Dr. William T. Kuo is an award-winning physician, clinical researcher, innovator, educator, and patient advocate. He was born in St. Louis, MO and attended high school in Southeast Missouri where he graduated valedictorian. He attended college at Duke University where he received a BS degree with honors. He earned an MD degree from Wake Forest University School of Medicine with distinction in radiology, winning the Meschan Award for radiology excellence. His surgical internship was accomplished at Virginia Mason Medical Center in Seattle, WA. He then trained in a combined Interventional & Diagnostic Radiology Residency program at the University of Rochester Medical Center where he served as Chief Resident, and he was among the first in the nation to complete the Clinical Pathway in Interventional Radiology – ABR prototype for the current Integrated IR-DR Residency. Following this, Dr. Kuo completed Interventional Radiology Fellowship at Stanford University Medical Center. After fellowship, Dr. Kuo was recruited to become faculty in the Stanford Division of Vascular and Interventional Radiology where he was appointed Assistant Professor in 2006, promoted to Associate Professor in 2013, and promoted to Professor of Radiology – Interventional Radiology in 2017.

Dr. Kuo is a recognized expert on advanced IVC filter retrieval, venous interventions, thrombolysis, and catheter-directed therapy (CDT) for acute pulmonary embolism (PE). He has written many seminal and award-winning papers, and his work has been cited in all major guidelines on antithrombotic therapy for venous thromboembolism. In 2009, his PE meta-analysis was the first to reveal the safety and effectiveness of CDT as a life-saving procedure for acute massive PE, leading to major changes in treatment guidelines. Dr. Kuo’s landmark meta-analysis eventually led to wide adoption of catheter-directed therapy for acute life-threatening PE – the 3rd leading cause of cardiovascular death. His work has also inspired many investigators to pursue research on percutaneous PE interventions; and today, based on these collective efforts, Catheter-Directed Therapy is now recognized around the world as a valid treatment option for patients with life-threatening PE.

At Stanford, Dr. Kuo also pioneered the field of advanced IVC filter retrieval. Among several innovations, Dr. Kuo invented excimer laser-assisted IVC filter retrieval and he was the first to perform this procedure in humans. For this achievement, he received the Gary J. Becker Young Investigator Award in 2011 from the SIR Foundation. He has also developed new protocols and techniques to percutaneously remove over 22 embedded filter types and to address several major complications associated with each type. Dr. Kuo’s innovations have changed the paradigm on managing embedded vena cava filters and related complications, to help manage a rising epidemic of filter-related morbidity in the United States. His techniques have allowed thousands more patients each year, previously diagnosed with an irretrievable filter, to achieve safe and successful filter removal regardless of dwell time.

In 2010, Dr. Kuo established the Stanford IVC Filter Clinic as a quaternary referral center dedicated to treating patients with embedded filters and filter-related complications. His clinic routinely accepts challenging cases from around the country and around the world. Dr. Kuo has successfully treated thousands of filter patients referred from all 50 states and from over 10 countries. He is frequently invited to lecture around the country and abroad, and he has testified as an expert before the FDA. His innovative work has been featured on multiple media outlets including the Australian media, Canadian CTV network, ABC News, and NBC Nightly News with Lester Holt. He was also featured in the Netflix Original Documentary – The Bleeding Edge.

He and his wife Rachel have 2 children and live near the Stanford campus.

Clinical Focus

  • Advanced Vena Cava Filter Retrieval
  • Catheter-Directed Thrombolysis
  • Acute Massive and Submassive PE
  • Acute and Chronic DVT
  • Endovascular Treatment of Chronic Total Occlusions
  • Interventional Radiology and Diagnostic Radiology

Academic Appointments

Administrative Appointments

  • Interim Chief of Vascular & Interventional Radiology, Department of Radiology - Stanford Healthcare (June-Sept) (2020 - 2020)
  • Interim Chief of Vascular & Interventional Radiology, Department of Radiology - Stanford University Medical Center (June-Sept) (2017 - 2017)
  • Director-Interventional Radiology Fellowship Program, Department of Radiology - Stanford University Medical Center (2008 - 2020)
  • Director-Interventional Radiology Residency Program, Department of Radiology - Stanford University Medical Center (2016 - Present)
  • Founder & Director-Stanford IVC Filter Clinic, Division of Vascular & Interventional Radiology - Stanford University Medical Center (2010 - Present)

