Bio

Clinical Focus


  • Vascular & Interventional Radiology
  • Acute PE
  • Complex IVC Filter Retrieval
  • Diagnostic Radiology
  • Acute and Chronic DVT
  • Peripheral Arterial Disease
  • Arterial & Venous Chronic Total Occlusions

Academic Appointments


Administrative Appointments


  • Director-Stanford IVC Filter Clinic, Division of Vascular & Interventional Radiology - Stanford University Medical Center (2010 - Present)
  • Director-Interventional Radiology Fellowship Program, Department of Radiology - Stanford University Medical Center (2008 - Present)

Honors & Awards


  • Vitals Compassionate Doctor Award, Vitals.com (2013)
  • Patients' Choice Award, PatientsChoice.org (2013)
  • Featured Manuscript, Journal of Vascular and Interventional Radiology (2013)
  • U.S. News Top Doctors, U.S. News & World Report (2013)
  • Castle Connolly Top Doctors, Castle Connolly Medical Ltd. (2013)
  • Compassionate Doctor Award, PatientsChoice.org (2012)
  • Top 10 Doctor Award, Vitals.com (2012)
  • Patients' Choice Award, PatientsChoice.org (2012)
  • Letter of Commendation-Interventional Radiology Fellowship Program, ACGME (2012)
  • Dr. Gary J. Becker Young Investigator Award, Society of Interventional Radiology Foundation (2011)
  • Featured Manuscript, Journal of Vascular and Interventional Radiology (2011)
  • Elected to Fellowship, Society of Interventional Radiology (2011)
  • Outstanding Faculty Award, Society of Interventional Radiology (2010)
  • Featured Manuscript-SIR National Press Release, Society of Interventional Radiology (2009)
  • SIR Leadership Academy, Society of Interventional Radiology (2009)
  • Featured Manuscript-ACR/Reuters National Press Release, American College of Radiology (2008)
  • Elected To Fellowship, American College of Chest Physicians (2008)
  • Top 5 Best Poster Award, American College of Chest Physicians (2007)
  • Distinguished Reviewer Award, Journal of Vascular and Interventional Radiology (2007)
  • Chief Resident in Radiology, University of Rochester Medical Center (2005)
  • Featured Manuscript-JVIR/SIR National Press Release, Society of Interventional Radiology (2003)
  • I. Meschan Radiology Merit Award, Wake Forest University School of Medicine (2000)

Professional Education


  • Fellowship:Stanford University Medical Center (2006) CA
  • Residency:University of Rochester (2005) NY
  • Internship:Virginia Mason Medical Center (2001) WA
  • Medical Education:Wake Forest University-School of Medicine (2000) NC
  • College, Duke University, BS in Biology with Honors, NC (1996)
  • Board Certification: Diagnostic Radiology, American Board of Radiology (2005)
  • Board Certification: Vascular and Interventional Radiology, American Board of Radiology (2007)

Community and International Work


  • SYNTHESIS COLLABORATIVE, International

    Topic

    Teleradiology Services

    Partnering Organization(s)

    Hope Foundation for Women and Children

    Populations Served

    Third World Countries

    Location

    International

    Ongoing Project

    Yes

    Opportunities for Student Involvement

    No

  • CANARY CHALLENGE

    Partnering Organization(s)

    CANARY FOUNDATION

    Populations Served

    Cancer Patients

    Location

    Bay Area

    Ongoing Project

    Yes

    Opportunities for Student Involvement

    No

  • BIKE 4 BREATH

    Partnering Organization(s)

    Breath California

    Populations Served

    asthma, emphysema, pulmonary hypertension, lung cancer, TB, and other forms of lung disease

    Location

    California

    Ongoing Project

    Yes

    Opportunities for Student Involvement

    Yes

Research & Scholarship

Current Research and Scholarly Interests


1) LASER-ASSISTED AND COMPLEX IVC FILTER RETRIEVAL
2) CATHETER-DIRECTED THERAPY FOR ACUTE PULMONARY EMBOLISM
3) INTERNATIONAL PE REGISTRY
4) IVC FILTER REGISTRY
5) ENDOVASCULAR TREATMENT OF CAVAL AND DEEP VENOUS THROMBOSIS

Clinical Trials


  • A Prospective, Single-arm, Multi-center Trial of EkoSonic® Endovascular System and Activase for Treatment of Acute Pulmonary Embolism (PE). Recruiting

    The purpose of this study is to determine if the EKOS EkoSonic® Endovascular Device when used in conjunction with recombinant t-PA as a treatment for acute pulmonary embolism (PE) will decrease the ratio of RV to LV diameter within 48 ± 6 hours in patients with massive or submassive PE.

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  • ExAblate (Magnetic Resonance-guided Focused Ultrasound Surgery) Treatment of Metastatic Bone Tumors for the Palliation of Pain Not Recruiting

    A Pivotal Study to Evaluate the Effectiveness and Safety of ExAblate Treatment of Metastatic Bone and Multiple Myeloma Tumors for the Palliation of Pain in Patients Who are not Candidates for Radiation Therapy

    Stanford is currently not accepting patients for this trial. For more information, please contact Kamil Unver, (650) 725 - 9810.

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  • Pulmonary Embolism Response to Fragmentation, Embolectomy, & Catheter Thrombolysis: PERFECT Recruiting

    A prospective observational study to evaluate the safety and effectiveness data of catheter-directed therapy (CDT) including percutaneous mechanical thrombectomy (PMT) for treatment of acute pulmonary embolism (PE)

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  • A Phase 2b Study of Modified Vaccinia Virus to Treat Patients Advanced Liver Cancer Who Failed Sorafenib Not Recruiting

    This study is to determine whether JX-594 (Pexa-Vec) plus best supportive care is more effective in improving survival than best supportive care in patients with advanced Hepatocellular Carcinoma (HCC) who have failed sorafenib.

    Stanford is currently not accepting patients for this trial. For more information, please contact Fizaa Ahmed, (650) 725 - 6409.

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  • Impact of C-arm CT in Patients With HCC Undergoing TACE: Optimal Imaging Guidance Not Recruiting

    Patients will be enrolled based on presence of HCC and eligibility for TACE. They will be randomized to one of two arms for imaging navigation to the optimal catheter location for chemotherapy injection to treat the first (possibly sole) tumor target. The two arms will be: TACE using F and DSA only, or TACE using F, DSA, and CACT. Navigation to subsequent treatment targets in all patients will be done with fluoroscopy, CACT, and DSA, as is standard of care at Stanford University Medical Center, and is not part of the study. Vascular complexity, which affects navigation difficulty and thus the need for imaging, will be assessed separately for use in data analysis by two radiologists on a four-point scale.

    Stanford is currently not accepting patients for this trial. For more information, please contact Kamil Unver, (650) 725 - 9810.

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  • The GORE Viabahn Endoprosthesis for the Treatment of Venous Occlusions and Stenoses Recruiting

    To study the safety and efficacy of drug coated stents for the treatment of venous occlusions and stenoses in the lower extremity. The use of the device for the treatment of peripheral arterial disease is approved by the FDA, however, the use of the device in venous occlusions and stenoses, although performed by some practitioners, has not yet been studied in detail.

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

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

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

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  • Impact of C-arm CT in Decreased Renal Function Undergoing TACE for Tx of Hepato-Cellular Carcinoma Not Recruiting

    Impact on contrast dose or total volume of contrast required to effectively treat the targeted tumor.

    Stanford is currently not accepting patients for this trial. For more information, please contact Kamil Unver, (650) 725 - 9810.

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  • HepaSphere/Quadrasphere Microspheres for Delivery of Doxorubicin for the Treatment of Hepatocellular Cancer Recruiting

    The purpose of this study is to evaluate overall survival in patients treated with HepaSphere/QuadraSphere compared to conventional transarterial chemoembolization with particle PVA.

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  • Acute Venous Thrombosis: Thrombus Removal With Adjunctive Catheter-Directed Thrombolysis Recruiting

    The purpose of this study is to determine if the use of adjunctive Pharmacomechanical Catheter Directed Thrombolysis, which includes the intrathrombus administration of rt-PA--Activase (Alteplase),can prevent the post-thrombotic syndrome(PTS)in patients with symptomatic proximal deep vein thrombosis(DVT)as compared with optimal standard DVT therapy alone.

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  • FILTER - Filter Initial & Long Term Evaluation After Placement and Retrieval (Including Laser-Assisted Retrieval) Registry Recruiting

    A data registry for all patients who undergo IVC (Inferior Vena Cava) filter placement or retrieval at Stanford. Potential enrollees will already be undergoing the procedure. If patients are willing, they will be prospectively enrolled prior to the procedure. As part of the study, chart and clinical data reviews will be used to track patient progress and response to the treatment.

