clinical outcome of patients infected with HIV who underwent abdominal aortic reconstruction for aneurysm or occlusive disease.Hospital and clinic records of all patients with HIV infection who underwent an abdominal aortic operation were reviewed during an 11-year period. Relevant risk factors and clinical variables were assessed for surgical outcome.Forty-eight HIV patients (mean age 54 +/- 13 years) were identified who underwent abdominal aortic bypass grafting during the study period. Indications for aortic operation included aneurysm (n = 20) and aortoiliac occlusive disease (n = 28). All patients underwent successful aortic reconstructions without intraoperative mortality. Postoperative complications and in-hospital mortality occurred in 16 patients (33%) and 7 patients (15%), respectively. The mean follow-up period was 41 months. Life-table survival rates in aneurysm and occlusive patients at 60 months were 43.2% +/- 5.3% and 46.3% +/- 7.4% (not significant), respectively. Multivariate analysis showed that low CD4 lymphocyte counts (< 200/microL, P <0.05) and hypoalbuminemia (<3.5 g/dL, P <0.05) were risk factors for postoperative complications.Perioperative morbidity and mortality rates are high in HIV patients undergoing an abdominal aortic operation. Low CD4 lymphocyte counts and hypoalbuminemia are associated with poor clinical outcomes in HIV patients undergoing abdominal aortic reconstruction.

    View details for DOI 10.1016/j.amjsurg.2004.08.054

    View details for Web of Science ID 000226183600020

    View details for PubMedID 15619485

  • Carotid artery stenting with routine cerebral protection in high-risk patients AMERICAN JOURNAL OF SURGERY Lin, P. E., Bush, R. L., Lubbe, D. F., Cox, M. M., Zhou, W., McCoy, S. A., Felkai, D., Paladugu, R., Lumsden, A. B. 2004; 188 (6): 644-650

    Abstract

    Carotid artery stenting has emerged as an alternative treatment modality in carotid occlusive disease. This study examined our experience of carotid stenting with routine cerebral embolization protection in high-risk patients.Clinical variables and treatment outcome of high-risk patients who underwent carotid stenting with neuroprotection were analyzed during a 26-month period.Sixty-eight high-risk patients with 72 carotid artery stenoses were treated. Procedural success was achieved in 70 cases (97%), and symptomatic lesions existed in 17 (24%) patients. Monorail Wallstents stents were used in all cases. Neuroprotective devices used were PercuSurge (28%) and Filterwire (72%). There was no periprocedural mortality or neuroprotective device-related complications. The 30-day stroke and death rate was 2.7%, and the overall complication rate was 6.9%. All stented vessels remained patent during the follow-up period (mean 15.3 +/- 4.2, range 1 to 23 months). Two asymptomatic in-stent restenosis (3%) occurred at 6 and 8 months, which were both successfully treated with balloon angioplasty.Our study showed that percutaneous carotid stenting with routine use of a cerebral protection device is a feasible and effective treatment in high-risk patients with carotid occlusive disease.

    View details for DOI 10.1016/j.amjsurg.2004.08.035

    View details for Web of Science ID 000226183600006

    View details for PubMedID 15619478

  • Treatment options of iatrogenic pelvic vein injuries: conventional operative versus endovascular approach--case reports. Vascular and endovascular surgery Zhou, W., Bush, R. L., Terramani, T. T., Lin, P. H., Lumsden, A. B. 2004; 38 (6): 569-573

    Abstract

    Iatrogenic injury to the iliac vein or inferior vena cava (IVC), which may occur during abdominal operations or posterior orthopedic procedures, can have devastating consequences. Operative management is challenging and may be associated with significant morbidity. The authors report herein 3 cases of iatrogenic pelvic vein injuries that were managed with different treatment approaches. Both traditional open surgical therapy and endovascular techniques are described.

    View details for PubMedID 15592639

  • Pharmacomechanical thrombectomy for treatment of symptomatic lower extremity deep venous thrombosis: Safety and feasibility study JOURNAL OF VASCULAR SURGERY Bush, R. L., Lin, P. H., Bates, J. T., Mureebe, L., Zhou, W., Lumsden, A. B. 2004; 40 (5): 965-970