Honors & Awards

  • America's Top Doctors, Castle Connolly Medical Ltd. (2013-2020)
  • Best Doctors in America, Best Doctors Polling & Research (2017, 2018, 2019, 2020)
  • Compassionate Doctor Award, (2012-2020)
  • On-Time Physician Award, (2014, 2016, 2017, 2018, 2019, 2020)
  • Patients' Choice Award, (2012-2020)
  • America’s Most Honored Professionals, The American Registry (2016-2019)
  • Featured Manuscript, Journal of Vascular and Interventional Radiology (2018)
  • Resident/Fellow Research Award - Mentor to Alexander Sheu, SIR Foundation (2017)
  • Resident/Fellow Research Award - Mentor to Andrew Kesselman, SIR Foundation (2017)
  • Best Papers Selection, American Venous Forum (2016)
  • Letter of Commendation-Integrated IR-DR Residency Program, ACGME (2016)
  • Distinguished Abstract, Society of Interventional Radiology (2015)
  • Editors' Choice Article, Journal of Vascular and Interventional Radiology (2015)
  • Elected to Fellowship, Society for Vascular Medicine (2015)
  • Elected to Fellowship, Cardiovascular and Interventional Radiological Society of Europe (2014)
  • Featured Paper, Cardiovascular and Interventional Radiological Society of Europe (2014)
  • Featured Manuscript, Journal of Vascular and Interventional Radiology (2013)
  • Top 10 Doctor Award, (2012, 2013, 2014, 2015)
  • Letter of Commendation-Interventional Radiology Fellowship Program, ACGME (2012)
  • Dr. Gary J. Becker Young Investigator Award, Society of Interventional Radiology Foundation (2011)
  • Elected to Fellowship, Society of Interventional Radiology (2011)
  • Featured Manuscript, Journal of Vascular and 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)
  • Elected To Fellowship, American College of Chest Physicians (2008)
  • Featured Manuscript-ACR/Reuters National Press Release, American College of Radiology (2008)
  • Distinguished Reviewer Award, Journal of Vascular and Interventional Radiology (2007)
  • Top 5 Best Poster Award, American College of Chest Physicians (2007)
  • Chief Resident in Radiology, University of Rochester Medical Center (2003-2005)
  • 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

  • Board Certification: American Board of Radiology, Interventional Radiology and Diagnostic Radiology (2017)
  • 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)

Research & Scholarship

Current Research and Scholarly Interests


Clinical Trials

  • Filter Initial & Long Term Evaluation After Placement and Retrieval Registry Recruiting

    A prospective 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.

    View full details

  • 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)

    View full details

  • 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.

    View full details

  • Clinical Management With SPM System and Validation of the SPM 5 Hour Cutoff in Patients With Symptoms of Gastroparesis Not Recruiting

    This protocol is designed to validate use of the SPM for diagnosis of delayed gastric emptying in patients with symptoms of gastroparesis and assess impact of a SmartPill study on patient management in the gastroparetic populations. Patients with symptoms of gastroparesis will be recruited. Patients will undergo concurrent gastric scintigraphy and SPM testing to determine the presence or absence of delayed gastric emptying based on predetermined diagnostic cutoffs for each technique.

    Stanford is currently not accepting patients for this trial. For more information, please contact Emerald Poon Adler, (650) 721 - 2665.

    View full details

  • ExAblate (MRgFUS) 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.

    View full details

  • HepaSphere/Quadrasphere Microspheres for Delivery of Doxorubicin for the Treatment of Hepatocellular Cancer Not 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.

    Stanford is currently not accepting patients for this trial. For more information, please contact Risa Jiron, 650-736-1598.

    View full details

  • 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.

    View full details

  • 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 C-arm CT supplemented by DSA or DSA only (only DSA images will be used for navigation and tumor vessel tracking). 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.

    View full details

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

    PURPOSE OF RESEARCH: Endovascular stent-graft repair of aortic pathologies is a minimally-invasive alternative to open surgery that may decrease morbidity and mortality, particularly in high risk patients. Optimal patient selection, based on pathology and anatomy, is being defined. Technically successful implantation requires adequate assessment of pathology and anatomy, and development and execution of novel and delicate procedures that resolve the pathology while minimizing morbidity and mortality.