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Teaching

2013-14 Courses


Publications

Journal Articles


  • Vena Tech LGM Filter Retrieval 16 Years after Implantation: Piecemeal Removal by Intentional Mechanical Fracture. Journal of vascular and interventional radiology Kuo, W. T., Deso, S. E., Robertson, S. W. 2013; 24 (11): 1731-1737

    Abstract

    A 48-year-old man presented with symptomatic inferior vena cava (IVC) occlusion from a chronically thrombosed and embedded Vena Tech LGM filter resulting in exercise intolerance from diminished cardiac preload and postthrombotic syndrome from chronic venous insufficiency. The patient was treated using a new PRIME technique-Piecemeal Removal by Intentional MEchanical fracture-to achieve successful filter retrieval 16 years after implantation. Removal of the obstructing filter permitted endovascular IVC recanalization with restoration of venous outflow and alleviation of venous obstructive symptoms. Cardiac preload was restored, allowing the patient to resume long-distance running, and he successfully completed a half-marathon 3 months after treatment.

    View details for DOI 10.1016/j.jvir.2013.07.028

    View details for PubMedID 24160825

  • Excimer laser-assisted removal of embedded inferior vena cava filters: a single-center prospective study. Circulation. Cardiovascular interventions Kuo, W. T., Odegaard, J. I., Rosenberg, J. K., Hofmann, L. V. 2013; 6 (5): 560-566

    Abstract

    Although chronically implanted inferior vena cava filters may result in filter-related morbidity, there is currently no routine option for removing such filters when they become firmly embedded along the vena cava endothelium.During a 3-year period, 100 consecutive patients were prospectively enrolled in a single-center study. There were 42 men and 58 women (mean age, 46 years; limits, 18-76 years). Retrieval indications included filter-related acute inferior vena cava thrombosis, chronic inferior vena cava occlusion, and pain from retroperitoneal or bowel penetration. Filter retrieval was also performed to prevent risks from prolonged implantation and to potentially eliminate the need for lifelong anticoagulation. After standard methods failed, photothermal tissue ablation was attempted with a laser sheath powered by a 308-nm xenon chloride excimer laser. Applied forces were recorded with a digital tension meter before and during laser activation. Laser-assisted retrieval was successful in 98.0% (95% confidence interval [CI], 93.0%-99.8%) with mean implantation of 855 days (limits, 37-6663 days; >18 years). The following filter types were encountered in this study: Günther-Tulip (n=34), Celect (n=12), Option (n=17), Optease (n=20, 1 failure), TrapEase (n=6, 1 failure), Simon-Nitinol (n=1), 12F Stainless Steel Greenfield (n=4), and Titanium Greenfield (n=6). The average force during failed standard retrievals was 7.2 versus 4.6 pounds during laser-assisted retrievals (P<0.0001). The major complication rate was 3.0% (95% CI, 0.6%-8.5%), the minor complication rate was 7.0% (95% CI, 0.3%-13.9%), and there were 4 adverse events (2 coagulopathic hemorrhages, 1 renal infarction, and 1 cholecystitis; 4.0%; 95% CI, 1.1%-9.9%) at mean follow-up of 500 days (limits, 84-1079 days). Scar tissue ablation was histologically confirmed in 96.0% (95% CI, 89.9%-98.9%). Successful retrieval allowed cessation of anticoagulation in 30 of 30 (100%) patients and alleviated morbidity in 23 of 24 patients (96%).Excimer laser-assisted removal is effective in removing embedded inferior vena cava filters refractory to standard retrieval and high force. This method can be safely used to prevent and alleviate filter-related morbidity.http://www.clinicaltrials.gov. Unique identifier: NCT01158482.

    View details for DOI 10.1161/CIRCINTERVENTIONS.113.000665

    View details for PubMedID 24065445

  • Complex retrieval of fractured, embedded, and penetrating inferior vena cava filters: a prospective study with histologic and electron microscopic analysis. Journal of vascular and interventional radiology Kuo, W. T., Robertson, S. W., Odegaard, J. I., Hofmann, L. V. 2013; 24 (5): 622-630 e1

    Abstract

    To evaluate clinical outcomes, characterize adherent tissue, and analyze inferior vena cava (IVC) filter fractures in patients undergoing complex retrieval for management of filter-related complications. To elucidate mechanisms of filter fracture by radiographic and electron microscopic (EM) evaluation.Over 2.5 years, 50 consecutive patients with fractured and/or penetrating filter components were prospectively enrolled into a single-center study. There were 19 men and 31 women (mean age, 42 y; range, 15-73 y). All patients underwent complex filter retrieval after failure of standard methods, and retrieval indications along with resultant clinical outcomes were evaluated. Specimens with adherent tissue underwent histologic analysis, and all fractured components were studied with EM.Retrieval was successful in all 50 cases (mean implantation, 815 d; range, 20-2,599 d) among the following filters: G2X (n = 23),G2 (n = 9), Eclipse (n = 3), Recovery (n = 4), ALN (n = 1), Celect (n = 7), OptEase (n = 2), and Simon Nitinol (n = 1). Mean indwell time in fractured filters (n = 31) was 1,082 days, versus 408 days in nonfractured filters (n = 19; P = .00169). Neointimal hyperplasia/fibrosis was seen in 46 of 48 specimens with adherent tissue (96%). Among 61 fractured components from conical filters, 35 had extravascular penetration whereas 26 remained intravascular (11 free-floating in IVC, 15 embolized centrally), and EM revealed fracture modes of high-cycle fatigue (n = 53), overload (n = 6), and indeterminate (n = 2). Following retrieval, previously prescribed lifelong anticoagulation was discontinued in 30 of 31 patients (97%). Filter-related symptoms from IVC occlusion, component embolization, and penetration-induced abdominal pain, duodenal injury, and/or small-bowel volvulus were alleviated in all 26 cases (100%). There were no long-term complications at a mean follow-up of 371 days (range, 67-878 d).The risk of filter fracture increases after 408 days (ie,>1 y) of implantation and is associated with symptomatic extravascular penetration and/or intravascular embolization. Complex methods can be used to safely remove these devices, alleviate filter-related morbidity, and allow cessation of anticoagulation.

    View details for DOI 10.1016/j.jvir.2013.01.008

    View details for PubMedID 23523157

  • Optimizing Catheter-directed Thrombolysis for Acute Deep Vein Thrombosis: Validating the Open Vein Hypothesis JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kuo, W. T. 2013; 24 (1): 24-26

    View details for DOI 10.1016/j.jvir.2012.10.023

    View details for Web of Science ID 000313598300004

    View details for PubMedID 23273694

  • Complex Retrieval of Embedded IVC Filters: Alternative Techniques and Histologic Tissue Analysis CARDIOVASCULAR AND INTERVENTIONAL RADIOLOGY Kuo, W. T., Cupp, J. S., Louie, J. D., Kothary, N., Hofmann, L. V., Sze, D. Y., Hovsepian, D. M. 2012; 35 (3): 588-597

    Abstract

    We evaluated the safety and effectiveness of alternative endovascular methods to retrieve embedded optional and permanent filters in order to manage or reduce risk of long-term complications from implantation. Histologic tissue analysis was performed to elucidate the pathologic effects of chronic filter implantation.We studied the safety and effectiveness of alternative endovascular methods for removing embedded inferior vena cava (IVC) filters in 10 consecutive patients over 12 months. Indications for retrieval were symptomatic chronic IVC occlusion, caval and aortic perforation, and/or acute PE (pulmonary embolism) from filter-related thrombus. Retrieval was also performed to reduce risk of complications from long-term filter implantation and to eliminate the need for lifelong anticoagulation. All retrieved specimens were sent for histologic analysis.Retrieval was successful in all 10 patients. Filter types and implantation times were as follows: one Venatech (1,495 days), one Simon-Nitinol (1,485 days), one Optease (300 days), one G2 (416 days), five Günther-Tulip (GTF; mean 606 days, range 154-1,010 days), and one Celect (124 days). There were no procedural complications or adverse events at a mean follow-up of 304 days after removal (range 196-529 days). Histology revealed scant native intima surrounded by a predominance of neointimal hyperplasia and dense fibrosis in all specimens. Histologic evidence of photothermal tissue ablation was confirmed in three laser-treated specimens.Complex retrieval methods can now be used in select patients to safely remove embedded optional and permanent IVC filters previously considered irretrievable. Neointimal hyperplasia and dense fibrosis are the major components that must be separated to achieve successful retrieval of chronic filter implants.