    Abstract

    The current standard of care for deep venous thromboembolism (DVT) is anticoagulation; however, this treatment method does not rapidly relieve clot burden or clinical symptoms. We describe a rapid and effective method of thrombus removal, with simultaneous percutaneous mechanical thrombectomy (PMT) and thrombolysis.Over 26 months 20 patients (22 men, 2 women; mean age, 52 +/- 6 years [range, 38-79 years]) with extensive lower extremity DVT were treated with PMT with the AngioJet thrombectomy device in combination with lytic agent (urokinase, tissue plasminogen activator, or reteplase) added to the infusion. Three patients underwent treatment twice, because of recurrent DVT. The primary end point was angiographic evidence of restoration of venous patency at completion of the procedure. Complications, recurrent ipsilateral DVT, and improvement in clinical symptoms were evaluated.Complete thrombus removal was obtained in 15 procedures (65%), and partial resolution in the remaining 8 procedures (35%). Inciting occlusive lesions responsible for acute DVT were revealed in 14 patients (61%), and angioplasty with or without stenting was performed when necessary. In the 8 procedures with partial resolution additional catheter-directed thrombolysis was carried out on average for 5.7 hours, with further thrombus reduction. Overall, immediate (<24 hours) improvement in clinical symptoms was noted in 17 patients (74%). There were no complications related to either PMT or the short duration of lytic agent infusion. At average follow-up of 10.2 +/- 0.3 months (range, 3-26 months), 3 patients had recurrent ipsilateral DVT, and underwent repeat treatment.Addition of lytic agent to PMT facilitates thrombus extraction, decreases overall interventional treatment time, and improves patient outcomes. In addition, definitive management of underlying anatomic lesions can be performed in the same setting. Further outcome measures are necessary to study the long-term efficacy of this treatment method on preservation of valve function, reduction of chronic venous insufficiency, and improved quality of life.

    View details for DOI 10.1016/j.jvs.2004.08.025

    View details for Web of Science ID 000227389100027

    View details for PubMedID 15557912

  • Acute arterial thrombosis associated with cocaine abuse JOURNAL OF VASCULAR SURGERY Zhou, W., Lin, P. H., Bush, R. L., Nguyen, L., Lumsden, A. B. 2004; 40 (2): 291-295

    Abstract

    Cocaine-induced arterial thrombosis is uncommon, and most reported cases involved small-diameter vessels such as the cerebral and coronary arteries. This study was undertaken to review our experience with peripheral arterial thrombosis presumed caused by cocaine abuse.Hospital records were reviewed for all patients admitted over 10 years with acute arterial occlusion involving the peripheral arterial system. Patients with confirmation of cocaine use or of its derivative, crack cocaine, within 24 hours of hospital admission formed the basis of this study. Symptoms at presentation, management, and outcome in these patients were reviewed.Three hundred eighty-two patients with acute peripheral arterial occlusion were identified during the study period. The presumptive diagnosis of cocaine-induced arterial occlusion was made in 5 patients (4 men, mean age 38 years). Cocaine use was achieved via intranasal inhalation in 2 patients (40%), whereas the 3 remaining patients smoked crack cocaine (60%). The mean time between cocaine use and onset of arterial thrombosis was 9.2 hours (range, 2-20 hours). Symptoms at presentation included acute limb ischemia without pedal Doppler signals (3 patients, 60%) and abdominal pain without femoral pulses (2 patients, 40%). Arterial occlusion was confirmed on angiograms in all patients, which revealed aortic thrombosis in 1 patient (20%), iliac thrombosis in 2 patients (40%), superficial femoral artery thrombosis in 1 patient (20%), and popliteal artery occlusion in 1 patient (20%). Surgical thrombectomy was successfully performed in 4 patients (80%), and 1 patient (20%) underwent successful thrombolytic therapy for femoropopliteal artery occlusion. There was no perioperative mortality. All 5 patients who were discharged were available for follow-up (mean, 36 months; range, 6-75 months). There was 1 late death from myocardial infarction. In 1 patient recurrent lower extremity arterial thrombosis developed after 28 months, which was successfully treated with thrombolytic therapy.Our study underscores cocaine abuse as a potential cause of acute arterial thrombosis. Cocaine-induced arterial thrombosis should be suspected in patients with recent history of cocaine abuse with acute limb ischemia without an identifiable source or overt cardiovascular risk factors. Prompt angiography with operative or endovascular intervention should be performed to avert arterial ischemic sequelae.

    View details for Web of Science ID 000227388100017

    View details for PubMedID 15297823

  • Molecular mechanisms and clinical applications of ginseng root for cardiovascular disease MEDICAL SCIENCE MONITOR Zhou, W., Chai, H., Lin, P. H., Lumsden, A. B., Yao, Q. Z., Chen, C. Y. 2004; 10 (8): RA187-RA192

    Abstract

    Ginseng root is used extensively in traditional Chinese medicine for its alleged tonic effect and possible curative and restorative properties. There are increasing evidences in the literature on the potential role of ginseng in treating cardiovascular diseases. We herein examine the history of ginseng usage and review the current literature on a myriad pharmacological function of ginseng on the cardiovascular system. From the published studies involving cell cultures and animal models, ginseng is shown to have potential benefits on the cardiovascular system through diverse mechanisms, including antioxidant, modifying vasomotor function, reducing platelet adhesion, influencing ion channels, altering autonomic neurotransmitters release, improving lipid profiles, and involving in glucose metabolism and glycemic control. In addition, the relevant clinical trials regarding the effects of ginseng on the cardiovascular disease are summarized, particularly in managing hypertension and improving cardiovascular function. Finally, the controversies in the literature and the possible adverse interactions between ginseng and other drugs are discussed. This review underscores the potential benefit effects of ginseng on cardiovascular diseases, highlights the gaps in our current research, and emphasizes the necessity for more rigorous systemic investigation.