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

    View full details


2020-21 Courses


All Publications

  • Single-Session Pharmacomechanical Catheter-Directed Thrombolysis Using the JETi Thrombectomy Device for Acute Iliofemoral Deep Vein Thrombosis Refractory to Therapeutic Anticoagulation. Journal of vascular and interventional radiology : JVIR Rohr, A. M., Kuo, W. T. 2019

    View details for DOI 10.1016/j.jvir.2019.04.042

    View details for PubMedID 31409567

  • Developing and Evaluating a Simulator for Complex IVC Filter Retrieval. Academic radiology Hoang, N. S., Ge, B. H., Kuo, W. T. 2019


    Simulation models allow trainees to acquire and develop procedural skills without compromising patient safety. Complex inferior vena cava (IVC) filter retrieval requires the operator to be proficient at using devices, such as endobronchial forceps, and advanced techniques to carefully dissect free embedded filter tips encased in fibrous tissue adherent to the IVC. Therefore, it is important to develop an effective, inexpensive model to simulate tip-embedded IVC filter retrieval.Silicone tubes (Flexi-Seal SIGNAL, ConvaTec Inc., Skilman, NJ), IVC filters (Cook Günther Tulip Vena Cava Filter, Cook Medical, Bloomington, IN), and endobronchial forceps (Lymol Medical, Woburn, MA) were obtained to assemble the model. A total of 12 combinations of adhesive binding methods were used to adhere IVC filter fragments to the silicone tubes, and these were blind tested. A single operator with over 10 years of experience using forceps scored the adhesives subjectively on a three-point scale for adherence, elasticity, and tactile feel. The adhesive most similar to IVC fibrous tissue was selected to assemble the final tip-embedded IVC filter model. 20 trainees were then assigned to practice on the model. A 3-point scale scoring metric objectively measured confidence before and after training on the model.Sil-poxy Silicone Adhesive (Smooth-On, Macungie, PA) was found to be the most similar to human IVC fibrous tissue with an average score of 3 of 3 on all metrics. Comparing scores from before and after use of the model, trainee confidence improved significantly (p < 0.1) in all three categories from 1.20 to 2.10 (handling forceps), 1.05 to 2.15 (understanding tactile feel of fibrous tissue), and 1.05 to 1.70 (overall confidence).The development of a low-cost simulator for embedded IVC filters is feasible and can be used to improve trainee confidence and skill for complex IVC filter retrieval.

    View details for DOI 10.1016/j.acra.2019.08.008

    View details for PubMedID 31548112

  • Percutaneous Pulmonary Embolism Thrombectomy and Thrombolysis: Technical Tips and Tricks. Seminars in interventional radiology Devcic, Z., Kuo, W. T. 2018; 35 (2): 129–35


    Catheter-directed therapy (CDT) is now acknowledged as a treatment option for select patients with acute massive or submassive pulmonary embolism (PE), and more patients are being considered for CDT if there is available expertise. Therefore, interventionalists should be aware of the variety of catheter-based treatment options, specific pitfalls to avoid during therapy, and the appropriate treatment endpoints. This article reviews currently available techniques and protocols for treating acute massive and submassive PE, with tips to safely and successfully perform percutaneous PE interventions.

    View details for PubMedID 29872249

  • Endovascular Removal of Fractured Inferior Vena Cava Filter Fragments: 5-Year Registry Data with Prospective Outcomes on Retained Fragments JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kesselman, A. J., Hoang, N., Sheu, A. Y., Kuo, W. T. 2018; 29 (6): 758–64
  • Endovascular Removal of Fractured Inferior Vena Cava Filter Fragments: 5-Year Registry Data with Prospective Outcomes on Retained Fragments. Journal of vascular and interventional radiology : JVIR Kesselman, A. J., Hoang, N. S., Sheu, A. Y., Kuo, W. T. 2018; 29 (6): 758–64