    View details for DOI 10.1007/s00270-011-0175-1

    View details for Web of Science ID 000304162700018

    View details for PubMedID 21562933

  • Endovascular Therapy for Acute Pulmonary Embolism JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kuo, W. T. 2012; 23 (2): 167-179

    Abstract

    Acute pulmonary embolism (PE) is the third most common cause of death among hospitalized patients. Treatment escalation beyond anticoagulation therapy is necessary in patients with massive PE (defined by hemodynamic shock) as well as in many patients with submassive PE (defined by right ventricular strain). The best current evidence suggests that modern catheter-directed therapy to achieve rapid central clot debulking should be considered as an early or first-line treatment option for patients with acute massive PE; and emerging evidence suggests a catheter-directed thrombolytic infusion should be considered as adjunctive therapy for many patients with acute submassive PE. This article reviews the current approach to endovascular therapy for acute PE in the context of appropriate diagnosis, risk stratification, and management of acute massive and acute submassive PE.

    View details for DOI 10.1016/j.jvir.2011.10.012

    View details for Web of Science ID 000299656600003

    View details for PubMedID 22192633

  • Photothermal Ablation with the Excimer Laser Sheath Technique for Embedded Inferior Vena Cava Filter Removal: Initial Results from a Prospective Study JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kuo, W. T., Odegaard, J. I., Louie, J. D., Sze, D. Y., Unver, K., Kothary, N., Rosenberg, J. K., Hovsepian, D. M., Hwang, G. L., Hofmann, L. V. 2011; 22 (6): 813-823

    Abstract

    To evaluate the safety and effectiveness of the excimer laser sheath technique for removing embedded inferior vena cava (IVC) filters.Over 12 months, 25 consecutive patients undergoing attempted IVC filter retrieval with a laser-assisted sheath technique were prospectively enrolled into an institutional review board-approved study registry. There were 10 men and 15 women (mean age 50 years, range 20-76 years); 18 (72%) of 25 patients were referred from an outside hospital. Indications for retrieval included symptomatic filter-related acute caval thrombosis (with or without acute pulmonary embolism), chronic IVC occlusion, and bowel penetration. Retrieval was also performed to remove risks from prolonged implantation and potentially to eliminate need for lifelong anticoagulation. After failure of standard methods, controlled photothermal ablation of filter-adherent tissue with a Spectranetics laser sheath and CVX-300 laser system was performed. All patients were evaluated with cavography, and specimens were sent for histologic analysis.Laser-assisted retrieval was successful in 24 (96%) of 25 patients as follows: 11 Günther Tulip (mean 375 days, range 127-882 days), 4 Celect (mean 387 days, range 332-440 days), 2 Option (mean 215 days, range 100-330 days), 4 OPTEASE (mean 387 days, range 71-749 days; 1 failed 188 days), 2 TRAPEASE (mean 871 days, range 187-1,555 days), and 2 Greenfield (mean 12.8 years, range 7.2-18.3 years). There was one (4%) major complication (acute thrombus, treated with thrombolysis), three (12%) minor complications (small extravasation, self-limited), and one adverse event (coagulopathic retroperitoneal hemorrhage) at follow-up (mean 126 days, range 13-302 days). Photothermal ablation of filter-adherent tissue was histologically confirmed in 23 (92%) of 25 patients.The laser-assisted sheath technique appears to be a safe and effective tool for retrieving embedded IVC filters, including permanent types, with implantation ranging from months to > 18 years.

    View details for DOI 10.1016/j.jvir.2011.01.459

    View details for Web of Science ID 000291414500011

    View details for PubMedID 21530309

  • The Excimer Laser Sheath Technique for Embedded Inferior Vena Cava Filter Removal JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kuo, W. T., Cupp, J. S. 2010; 21 (12): 1896-1899

    Abstract

    An inferior vena cava (IVC) filter became embedded within the IVC of a 45-year-old man after prolonged implantation. Because of incorporation of the filter legs within the caval endothelium, the filter was densely adherent and could not be sheathed using standard retrieval methods. In this patient, the authors performed percutaneous filter retrieval using an excimer laser sheath technique for circumferential ablation of dense fibrotic tissue between the filter and IVC. Endovascular laser ablation allowed facile separation of the filter from the IVC, without tearing of the tissues, and the filter was removed successfully without complication.

    View details for DOI 10.1016/j.jvir.2010.08.013

    View details for Web of Science ID 000285372600017

    View details for PubMedID 21050774

  • Optimizing endovascular therapy for acute PE: primum non nocere. J Vasc Interv Radiol Kuo WT, Hofmann LV 2010; 21 (11): 1776-1777
  • High-risk Retrieval of Adherent and Chronically Implanted IVC Filters: Techniques for Removal and Management of Thrombotic Complications JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kuo, W. T., Tong, R. T., Hwang, G. L., Louie, J. D., Lebowitz, E. A., Sze, D. Y., Hofmann, L. V. 2009; 20 (12): 1548-1556

    Abstract

    To evaluate the safety and efficacy of aggressive techniques for retrieving adherent and chronically implanted inferior vena cava (IVC) filters.A single-center retrospective review was performed on all patients who underwent attempted filter retrieval from October 2007 through October 2008. Patients were included in the study if they had an adherent filter, refractory to standard retrieval techniques, and underwent high-risk retrieval after procedural risks were deemed lower than risks of long-term filter implantation.Fourteen patients were diagnosed with an adherent filter, 13 (93%) of whom were candidates for high-risk retrieval. These patients included seven men and six women (mean age, 40 years; age range, 18-71 years). Nine of the 13 patients (69%) were referred from an outside hospital. Filter retrieval was performed for the following indications: to avoid the risk of long-term thrombotic complications in a young patient (n= 6), to treat symptomatic filter-related IVC stenosis (n= 5), to treat symptomatic filter penetration (n= 1), and to avoid the need for lifelong anticoagulation (n= 1). There were eight Günther-Tulip filters (mean dwell time, 356 days; range 53-1,181 days), two Optease filters (mean dwell time, 62 days; range, 52-72 days), one G2 filter (dwell time, 420 days), and two Recovery filters (mean dwell time, 1,630 days; range, 1,429-1,830 days). Three IVC occlusions necessitated recanalization to facilitate retrieval. High-risk retrieval with use of various techniques with aggressive force was successful in all 13 patients (100%). Partial caval thrombosis occurred in the first four patients (31%) but did not occur after procedural modifications were implemented. There were no complications at clinical follow-up (mean, 221 days; range, 84-452 days).Alternative techniques can be used to retrieve adherent IVC filters implanted for up to 3-5 years. Although caval thrombosis was an observed complication, protocol modifications appeared to reduce this risk.

    View details for DOI 10.1016/j.jvir.2009.08.024

    View details for Web of Science ID 000272636200005

    View details for PubMedID 19864160

  • Catheter-directed Therapy for the Treatment of Massive Pulmonary Embolism: Systematic Review and Meta-analysis of Modem Techniques JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kuo, W. T., Gould, M. K., Louie, J. D., Rosenberg, J. K., Sze, D. Y., Hofmann, L. V. 2009; 20 (11): 1431-1440

    Abstract

    Systemic thrombolysis for the treatment of acute pulmonary embolism (PE) carries an estimated 20% risk of major hemorrhage, including a 3%-5% risk of hemorrhagic stroke. The authors used evidence-based methods to evaluate the safety and effectiveness of modern catheter-directed therapy (CDT) as an alternative treatment for massive PE.The systematic review was initiated by electronic literature searches (MEDLINE, EMBASE) for studies published from January 1990 through September 2008. Inclusion criteria were applied to select patients with acute massive PE treated with modern CDT. Modern techniques were defined as the use of low-profile devices (< or =10 F), mechanical fragmentation and/or aspiration of emboli including rheolytic thrombectomy, and intraclot thrombolytic injection if a local drug was infused. Relevant non-English language articles were translated into English. Paired reviewers assessed study quality and abstracted data. Meta-analysis was performed by using random effects models to calculate pooled estimates for complications and clinical success rates across studies. Clinical success was defined as stabilization of hemodynamics, resolution of hypoxia, and survival to hospital discharge.Five hundred ninety-four patients from 35 studies (six prospective, 29 retrospective) met the criteria for inclusion. The pooled clinical success rate from CDT was 86.5% (95% confidence interval [CI]: 82.1%, 90.2%). Pooled risks of minor and major procedural complications were 7.9% (95% CI: 5.0%, 11.3%) and 2.4% (95% CI: 1.9%, 4.3%), respectively. Data on the use of systemic thrombolysis before CDT were available in 571 patients; 546 of those patients (95%) were treated with CDT as the first adjunct to heparin without previous intravenous thrombolysis.Modern CDT is a relatively safe and effective treatment for acute massive PE. At experienced centers, CDT should be considered as a first-line treatment for patients with massive PE.