    View details for Web of Science ID 000224833700024

    View details for PubMedID 15278009

  • Radiation-associated venous stenosis: Endovascular treatment options JOURNAL OF VASCULAR SURGERY Zhou, W., Bush, R. L., Lin, P. H., Lumsden, A. B. 2004; 40 (1): 179-182

    Abstract

    We report a case of radiation-induced venous stenosis after pelvic irradiation to treat Paget's disease of the scrotum. During therapeutic anticoagulation, significant left lower extremity swelling developed due to an iliofemoral deep venous thrombosis (DVT). After percutaneous thrombectomy and thrombolysis, a high-grade stenosis was uncovered in the left external iliac vein, which was treated with an endoluminal stent. However, ipsilateral DVT recurred 2 months later despite continued anticoagulation therapy. Repeat treatment was successful. Pelvic radiation is a potential cause of iliac vein stenosis. Pharmacomechanical thrombectomy may have a useful role in management of complex iliofemoral DVT.

    View details for DOI 10.1016/j.jvs.2004.03.039

    View details for Web of Science ID 000222522300030

    View details for PubMedID 15218482

  • Clinical use and molecular mechanisms of action of extract of Ginkgo biloba leaves in cardiovascular diseases CARDIOVASCULAR DRUG REVIEWS Zhou, W., Chai, H., Lin, P. H., Lumsden, A. B., Yao, Q. Z., Chen, C. Y. 2004; 22 (4): 309-319

    Abstract

    Ginkgo biloba is one of the oldest living tree species that has been referred to as a living fossil. Extract from Ginkgo biloba leaves (GBE) is among the most commonly used herbal drugs and is popularized for its alleged tonic effect and possible curative and restorative properties. There is an increasing evidence of the potential role of GBE in treating cardiovascular diseases. We examined the history of GBE usage and reviewed the literature on its effects on the cardiovascular system. In the extensive studies involving cell cultures and animal models, GBE has been shown to exert its action through diverse mechanisms. GBE has been reported to have antioxidatant properties, to modify vasomotor function, to reduce adhesion of blood cells to endothelium, to inhibit activation of platelets and smooth muscle cells, to affect ion channels, and to alter signal transduction. In addition, relevant clinical trials with CBE are being carried out, particularly in the treatment of arterial and venous insufficiency and in the prevention of thrombosis. Finally, the controversial clinical findings and the possible adverse interactions between GBE and other drugs are discussed. This review underscores the potential benefits of Ginkgo biloba in cardiovascular diseases, highlights the gaps in our current research, and suggests the necessity for more rigorous systematic investigation of cardiovascular properties of CBE.

    View details for Web of Science ID 000226432200003

    View details for PubMedID 15592576

Conference Proceedings


  • Prospective Neurocognitive Evaluation of Patients Undergoing Carotid Interventions Hitchner, E., Gillis, K., Sun, L., Rosen, A., Zhou, W. MOSBY-ELSEVIER. 2012: 621-621
  • Hypogastric Artery Preservation During Aortoiliac Aneurysm Repair Casey, K., Al-Khatib, W. K., Zhou, W. ELSEVIER SCIENCE INC. 2011

    Abstract

    Hypogastric artery (HA) embolization with iliac limb extension is often performed for patients with concomitant aorta and common iliac artery aneurysms at the time of standard endovascular aneurysm repair. However, symptomatic pelvic ischemia following HA exclusion can be debilitating. In this study, we described two cases of HA preservation using commercially available stent grafts. The techniques that we described enable patients with concurrent aorta and iliac aneurysms to undergo endovascular aneurysm repair without increasing the risk of pelvic ischemia. Although the long-term durability of these trifurcated graft configurations remains to be determined, the short-term results are superb. Technical considerations of these two different approaches have also been compared.

    View details for DOI 10.1016/j.avsg.2010.06.008

    View details for Web of Science ID 000285480200022

    View details for PubMedID 20889293

  • Protein Kinase C-epsilon Mediates Resistin-Induced Human Coronary Artery Smooth Muscle Cell Proliferation Ding, R. Q., Chai, H., Mochly-Rosen, D., Zhou, W. LIPPINCOTT WILLIAMS & WILKINS. 2010: E265-E265
  • Interrater Reliability of Microemboli Volume Measurements Following Carotid Interventions Dinishak, D., Zhou, W., Ortega, M., Zareie, R., Lane, B., Rosen, A. LIPPINCOTT WILLIAMS & WILKINS. 2009: E100-E100

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