    To evaluate the safety and efficacy of attempted percutaneous filter fragment removal during retrieval of fractured inferior vena cava (IVC) filters and to report outcomes associated with retained filter fragments.Over a 5-year period, 82 consecutive patients presenting with a fractured IVC filter were prospectively enrolled into an institutional review board-approved registry. There were 27 men and 55 women (mean, 47 y; range, 19-85 y). After main filter removal, percutaneous removal of fragments was attempted if they were deemed intravascular and accessible on preprocedural computed tomography (CT), cone-beam CT, and/or intravascular ultrasound; distal pulmonary artery (PA) fragments were left alone. A total of 185 fragments were identified (81 IVC, 33 PA, 16 cardiac, 2 hepatic vein, 1 renal vein, 1 aorta, 51 retroperitoneal). Mean filter dwell time was 2,183 days (range, 59-9,936 d). Eighty-seven of 185 fragments (47%) were deemed amenable to attempted removal: 65 IVC, 11 PA, 8 cardiac, 2 hepatic, and 1 aortic. Primary safety outcomes were major procedure-related complications.Fragment removal was successful in 78 of 87 cases (89.7%; 95% confidence interval [CI], 81.3-95.2). There were 6 minor complications with no consequence (6.9%; 95% CI, 2.6-14.4) involving intraprocedural fragment embolization and 1 major complication (1.1%; 95% CI, 0.0-6.2), a cardiac tamponade that was successfully treated. The complication rate from attempted cardiac fragment removal was 12.5% (1 of 8; 95% CI, 0.3-52.7). Among patients with retained cardiopulmonary fragments (n = 19), 81% remained asymptomatic during long-term clinical follow-up of 845 days (range, 386-2,071 d).Percutaneous removal of filter fragments from the IVC and proximal PAs is safe and effective overall, but attempted intracardiac fragment removal carries a higher risk of complication. Most residual filter fragments not amenable to percutaneous removal remain asymptomatic and may be monitored clinically.

    View details for PubMedID 29706344

  • Prophylactic IVC filter placement in bariatric surgery patients: results from a prospective filter registry. CVIR endovascular Sheu, A. Y., Hoang, N. S., Kesselman, A. J., Liang, T., Rosenberg, J. K., Kuo, W. T. 2018; 1 (1): 13


    Background: Bariatric surgery patients are at increased risk for VTE, but potential risks versus benefits of IVC filters in this group remain unclear. Indwelling filters may increase risk of VTE, and removal of filters in obese patients can be challenging. This study evaluated the incidence of VTE in select bariatric patients receiving prophylactic IVC filters, their risk of filter-related complications, and outcomes from attempted filter retrieval.Results: Postsurgical DVT occurred in 3 patients within 3months postoperatively (3%)(95%CI:1-9%), and 1 patient(1%)(95%CI:0-5%) developed acute low-risk PE at 31days postoperatively, prior to filter removal. All VTE patients were successfully managed with therapeutic anticoagulation alone except one who required thrombolysis. Median filter dwell time was 54days (range:22-1548), and there were no major filter-related complications (0%)(95%CI:0-3%). Retrieval was attempted in 104 cases (97%)(95%CI:92-99%) and successful in 104 cases (100%)(95%CI:97-100%). Thirty-three patients (32%)(95%CI:23-42%) required advanced techniques for filter removal, and there were no major procedural complications (0%)(95%CI:0-3%). Median follow-up occurred at 344days (range:3-1570) days after filter retrieval.Conclusions: No cases of life-threatening post-op PE occurred in this cohort of high-risk bariatric surgery patients receiving prophylactic IVC filters in combination with mechanical and chemoprophylaxis. The risk of filter-related complications was low and retrieval success was high with adjunctive use of advanced techniques.Clinical trial registration: NCT01158482.

    View details for PubMedID 30652145

  • Society of Interventional Radiology Position Statement on Catheter-Directed Therapy for Acute Pulmonary Embolism. Journal of vascular and interventional radiology : JVIR Kuo, W. T., Sista, A. K., Faintuch, S., Dariushnia, S. R., Baerlocher, M. O., Lookstein, R. A., Haskal, Z. J., Nikolic, B., Gemmete, J. J. 2018; 29 (3): 293–97

    View details for PubMedID 29422427

  • Catheter-Directed Therapy for Acute Submassive Pulmonary Embolism: Summary of Current Evidence and Protocols TECHNIQUES IN VASCULAR AND INTERVENTIONAL RADIOLOGY Kesselman, A., Kuo, W. T. 2017; 20 (3): 193–96


    Treatment of acute submassive pulmonary embolism (PE) with thrombolytic therapy remains an area of controversy. For patients who fail or who have contraindications to systemic thrombolysis, catheter-directed therapy (CDT) may be offered depending on the patient's condition and the available institutional resources to perform CDT. Although various CDT techniques and protocols exist, the most studied method is low-dose catheter-directed thrombolytic infusion without mechanical thrombectomy. This article reviews current protocols and data on the use of CDT for acute submassive pulmonary embolism.