    View details for DOI 10.1016/j.jvir.2009.08.002

    View details for Web of Science ID 000271359000004

    View details for PubMedID 19875060

  • Catheter-directed embolectomy, fragmentation, and thrombolysis for the treatment of massive pulmonary embolism after failure of systemic thrombolysis CHEST Kuo, W. T., Van den Bosch, M. A., Hofmann, L. V., Louie, J. D., Kothary, N., Sze, D. Y. 2008; 134 (2): 250-254

    Abstract

    The standard medical management for patients in extremis from massive pulmonary embolism (PE) is systemic thrombolysis, but the utility of this treatment relative to catheter-directed intervention (CDI) is unknown. We evaluated the effectiveness of CDI as part of a treatment algorithm for life-threatening PE.A retrospective review was performed on 70 consecutive patients with suspected acute PE over a 10-year period (from 1997 to 2006) who had been referred for pulmonary angiography and/or intervention. The criteria for study inclusion were patients who received CDI due to angiographically confirmed massive PE and hemodynamic shock (shock index, > or = 0.9). CDI involved suction embolectomy and fragmentation with or without catheter thrombolysis.Twelve patients were treated with CDI. There were seven men and five women (mean age, 56 years; age range, 21 to 80 years). Seven patients (58%) were referred for CDI after failing systemic infusion with 100 mg of tissue plasminogen activator, and five patients (42%) had contraindications to systemic thrombolysis. Catheter-directed fragmentation and embolectomy were performed in all patients (100%). Additionally, catheter-guided thrombolysis was performed in eight patients (67%). Technical success was achieved in 12 of 12 cases (100%). There were no major procedural complications (0%). Significant hemodynamic improvement (shock index, < 0.9) was observed in 10 of 12 cases (83%). The remaining two patients (17%) died secondary to cardiac arrest within 24 h. Ten of 12 patients (83%) survived and remained stable until hospital discharge (mean duration, 20 days; range, 3 to 51 days).In the setting of hemodynamic shock from massive PE, CDI is potentially a life-saving treatment for patients who have not responded to or cannot tolerate systemic thrombolysis.

    View details for DOI 10.1378/chest.07-2846

    View details for Web of Science ID 000258492500008

    View details for PubMedID 18682455

  • Wire loop methods for retrieval of trapped inferior vena cava filters: 10-F versus 16-F sheath technique JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kuo, W. T., Kee, S. T. 2008; 19 (6): 956-957

    View details for DOI 10.1016/j.jvir.2007.11.028

    View details for Web of Science ID 000256416300026

    View details for PubMedID 18503917

  • Catheter-directed intervention for acute pulmonary embolism - A shining saber CHEST Kuo, W. T., Sze, D. Y., Hofmann, L. V. 2008; 133 (1): 317-318

    View details for DOI 10.1378/chest.07-2278

    View details for Web of Science ID 000252385600063

    View details for PubMedID 18187767

  • Emergency retrieval of a G2 filter after complete migration in to the right ventricle JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kuo, W. T., Loh, C. T., Sze, D. Y. 2007; 18 (9): 1177-1182

    Abstract

    A G2 inferior vena cava filter migrated completely into the right ventricle, resulting in chest pain, ventricular tachycardia, and hypotension in a 63-year-old man. Due to the filter's position, the patient was at high risk for further life-threatening cardiopulmonary complications. Percutaneous filter retrieval was successfully performed as a less-invasive alternative to open cardiothoracic surgery.

    View details for DOI 10.1016/j.jvir.2007.06.006

    View details for Web of Science ID 000249547300018

    View details for PubMedID 17804782

  • Retrieval of trapped Gunther tulip inferior vena cava filters: Snare-over-guide wire loop technique JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kuo, W. T., Bostaph, A. S., Loh, C. T., Frisoli, J. K., Kee, S. T. 2006; 17 (11): 1845-1849

    Abstract

    The Günther Tulip inferior vena cava (IVC) filter is designed for transjugular retrieval with use of a sheath and snare device. This report describes a technique for removal of difficult-to-retrieve Günther Tulip IVC filters when the standard method fails. In a series of four patients, each with an IVC filter refractory to capture by snare alone, the use of a snare-over-guide wire loop technique succeeded in retrieving the filter in all cases.

    View details for DOI 10.1097/01.RVI.0000241946.40524.85

    View details for Web of Science ID 000242482400016

    View details for PubMedID 17142717

  • Transcatheter treatment for lower gastrointestinal hemorrhage. Techniques in vascular and interventional radiology Kuo, W. T. 2004; 7 (3): 143-150

    Abstract

    Modern transcatheter embolization has emerged as a viable option for the treatment of lower gastrointestinal (LGI) hemorrhage. Over the last decade, steady data has accumulated showing the safety and effectiveness of superselective microcoil embolization within the colon. In light of such results, the application of microcatheter-based skills has become more important in an algorithm for managing LGI bleeding. The purpose of this article is to discuss the modern embolization technique while also reviewing traditional and experimental transcatheter methods that may prove useful in the appropriate clinical settings. While recognizing that transcatheter therapy continues to evolve, the proposed indications for these current treatments are reviewed.

    View details for PubMedID 16015559

  • Superselective microcoil embolization for the treatment of lower gastrointestinal hemorrhage JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kuo, W. T., Lee, D. E., Saad, W. E., Patel, N., Sahler, L. G., Waldman, D. L. 2003; 14 (12): 1503-1509

    Abstract

    To evaluate the safety and effectiveness of superselective microcoil embolization for the treatment of lower gastrointestinal (LGI) hemorrhage.A retrospective review of LGI superselective microcoil embolization data for a 10-year period was performed. During this period, twenty-two patients with evidence on angiography of LGI bleeding underwent superselective microcoil embolization. Hemorrhage was treated in the colon (n = 19) and jejunum (n = 3). Ivalon was used adjunctively in two patients and gelfoam was used as a secondary agent in two additional patients. Postembolization ischemia was evaluated objectively in 14 patients by colonoscopy (n = 10), surgical specimen (n = 3), and barium enema (n = 1). All patients were followed for clinical evidence of bowel ischemia. Four patients died before further follow-up could be performed. Additionally, 122 cases of LGI hemorrhage treated with superselective microcoil embolization were identified in a review of the literature. A meta-analysis was then performed, combining the data in this study and the data from the literature, to estimate the rate of major and minor ischemic complications on a total of 144 superselective microcoil embolizations.Immediate hemostasis was achieved in all 22 patients in this study. Complete clinical success was achieved in 86% of patients (19 of 22 patients). Rebleeding occurred in 14% of patients (3 of 22 patients) and each underwent colonoscopic intervention with success. Postembolization objective follow-up was performed in 64% of patients (14 of 22 patients). Ten patients underwent follow-up colonoscopy; one patient received a follow-up barium enema; and three patients underwent subsequent surgery. Colonic resection (one partial and one total) was performed in two patients. The partial colectomy was performed in a patient who had been diagnosed with colonic polyps and dysplasia. The total colectomy was performed on a patient with history of chronic LGI bleeding complicated by long-term anticoagulation therapy and a history of tubular adenoma resection. The third surgical patient (16 months old) underwent a follow-up exploratory laparotomy after embolization of a proximal jejunal branch of the superior mesenteric artery. None of the three patients who underwent surgery were found to have postembolic ischemic changes in the bowel specimen. Four patients in this study died, for reasons unrelated to hemorrhage or embolization, before further follow-up could be performed. The last four patients were followed clinically and experienced no symptoms of intestinal ischemia. A minor ischemic complication was reported in 4.5% of patients (1 of 22 patients), and there were no major ischemic complications (0%) in this series. A review of the data from 122 cases of LGI superselective microcoil embolization in the literature is also presented. Combined with the data in this study, the minor complication rate was 9% (13 of 144 patients), and the major complication rate was 0% (0 of 144 patients).Superselective microcoil embolization is a safe and effective treatment for LGI hemorrhage.

    View details for DOI 10.1097/01.RV1.0000099780.23569.E6

    View details for Web of Science ID 000220021900004

    View details for PubMedID 14654483

  • Correlation of the Diameter of the Left Common Iliac Vein with the Risk of Lower-extremity Deep Venous Thrombosis JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Carr, S., Chan, K., Rosenberg, J., Kuo, W. T., Kothary, N., Hovsepian, D. M., Sze, D. Y., Hofmann, L. V. 2012; 23 (11): 1467-1472

    Abstract

    Compression of the left common iliac vein (CIV; LCIV) is a known risk factor for lower-extremity deep vein thrombosis (DVT). This study was performed to model the probability of DVT based on LCIV diameter and apply this to a quantitative DVT risk factor scoring system.Medical records were used to identify female patients younger than 45 years of age who were diagnosed with lower-extremity DVT (n = 21) and age-matched control subjects (n = 26) who presented to the emergency department with abdominal pain. Minimum CIV diameters were measured on computed tomography. Based on published reporting standards, 13 risk factors were scored for patients diagnosed with left-sided DVT and for control subjects. The association between vein diameter and DVT was examined by Mann-Whitney test. Odds of DVT based on vein diameter was assessed by logistic regression.Mean minimum LCIV diameters were 4.0 mm for patients with DVT and 6.5 mm for patients without DVT (P = .001). The odds of left DVT increased by a factor of 1.68 for each millimeter decrease in LCIV diameter (odds ratio = 1.68; P = .006; 95% confidence interval, 1.16-2.43). As the risk factor score increased, the relationship between diameter and risk for DVT became stronger; identical LCIV diameters were associated wtih a higher probability of developing DVT if the risk factor score was higher.Stenosis of the LCIV was found to be a strong independent risk factor for development of DVT. Moreover, each millimeter decrease in CIV diameter increased the odds of DVT by a factor of 1.68.

    View details for DOI 10.1016/j.jvir.2012.07.030

    View details for Web of Science ID 000311267900011

    View details for PubMedID 23101919

  • Applying a Structured Innovation Process to Interventional Radiology: A Single-Center Experience JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Sista, A. K., Hwang, G. L., Hovsepian, D. M., Sze, D. Y., Kuo, W. T., Kothary, N., Louie, J. D., Yamada, K., Hong, R., Dhanani, R., Brinton, T. J., Krummel, T. M., Makower, J., Yock, P. G., Hofmann, L. V. 2012; 23 (4): 488-494

    Abstract

    To determine the feasibility and efficacy of applying an established innovation process to an active academic interventional radiology (IR) practice.The Stanford Biodesign Medical Technology Innovation Process was used as the innovation template. Over a 4-month period, seven IR faculty and four IR fellow physicians recorded observations. These observations were converted into need statements. One particular need relating to gastrostomy tubes was diligently screened and was the subject of a single formal brainstorming session.Investigators collected 82 observations, 34 by faculty and 48 by fellows. The categories that generated the most observations were enteral feeding (n = 9, 11%), biopsy (n = 8, 10%), chest tubes (n = 6, 7%), chemoembolization and radioembolization (n = 6, 7%), and biliary interventions (n = 5, 6%). The output from the screening on the gastrostomy tube need was a specification sheet that served as a guidance document for the subsequent brainstorming session. The brainstorming session produced 10 concepts under three separate categories.This formalized innovation process generated numerous observations and ultimately 10 concepts to potentially to solve a significant clinical need, suggesting that a structured process can help guide an IR practice interested in medical innovation.

    View details for DOI 10.1016/j.jvir.2011.12.029

    View details for Web of Science ID 000302396300009

    View details for PubMedID 22464713

  • Catheter-directed thrombolysis for acute DVT LANCET Hofmann, L. V., Kuo, W. T. 2012; 379 (9810): 3-4
  • Applying a structured innovation process to interventional radiology: a single center's experience J Vasc Interv Radiol Sista AK, Hwang GL, Hovsepian DH, Kuo WT, et al 2012
  • Percutaneous Cholecystostomy for Acute Cholecystitis: Ten-Year Experience JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Joseph, T., Unver, K., Hwang, G. L., Rosenberg, J., Sze, D. Y., Hashimi, S., Kothary, N., Louie, J. D., Kuo, W. T., Hofmann, L. V., Hovsepian, D. M. 2012; 23 (1): 83-88

    Abstract

    To review the clinical course of patients with acute cholecystitis treated by percutaneous cholecystostomy, and to identify risk factors retrospectively that predict outcome.A total of 106 patients diagnosed with acute cholecystitis were treated by percutaneous cholecystostomy during a 10-year period. Seventy-one (67%) presented to the emergency department (ED) specifically for acute cholecystitis, and 35 (23%) were inpatients previously admitted for other conditions. Outcomes of the two groups were compared with respect to severity of illness, leukocytosis, bile culture, liver function tests, imaging features, time intervals from onset of symptoms to medical and percutaneous intervention, and whether surgical cholecystectomy was later performed.Overall, 72 patients (68%) showed an improvement clinically, whereas 34 (32%) showed no improvement or a clinically worsened condition after cholecystostomy. Patients who presented to the ED primarily with acute cholecystitis fared better (84% of patients showed improvement) than inpatients (34% showed improvement; P < .0001). Gallstones were identified in 54% of patients who presented to the ED, whereas acalculous cholecystitis was more commonly diagnosed in inpatients (54%). Patients with sepsis had worse outcomes overall (P < .0001). Bacterial bile cultures were analyzed in 95% of patients and showed positive results in 52%, with no overall effect on outcome. There was no correlation between the time of onset of symptoms until antibiotic therapy or cholecystostomy in either group. Long-term outcomes for both groups were better for those who later underwent cholecystectomy (P < .0001).Outcomes after percutaneous cholecystostomy for acute cholecystitis are better when the disease is primary and not precipitated by concurrent illness.

    View details for DOI 10.1016/j.jvir.2011.09.030

    View details for Web of Science ID 000299151400015

    View details for PubMedID 22133709

  • Imaging Guidance with C-arm CT: Prospective Evaluation of Its Impact on Patient Radiation Exposure during Transhepatic Arterial Chemoembolization JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kothary, N., Abdelmaksoud, M. H., Tognolini, A., Fahrig, R., Rosenberg, J., Hovsepian, D. M., Ganguly, A., Louie, J. D., Kuo, W. T., Hwang, G. L., Holzer, A., Sze, D. Y., Hofmann, L. V. 2011; 22 (11): 1535-1544

    Abstract

    To prospectively evaluate the impact of C-arm CT on radiation exposure to hepatocellular carcinoma (HCC) patients treated by chemoembolization.Patients with HCC (N = 87) underwent digital subtraction angiography (DSA; control group) or combined C-arm CT/DSA (test group) for chemoembolization. Dose-area product (DAP) and cumulative dose (CD) were measured for guidance and treatment verification. Contrast agent volume and C-arm CT utility were also measured.The marginal DAP increase in the test group was offset by a substantial (50%) decrease in CD from DSA. Use of C-arm CT allowed reduction of DAP and CD from DSA imaging (P = .007 and P = .017). Experienced operators were more efficient in substituting C-arm CT for DSA, resulting in a negligible increase (7.5%) in total DAP for guidance, compared with an increase of 34% for all operators (P = .03). For treatment verification, DAP from C-arm CT exceeded that from DSA, approaching that of conventional CT. The test group used less contrast medium (P = .001), and C-arm CT provided critical or supplemental information in 20% and 17% of patients, respectively.Routine use of C-arm CT can increase stochastic risk (DAP) but decrease deterministic risk (CD) from DSA. However, the increase in DAP is operator-dependent, thus, with experience, it can be reduced to under 10%. C-arm CT provides information not provided by DSA in 33% of patients, while decreasing the use of iodinated contrast medium. As with all radiation-emitting modalities, C-arm CT should be used judiciously.

    View details for DOI 10.1016/j.jvir.2011.07.008

    View details for Web of Science ID 000296661800008

    View details for PubMedID 21875814

  • Embolization of Parasitized Extrahepatic Arteries to Reestablish Intrahepatic Arterial Supply to Tumors before Yttrium-90 Radioembolization JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Abdelmaksoud, M. H., Louie, J. D., Kothary, N., Hwang, G. L., Kuo, W. T., Hofmann, L. V., Hovsepian, D. M., Sze, D. Y. 2011; 22 (10): 1355-1362

    Abstract

    To perform embolization of parasitized extrahepatic arteries (EHAs) before radioembolization to reestablish intrahepatic arterial supply to large, peripheral tumors, and to evaluate the technical and clinical outcomes of this intervention.Among 201 patients retrospectively analyzed, embolization of 73 parasitized EHAs in 35 patients was performed. Most embolization procedures were performed during preparatory angiography using large particles and coils. Digital subtraction angiography (DSA), C-arm computed tomography (CT), and technetium-99m macroaggregated albumin ((99m)TcMAA) scintigraphy were used to evaluate the immediate perfusion via intrahepatic collateral channels of target tumor areas previously supplied by parasitized EHAs. Follow-up imaging of differential regional tumor response was used to evaluate microsphere distribution and clinical outcome.After embolization, reestablishment of intrahepatic arterial supply was confirmed by both DSA and C-arm CT in 94% of territories and by scintigraphy in 96%. In 32% of patients, the differential response of treatment could not be evaluated because of uniform disease progression. However, symmetric regional tumor response in 94% of evaluable patients indicated successful delivery of microspheres to the territories previously supplied by parasitized EHAs.Reestablishment of intrahepatic arterial inflow to hepatic tumors by embolization of parasitized EHAs is safe and effective and results in successful delivery of yttrium-90 microspheres to tumors previously perfused by parasitized EHAs.