    View details for PubMedID 29029714

  • Interventional radiology treatment for pulmonary embolism WORLD JOURNAL OF RADIOLOGY De Gregorio, M. A., Guirola, J. A., Lahuerta, C., Serrano, C., Figueredo, A. L., Kuo, W. T. 2017; 9 (7): 295–303


    Venous thromboembolism (VTE) is an illness that has a potentially life-threatening condition that affects a large percentage of the global population. VTE with pulmonary embolism (PE) is the third leading cause of death after myocardial infarction and stroke. In the first three months after an acute PE, there is an estimated 15% mortality among submassive PE, and 68% mortality in massive PE. Current guidelines suggest fibrinolytic therapy regarding the clinical severity, however some studies suggest a more aggressive treatment approach. This review will summarize the available endovascular treatments and the different techniques with its indications and outcomes.

    View details for DOI 10.4329/wjr.v9.i7.295

    View details for Web of Science ID 000406432400001

    View details for PubMedID 28794825

    View details for PubMedCentralID PMC5529318

  • Laser-Assisted Removal of Embedded Vena Cava Filters A 5-Year First-in-Human Study CHEST Kuo, W. T., Odegaard, J. I., Rosenberg, J. K., Hofmann, L. V. 2017; 151 (2): 417-424


    Many patients are subjected to the potential risks and morbidity associated with an indwelling IVC filter when standard methods fail to remove the filter. We evaluated the safety and effectiveness of the excimer laser-sheath technique for removing embedded IVC filters.Over a 5-year period, 251 consecutive patients undergoing laser-assisted filter retrieval were prospectively enrolled. There were 103 men and 148 women (mean:46 years, range:15-82). Indications for retrieval included symptomatic acute IVC thrombosis, chronic IVC occlusion, and/or pain from filter penetration. Retrieval was also performed to prevent risks from prolonged implantation and potentially to eliminate the need for lifelong anticoagulation. After retrieval failed using 3 times the standard retrieval force (digitally-measured), treatment escalation was attempted using a laser sheath powered by a 308 nm XeCl laser. Success was defined as complete filter detachment and removal from the body. Primary safety outcomes were major procedure-related complications.Laser-assisted retrieval was successful in 249/251(99.2%)(95%CI:97.2-99.9%) with mean implantation of 979 days, range:37-7098 days(>19 years), among retrievable-type filters(n=211) and permanent-type filters(n=40). Average force during failed attempts without laser was 6.7 lbs versus 3.8 lbs during laser-assisted retrievals(p < 0.0001). The major complication rate was 1.6%(95%CI:0.4%-4.0%), and all were successfully treated. Successful retrieval allowed cessation of anticoagulation in 45/46(98%)(95%CI:88%-99%) and alleviated filter-related morbidity in 55/57 patients (96%)(95%CI:88%-99%).The excimer laser-sheath technique is safe and effective for removing embedded IVC filters refractory to standard retrieval and high force. This technique can be used to alleviate or prevent filter-related morbidity and may allow cessation of filter-related anticoagulation.

    View details for DOI 10.1016/j.chest.2016.09.029

    View details for Web of Science ID 000397155000030

  • Stratification, Imaging, and Management of Acute Massive and Submassive Pulmonary Embolism. Radiology Sista, A. K., Kuo, W. T., Schiebler, M., Madoff, D. C. 2017; 284 (1): 5–24


    While pulmonary embolism (PE) causes approximately 100 000-180 000 deaths per year in the United States, mortality is restricted to patients who have massive or submassive PEs. This state of the art review familiarizes the reader with these categories of PE. The review discusses the following topics: pathophysiology, clinical presentation, rationale for stratification, imaging, massive PE management and outcomes, submassive PE management and outcomes, and future directions. It summarizes the most up-to-date literature on imaging, systemic thrombolysis, surgical embolectomy, and catheter-directed therapy for submassive and massive PE and gives representative examples that reflect modern practice. (©) RSNA, 2017.