    View details for DOI 10.1016/j.jvir.2011.06.007

    View details for Web of Science ID 000295708400002

    View details for PubMedID 21961979

  • Consolidation of Hepatic Arterial Inflow by Embolization of Variant Hepatic Arteries in Preparation for Yttrium-90 Radioembolization JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Abdelmaksoud, M. H., Louie, J. D., Kothary, N., Hwang, G. L., Kuo, W. T., Hofmann, L. V., Hovsepian, D. M., Sze, D. Y. 2011; 22 (10): 1364-1372

    Abstract

    Before yttrium-90 ((90)Y) radioembolization administration, the authors consolidated arterial inflow by embolizing variant hepatic arteries (HAs) to make microsphere delivery simpler and safer. The present study reviews the technical and clinical success of these consolidation procedures.Preparatory and treatment angiograms were retrospectively analyzed for 201 patients. Variant HAs were coil-embolized during preparatory angiography to simplify arterial anatomy. Collateral arterial perfusion of territories previously supplied by variant HAs was evaluated by digital subtraction angiography (DSA), C-arm computed tomography (CT), and technetium-99m ((99m)Tc)-macroaggregated albumin (MAA) scintigraphy, and by follow-up evaluation of regional tumor response.A total of 47 variant HAs were embolized in 43 patients. After embolization of variant HAs, cross-perfusion into the embolized territory was depicted by DSA and by C-arm CT in 100% of patients and by (99m)Tc-MAA scintigraphy in 92.7%. Uniform progressive disease prevented evaluation in 33% of patients, but regional tumor response in patients who responded supported successful delivery of microspheres to the embolized territories in 95.5% of evaluable patients.Embolization of variant HAs for consolidation of hepatic supply in preparation for (90)Y radioembolization promotes treatment of affected territories via intrahepatic collateral channels.

    View details for DOI 10.1016/j.jvir.2011.06.014

    View details for Web of Science ID 000295708400004

    View details for PubMedID 21961981

  • Portal Venous Remodeling After Endovascular Reduction of Pediatric Autogenous Portosystemic Shunts JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Stewart, J. K., Kuo, W. T., Hovsepian, D. M., Hofmann, L. V., Bonham, C. A., Sze, D. Y. 2011; 22 (8): 1199-1205

    Abstract

    Patients with autogenous native vessel portosystemic shunts, whether surgical or congenital, may experience complications of excess shunt flow, including hepatopulmonary syndrome (HPS), hepatic encephalopathy (HE), and hepatic insufficiency. The authors explored endovascular reduction or occlusion of autogenous portosystemic shunts using methods commonly employed in transjugular intrahepatic portosystemic shunt (TIPS) reduction in four pediatric patients. Before treatment, the patients had hypoplastic, atrophic, or thrombosed portal veins. Following intervention, symptoms of overshunting resolved or improved in all patients without major complications. The innate plasticity of the pediatric portal venous system allowed for hypertrophy or development and maturation of cavernous transformations to accommodate increased hepatopetal blood flow and pressure.

    View details for DOI 10.1016/j.jvir.2011.01.438

    View details for Web of Science ID 000293482700020

    View details for PubMedID 21801995

  • Intrahepatic Collateral Supply to the Previously Embolized Right Gastric Artery: A Potential Pitfall for Nontarget Radioembolization JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Meer, A. B., Louie, J. D., Abdelmaksoud, M. H., Kothary, N., Hovsepian, D. M., Hofmann, L. V., Kuo, W. T., Hwang, G. L., Sze, D. Y. 2011; 22 (4): 575-577

    View details for DOI 10.1016/j.jvir.2010.12.031

    View details for Web of Science ID 000289340100024

    View details for PubMedID 21463762

  • Common Iliac Vein Stenosis and Risk of Symptomatic Pulmonary Embolism: An Inverse Correlation JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Chan, K. T., Popat, R. A., Sze, D. Y., Kuo, W. T., Kothary, N., Louie, J. D., Hovsepian, D. M., Hwang, G. L., Hofmann, L. V. 2011; 22 (2): 133-141

    Abstract

    To test the hypothesis that a common iliac vein (CIV) stenosis may impair embolization of a large deep venous thrombosis (DVT) to the lungs, decreasing the incidence of a symptomatic pulmonary embolism (PE).Between January 2002 and August 2007, 75 patients diagnosed with unilateral DVT were included in a single-institution case-control study. Minimum CIV diameters were measured 1 cm below the inferior vena cava (IVC) bifurcation on computed tomography (CT) images. A significant stenosis in the CIV ipsilateral to the DVT was defined as having either a diameter 4 mm or less or a greater than 70% reduction in lumen diameter. A symptomatic PE was defined as having symptoms and imaging findings consistent with a PE. The odds of symptomatic PE versus CIV stenosis were assessed using logistic regression models. The associations between thrombus location, stenosis, and symptomatic PE were assessed using a stratified analysis.Of 75 subjects, 49 (65%) presented with symptomatic PE. There were 17 (23%) subjects with a venous lumen 4 mm or less and 12 (16%) subjects with a greater than 70% stenosis. CIV stenosis of 4 mm or less resulted in a decreased odds of a symptomatic PE compared with a lumen greater than 4 mm (odds ratio [OR] 0.17, P = .011), whereas a greater than 70% stenosis increased the odds of DVT involving the CIV (OR 7.1, P = .047).Among patients with unilateral DVT, those with an ipsilateral CIV lumen of 4 mm or less have an 83% lower risk of developing symptomatic PE compared with patients with a CIV lumen greater than 4 mm.

    View details for DOI 10.1016/j.jvir.2010.10.009

    View details for Web of Science ID 000287166600004

    View details for PubMedID 21276911

  • Renewing Focus on Resident Education: Increased Responsibility and Ownership in Interventional Radiology Rotations Improves the Educational Experience JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kothary, N., Ghatan, C. E., Hwang, G. L., Kuo, W. T., Louie, J. D., Sze, D. Y., Hovsepian, D. M., Desser, T. S., Hofmann, L. V. 2010; 21 (11): 1697-1702

    Abstract

    To enhance the educational experience among residents rotating through interventional radiology (IR) by encouraging ownership and responsibility.In May 2006, the authors implemented changes in resident education in IR that included increased clinical responsibilities, structured didactics, and greater hands-on experience, including call. Residents were assigned as first assistants, ownership of cases was encouraged, and assignment to a week on the consult service was instituted to help residents better understand all aspects of IR practice. Additional faculty recruitment and program expansion ensured the same high level of training for the fellowship program. Evaluations were reviewed every year (July 1, 2007-June 30, 2009) for hands-on training, daily teaching, didactic conferences, and overall effectiveness of the clinical service. A graduated scale of 1-5 was used.In 2009, 3 years after the curricular changes were made, the quality of hands-on training, daily case reviews and consults, didactics, and overall education had markedly improved with 89%, 71%, 65%, and 82% of the residents rating these respective aspects of the training as "above expectations" (4 on a scale of 5) or "superior" (5 on a scale of 5) compared with 77%, 23%, 20%, and 60% in 2005-2006. Three years after the changes, the impact of these changes on recruitment patterns also showed improvement, with 28.6% of the class of 2010 pursuing a fellowship in IR.Increasing resident ownership, responsibility, and hands-on experience improves resident education in IR, which, in turn, promotes interest in the field.

    View details for DOI 10.1016/j.jvir.2010.07.009

    View details for Web of Science ID 000284244200009

    View details for PubMedID 20884234

  • Angiojet Rheolytic Thrombectomy in Massive Pulmonary Embolism Locally Efficacious but Systemically Deleterious? Response JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kuo, W. T., Hofmann, L. V. 2010; 21 (11): 1776-1777
  • Development of New Hepaticoenteric Collateral Pathways after Hepatic Arterial Skeletonization in Preparation for Yttrium-90 Radioembolization JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Abdelmaksoud, M. H., Hwang, G. L., Louie, J. D., Kothary, N., Hofmann, L. V., Kuo, W. T., Hovsepian, D. M., Sze, D. Y. 2010; 21 (9): 1385-1395

    Abstract

    Development of new hepaticoenteric anastomotic vessels may occur after endovascular skeletonization of the hepatic artery. Left untreated, they can serve as pathways for nontarget radioembolization. The authors reviewed the incidence, anatomy, management, and significance of collateral vessel formation in patients undergoing radioembolization.One hundred thirty-eight treatments performed on 122 patients were reviewed. Each patient underwent a preparatory digital subtraction angiogram (DSA) and embolization of all hepaticoenteric vessels in preparation for yttrium-90 ((90)Y) administration. Successful skeletonization was verified by C-arm computed tomography (CACT) and technetium-99m macroaggregated albumin ((99m)TcMAA) scintigraphy. During the subsequent treatment session, DSA and CACT were repeated before administration of (90)Y, and the detection of extrahepatic perfusion prompted additional embolization.Forty-two patients (34.4%) undergoing 43 treatments (31.2%) required adjunctive embolization of hepaticoenteric vessels immediately before (90)Y administration. Previous scintigraphy findings showed extrahepatic perfusion in only three cases (7.1%). Vessels were identified by DSA in 54.1%, by CACT in 4.9%, or required both in 41.0%. The time interval between angiograms did not correlate with risk of requiring reembolization (P = .297). A total of 19.7% of vessels were new collateral vessels not visible during the initial angiography. Despite reembolization, three patients (7.1%) had gastric or duodenal ulceration, compared with 1.3% who never had visible collateral vessels, all of whom underwent whole-liver treatment with resin microspheres (P = .038).Development of collateral hepaticoenteric anastomoses occurs after endovascular skeletonization of the hepatic artery. Identified vessels may be managed by adjunctive embolization, but patients appear to remain at increased risk for gastrointestinal complications.

    View details for DOI 10.1016/j.jvir.2010.04.030

    View details for Web of Science ID 000281620600012

    View details for PubMedID 20688531

  • Computed Tomography-Guided Percutaneous Needle Biopsy of Indeterminate Pulmonary Pathology: Efficacy of Obtaining a Diagnostic Sample in Immunocompetent and Immunocompromised Patients CLINICAL LUNG CANCER Kothary, N., Bartos, J. A., Hwang, G. L., Dua, R., Kuo, W. T., Hofmann, L. V. 2010; 11 (4): 251-256

    Abstract

    We aimed to evaluate the efficacy of computed tomography (CT)-guided percutaneous lung biopsy of pulmonary nodules with indeterminate radiologic characteristics in patients at risk for malignant and nonmalignant processes such as infection or inflammation.From January 2003 to September 2008, 262 patients (mean age, 59 years; range, 18-92 years) with pulmonary nodules or a mass of uncertain etiology and with indeterminate radiologic characteristics underwent CT-guided percutaneous lung biopsy. Patients with discordant clinical history and imaging findings or immunocompromised patients at risk for both etiologies were included. Specimens were submitted for both cytology and microbiology.Of the entire cohort, 166 patients (63.4%) had a nonmalignant process, and 96 patients (36.6%) had a malignancy. CT-guided percutaneous lung biopsy established a diagnosis in 166 patients (63.4%). Of the 166 patients with a nonmalignant etiology and 96 patients with malignancy, it provided a definitive diagnosis in 91 patients (54.8%) and 75 patients (78.1%), respectively, a difference that was statistically significant (P = .0001). Overall diagnostic efficacy between immunocompetent and immunocompromised patients was comparable (P = .2); however, detection of infection or inflammation in individual groups was lower compared with detection of malignancy (P = .002 and P = .06, respectively).CT-guided percutaneous lung biopsy in patients who are clinically at risk for both nonmalignant and malignant processes continues to be a challenge. Although CT-guided percutaneous biopsy can establish an accurate diagnosis in a large majority of patients with malignancy, it is significantly less sensitive for infectious or inflammatory processes.

    View details for DOI 10.3816/CLC.2010.n.032

    View details for Web of Science ID 000279496400006

    View details for PubMedID 20630827

  • Making the Case for Early Medical Student Education in Interventional Radiology: A Survey of 2nd-year Students in a Single US Institution JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Ghatan, C. E., Kuo, W. T., Hofmann, L. V., Kothary, N. 2010; 21 (4): 549-553

    Abstract

    To examine perceptions of interventional radiology (IR) among a group of second-year medical students and support the case for early exposure to the field in order to increase visibility and, ultimately, recruitment to this specialty.Sixty-five members of the class of 2011 from a single U.S. institution were anonymously surveyed about their opinions on IR before and after a 1-hour case-based introductory lecture.Sixty-four students completed the survey in its entirety. Perception about what IR entails varied, with 52% of the students aware of IR involvement in major and potentially life-saving procedures; however, 34% believed that an interventional radiologist primarily performed "minor" procedures or "read films." Previous interaction with interventional radiologists was uncommon. Following the single, case-based introductory IR lecture, 74% of the class was eager to learn more about the specialty, with 22% interested in enrolling in a dedicated hands-on elective in IR. The perception and impression of what IR entails changed significantly for the better for 75% of the students. Before the lecture, 19% were considering IR as a career (first or second choice); this increased to 33% after the introductory lecture.Although medical students are aware of IR, their exposure and understanding is limited. They are keen to learn more when exposed to it. Reaching out to the medical students early in their career may help in recruiting talent and securing the specialty's growth.

    View details for DOI 10.1016/j.jvir.2009.12.397

    View details for Web of Science ID 000276663700019

    View details for PubMedID 20189831

  • Reporting Standards for Endovascular Treatment of Pulmonary Embolism JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Banovac, F., Buckley, D. C., Kuo, W. T., Lough, D. M., Martin, L. G., Millward, S. F., Clark, T. W., Kundu, S., Rajan, D. K., Sacks, D., Cardella, J. F. 2010; 21 (1): 44-53

    View details for DOI 10.1016/j.jvir.2009.09.018

    View details for Web of Science ID 000277367500004

    View details for PubMedID 20123190

  • Incorporating Cone-beam CT into the Treatment Planning for Yttrium-90 Radioembolization JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Louie, J. D., Kothary, N., Kuo, W. T., Hwang, G. L., Hofmann, L. V., Goris, M. L., Iagaru, A. H., Sze, D. Y. 2009; 20 (5): 606-613

    Abstract

    To prepare for yttrium-90 ((90)Y) microsphere radioembolization therapy, digital subtraction angiography (DSA) and technetium- 99m-labeled macroaggregated albumin ((99m)Tc MAA) scintigraphy are used for treatment planning and detection of potential nontarget embolization. The present study was performed to determine if cone-beam computed tomography (CBCT) affects treatment planning as an adjunct to these conventional imaging modalities.From March 2007 to August 2008, 42 consecutive patients (21 men, 21 women; mean age, 59 years; range, 21-75 y) who underwent radioembolization were evaluated by CBCT in addition to DSA and (99m)Tc MAA scintigraphy during treatment planning, and their records were retrospectively reviewed. The contrast-enhanced territories shown by CBCT with selective intraarterial contrast agent administration were used to predict intrahepatic and possible extrahepatic distribution of microspheres.In 22 of 42 cases (52%), extrahepatic enhancement or incomplete tumor perfusion seen on CBCT affected the treatment plan. In 14 patients (33%), the findings were evident exclusively on CBCT and not detected by DSA. When comparing CBCT versus (99m)Tc MAA scintigraphy, CBCT showed eight cases of extrahepatic enhancement (19%) that were not evident on (99m)Tc MAA imaging. CBCT findings directed the additional embolization of vessels or repositioning of the catheter for better contrast agent and microsphere distribution. One case of gastric ulcer from nontarget embolization caused by reader error was observed.CBCT can provide additional information about tumor and tissue perfusion not currently detectable by DSA or (99m)Tc MAA imaging, which should optimize (90)Y microsphere delivery and reduce nontarget embolization.

    View details for DOI 10.1016/j.jvir.2009.01.021

    View details for Web of Science ID 000265700900007

    View details for PubMedID 19345589

  • Safety and Efficacy of Percutaneous Fiducial Marker Implantation for Image-guided Radiation Therapy JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kothary, N., Heit, J. J., Louie, J. D., Kuo, W. T., Loo, B. W., Koong, A., Chang, D. T., Hovsepian, D., Sze, D. Y., Hofmann, L. V. 2009; 20 (2): 235-239

    Abstract

    To evaluate the safety and technical success rate of percutaneous fiducial marker implantation in preparation for image-guided radiation therapy.From January 2003 to January 2008, we retrospectively reviewed 139 percutaneous fiducial marker implantations in 132 patients. Of the 139 implantations, 44 were in the lung, 61 were in the pancreas, and 34 were in the liver. Procedure-related major and minor complications were documented. Technical success was defined as implantation enabling adequate treatment planning and computed tomographic simulation.The major and minor complication rates were 5% and 17.3%, respectively. Pneumothorax after lung implantation was the most common complication. Pneumothoraces were seen in 20 of the 44 lung implantations (45%); a chest tube was required in only seven of the 44 lung transplantations (16%). Of the 139 implantations, 133 were successful; in six implantations (4.3%) the fiducial markers migrated and required additional procedures or alternate methods of implantation.Percutaneous implantation of fiducial marker is a safe and effective procedure with risks that are similar to those of conventional percutaneous organ biopsy.