    View details for DOI 10.1148/radiol.2017151978

    View details for PubMedID 28628412

  • Catheter-directed therapy as a first-line treatment strategy in hemodynamically unstable patients with acute pulmonary embolism: Yes or no? INTERNATIONAL JOURNAL OF CARDIOLOGY Zuin, M., Kuo, W. T., Rigatelli, G., Daggubati, R., Vassiliev, D., Roncon, L. 2016; 225: 14–15

    View details for PubMedID 27694031

  • Inferior Vena Cava Filter Elucidation: How to Identify Specific Inferior Vena Cava Filter Types on Multi-Detector-Row Computed Tomography Imaging JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY Deso, S. E., Kuo, W. T. 2016; 40 (4): 596-602


    The use of inferior vena cava (IVC) filters in the United States has increased substantially over the last 3 decades. In addition, the number of Food and Drug Administration-approved devices has also increased during this time, and there are now more than 24 different IVC filter types that may be encountered in clinical practice. These devices vary substantially with regard to design, retrievability, and risk of potential complications that include fracture, penetration, embolization, migration, recurrent venous thromboembolism, and chronic IVC occlusion. A myriad of devices are now routinely encountered on multi-detector-row computed tomography imaging, but it can be challenging to properly identify a specific IVC filter type. Proper device identification has important clinical consequences because each filter type has associated risks that may otherwise be overlooked. Identifying the specific filter type may allow further radiographic surveillance for known device-specific complications and may identify patients who can benefit from further medical treatment or prompt filter retrieval. Therefore, our purpose was to present a practical method to identify the various IVC filter types that may be encountered on multi-detector-row computed tomography imaging.

    View details for DOI 10.1097/RCT.0000000000000402

    View details for PubMedID 27023853

  • Creation of an iOS and Android Mobile Application for Inferior Vena Cava (IVC) Filters: A Powerful Tool to Optimize Care of Patients with IVC Filters SEMINARS IN INTERVENTIONAL RADIOLOGY Deso, S. E., Idakoji, I. A., Muelly, M. C., Kuo, W. T. 2016; 33 (2): 137-143


    Owing to a myriad of inferior vena cava (IVC) filter types and their potential complications, rapid and correct identification may be challenging when encountered on routine imaging. The authors aimed to develop an interactive mobile application that allows recognition of all IVC filters and related complications, to optimize the care of patients with indwelling IVC filters. The FDA Premarket Notification Database was queried from 1980 to 2014 to identify all IVC filter types in the United States. An electronic search was then performed on MEDLINE and the FDA MAUDE database to identify all reported complications associated with each device. High-resolution photos were taken of each filter type and corresponding computed tomographic and fluoroscopic images were obtained from an institutional review board-approved IVC filter registry. A wireframe and storyboard were created, and software was developed using HTML5/CSS compliant code. The software was deployed using PhoneGap (Adobe, San Jose, CA), and the prototype was tested and refined. Twenty-three IVC filter types were identified for inclusion. Safety data from FDA MAUDE and 72 relevant peer-reviewed studies were acquired, and complication rates for each filter type were highlighted in the application. Digital photos, fluoroscopic images, and CT DICOM files were seamlessly incorporated. All data were succinctly organized electronically, and the software was successfully deployed into Android (Google, Mountain View, CA) and iOS (Apple, Cupertino, CA) platforms. A powerful electronic mobile application was successfully created to allow rapid identification of all IVC filter types and related complications. This application may be used to optimize the care of patients with IVC filters.

    View details for DOI 10.1055/s-0036-1583206

    View details for PubMedID 27247483

  • Evidence-Based Evaluation of Inferior Vena Cava Filter Complications Based on Filter Type SEMINARS IN INTERVENTIONAL RADIOLOGY Deso, S. E., Idakoji, I. A., Kuo, W. T. 2016; 33 (2): 93-100


    Many inferior vena cava (IVC) filter types, along with their specific risks and complications, are not recognized. The purpose of this study was to evaluate the various FDA-approved IVC filter types to determine device-specific risks, as a way to help identify patients who may benefit from ongoing follow-up versus prompt filter retrieval. An evidence-based electronic search (FDA Premarket Notification, MEDLINE, FDA MAUDE) was performed to identify all IVC filter types and device-specific complications from 1980 to 2014. Twenty-three IVC filter types (14 retrievable, 9 permanent) were identified. The devices were categorized as follows: conical (n = 14), conical with umbrella (n = 1), conical with cylindrical element (n = 2), biconical with cylindrical element (n = 2), helical (n = 1), spiral (n = 1), and complex (n = 1). Purely conical filters were associated with the highest reported risks of penetration (90-100%). Filters with cylindrical or umbrella elements were associated with the highest reported risk of IVC thrombosis (30-50%). Conical Bard filters were associated with the highest reported risks of fracture (40%). The various FDA-approved IVC filter types were evaluated for device-specific complications based on best current evidence. This information can be used to guide and optimize clinical management in patients with indwelling IVC filters.