    View details for DOI 10.1016/j.jvir.2008.09.026

    View details for Web of Science ID 000263075000012

    View details for PubMedID 19019700

  • The CT appearance of pleural and extrapleural disease in lymphoma CLINICAL RADIOLOGY Aquino, S. L., Chen, M. Y., Kuo, W. T., Chiles, C. 1999; 54 (10): 647-650

    Abstract

    Pleural effusions in patients with lymphoma that are assumed to be related to malignancy are attributed to either lymphatic obstruction by tumour with resultant decreased clearance of pleural fluid, or direct tumour involvement of the pleura. The purpose of our study was to determine how often pleural or extrapleural disease was detected by computed tomography (CT) of patients with pleural effusions and primary or recurrent lymphoma.We reviewed CT examinations showing evidence of pleural effusion in 61 patients with a diagnosis of primary or recurrent lymphoma and no history of other systemic disorders, including infection. The study population consisted of patients with non-Hodgkin's lymphoma (n = 44) or Hodgkin's disease (n = 17); both primary disease (n = 11) and recurrent disease (n = 50) were represented. Each CT examination was evaluated for the presence of disease involving the visceral and parietal pleura and extrapleural space, mediastinal adenopathy, and pulmonary parenchymal disease.Fourteen patients (23%) (nine with non-Hodgkin's lymphoma and five with Hodgkin's disease) had parietal pleural disease (thickening or nodules). Eighteen patients (30%) (14 with non-Hodgkin's lymphoma, four with Hodgkin's disease) had tumour or enlarged lymph nodes in the extrapleural space. Forty-three patients (70%) had mediastinal lymphadenopathy. Patients who received intravenous contrast did not have evidence of visceral pleural abnormalities or underlying pulmonary parenchymal disease.Forty-one percent of the patients with lymphoma and pleural effusions had CT evidence of pleural and/or extrapleural disease. The majority of the patients with extrapleural disease had adjacent posterior mediastinal disease.

    View details for Web of Science ID 000083137900005

    View details for PubMedID 10541388

Books and Book Chapters


  • Transjugular Intrahepatic Portosystemic Shunt Anesthesiologist's Manual of Surgical Procedures Kuo, W. T. Lippincott Williams & Wilkins. 2010
  • Mesenteric Angiography and Intervention Interventional Radiology Secrets Kuo, W. T., Saad, W. E. Hanley & Belfus. 2004
  • Ultrasound Evaluation of the Abdominal Aorta Ultrasound Secrets Kuo, W. T. Hanley & Belfus. 2004

Conference Proceedings


  • Excimer laser-assisted removal of embedded IVC filters: a single-center prospective study Kuo, W. T., et al 2013
  • Outcomes of viabil covered stent placement for treatment of hepaticojejunostomy strictures Hwang, G. L., Louie, J. D., Hofmann, L. V., Kothary, N., Kuo, W. T., Desai, J., Hovsepian, D. M., Sze, D. Y. 2013: S54
  • Complex retrieval of fractured, embedded, and penetrating IVC filters: a prospective study with histologic and electron microscopic analysis Kuo, W., et al 2012: S26-S27
  • Common iliac vein stenosis: a risk factor for oral contraceptive-induced deep vein thrombosis Chan, K. T., Tye, G. A., Popat, R. A., Kuo, W. T., Unver, K., Kothary, N., Sze, D. Y., Hofmann, L. V. MOSBY-ELSEVIER. 2011

    Abstract

    The objective of the study was to determine whether women with significant left common iliac vein stenosis who also use combined oral contraceptives (COCs) have a combined likelihood of deep vein thrombosis (DVT) greater than each independent risk.This was a case-control study comparing 35 women with DVT against 35 age-matched controls. Common iliac vein diameters were measured from computed tomography and magnetic resonance imaging. Logistic regression modeling was used with adjustment for risk factors.DVT was associated with COC use (P = .022) and with increasing degrees of common iliac vein stenosis (P = .004). Compared with women without venous stenosis or COC use, the odds of DVT in women with a 70% venous stenosis who also use COCs was associated with a 17-fold increase (P = .01).Venous stenosis and COC use are independent risk factors for DVT. Women concurrently exposed to both have a multiplicative effect resulting in an increased risk of DVT. We recommend further studies to investigate this effect and its potential clinical implications.

    View details for DOI 10.1016/j.ajog.2011.06.100

    View details for Web of Science ID 000297329200019

    View details for PubMedID 21893308

  • Photothermal ablation with the excimer laser sheath technique for embedded IVC filter removal: Initial results from a prospective study Kuo, W. T., et al 2011: S46
  • Making the case for early medical student education in interventional radiology: A survey of 2nd-year students in a single U.S. institution Ghatan, C. E., Kuo, W. T., Hofmann, L., Kothary, N. 2011: S135
  • Cholecystostomy for high risk surgical patients with acute cholecystitis: A 10 year analysis Joseph, T. M., Unver, K., Rosenberg, J., Hashmi, S., Hofmann, L., Sze, D. Y., Kothary, N., Hwang, G. L., Kuo, W. T., Louie, J. D., Hovsepian, D. M. 2011: S30
  • Retrieval of permanently-embedded IVC filters and description of the laser-assisted sheath technique: Radiographic-histopathologic correlation Kuo, W. T., et al 2010: S4
  • Impact of using c-arm CT on treatment planning for yttrium-90 radioembolization Louie, J. D., Kothary, N., Kuo, W. T., Hwang, G. L., Hofmann, L., Goris, M., Iagaru, A., Sze, D. Y. 2010: S14
  • High-Risk Retrieval of Adherent and Chronically Implanted IVC Filters: Techniques for Removal and Management of Procedural Thrombotic Complications Kuo, W. T., Tong, R., Hwang, G. L., Louie, J. D., Sze, D. Y., Morshedi, M. M., Lebowitz, E. A., Hofmann, L. V. 2009: S23
  • Iliac Vein Stenosis and Thrombus Volume: A Positive Correlation in Lower Extremity Deep Venous Thrombosis Chan, K. T., Sze, D. Y., Kuo, W. T., Kothary, N., Louie, J. D., Hovsepian, D. M., Hwang, G. L., Hofmann, L. V. 2009: S89
  • Impact of C-Arm CT in Patients with Hepatocellular Carcinoma Undergoing Transhepatic Arterial Chemoembolization Kothary, N., Tognolini, A., Louie, J. D., Hwang, G., Kuo, W. T., Hovsepian, D. M., Hofmann, L., Sze, D. Y. 2009: S73
  • Safety and Efficacy of Percutaneous Fiducial Marker Implantation for Image-Guided Radiotherapy Kothary, N., Louie, J. D., Kuo, W. T., Hovsepian, D., Sze, D. Y., Hofmann, L. V. 2009: S52
  • Impact of C-Arm CT on Treatment Planning in Patients Undergoing Chemembolization for Tumors Located in Segments with Watershed Arterial Supply Kothary, N., Tognolini, A., Louie, J. D., Hwang, G., Kuo, W. T., Hovsepian, D. M., Hofmann, L., Sze, D. Y. 2009: S72-S73
  • Comparison of Outcomes between TIPS Performed with 8 mm and 10 mm Diameter Stent-Graft Devices Dhanani, R. S., Kothary, N., Hunt, S., Kuo, W. T., Hofmann, L. V., Sze, D. Y. 2008: S78
  • Oral Contraceptive-Induced Deep Venous Thrombosis: A Correlation with May-Thurner Syndrome The, G. A., Rosenberg, J., Kuo, W. T., Kothary, N., Sze, D. Y., Hofmann, L. V. 2008: S26
  • Catheter-directed embolectomy, fragmentation,and thrombolysis for the treatment of massive pulmonary embolim after failure of systemic thrombolysis Kuo, W. T., van den Bosch, M. A., Hofmann, L. V., Louie, J. D., Kothary, N., Sze, D. Y. AMER COLL CHEST PHYSICIANS. 2007: 663S-663S

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