    View details for DOI 10.1055/s-0036-1583208

    View details for PubMedID 27247477

  • Laser-Assisted Venous Thrombectomy for Treatment of Recurrent In-Stent Restenosis and Superior Vena Cava Syndrome. Journal of vascular and interventional radiology : JVIR Ahmed, O., Kuo, W. T. 2016; 27 (4): 603–6

    View details for DOI 10.1016/j.jvir.2015.12.015

    View details for PubMedID 27013007

  • Respiratory-Induced Haemodynamic Changes: A Contributing Factor to IVC Filter Penetration. Cardiovascular and interventional radiology Laborda, A., Kuo, W. T., Ioakeim, I., de Blas, I., Malvè, M., Lahuerta, C., de Gregorio, M. A. 2015; 38 (5): 1192-1197


    The purpose of the study is to evaluate the influence of respiratory-induced vena caval hemodynamic changes on filter migration/penetration.After placement of either a Gunther Tulip or Celect IVC filter, 101 consecutive patients scheduled for filter retrieval were prospectively enrolled in this study. Pre-retrieval CT scans were used to assess filter complications and to calculate cross-sectional area in three locations: at level of filter strut fixation, 3 cm above and 3 cm below. A 3D finite element simulation was constructed on these data and direct IVC pressure was recorded during filter retrieval. Cross-sectional areas and pressures of the vena cava were measured during neutral breathing and in Valsalva maneuver and identified filter complications were recorded. A statistical analysis of these variables was then performed.During Valsalva maneuvers, a 60 % decrease of the IVC cross-sectional area and a fivefold increase in the IVC pressure were identified (p < 0.001). There was a statistically significant difference in the reduction of the cross-sectional area at the filter strut level (p < 0.001) in patient with filter penetration. Difficulty in filter retrieval was higher in penetrated or tilted filters (p < 0.001; p = 0.005). 3D computational models showed significant IVC deformation around the filter during Valsalva maneuver.Caval morphology and hemodynamics are clearly affected by Valsalva maneuvers. A physiological reduction of IVC cross-sectional area is associated with higher risk of filter penetration, despite short dwell times. Physiologic data should be used to improve future filter designs to remain safely implanted over longer dwell times.

    View details for DOI 10.1007/s00270-015-1077-4

    View details for PubMedID 25795475

  • Pulmonary Embolism Response to Fragmentation, Embolectomy, and Catheter Thrombolysis (PERFECT) Initial Results From a Prospective Multicenter Registry CHEST Kuo, W. T., Banerjee, A., Kim, P. S., DeMarco, F. J., Levy, J. R., Facchini, F. R., Unver, K., Bertini, M. J., Sista, A. K., Hall, M. J., Rosenberg, J. K., de Gregorio, M. A. 2015; 148 (3): 667-673


    Systemic thrombolysis for acute PE carries up to a 20% risk of major bleeding, including a 2-5% risk of hemorrhagic stroke. We evaluated the safety and effectiveness of catheter-directed therapy (CDT) as an alternative treatment for acute PE.One hundred one consecutive patients receiving CDT for acute PE were prospectively enrolled in a multicenter registry. Massive PE (n=28) and submassive PE (n=73) were treated with immediate catheter-directed mechanical or pharmacomechanical thrombectomy and/or catheter-directed thrombolysis via low-dose hourly drug infusion with tPA or urokinase. Clinical success was defined as meeting all criteria: stabilization of hemodynamics, improvement in pulmonary hypertension and/or right heart strain, and survival to hospital discharge. Primary safety outcomes were major procedure-related complications and major bleeding events.There were 53 men and 48 women with average age of 60 years (range, 22-86 years) and mean BMI of 31.03±7.20 kg/m2. The average thrombolytic doses were 28.0±11 mg tPA (n=76) and 2,697,101±936,287 IU for urokinase (n=23). Clinical success was achieved in 24/28 (85.7%)(95% CI, 67.3%-96.0%) patients with massive PE and 71/73 (97.3%)(95% CI, 90.5%-99.7%) with submassive PE. The mean PA pressure improved from 51.17±14.06 mmHg to 37.23±15.81 mmHg (n=92)(P<0.0001). Among patients monitored with follow-up echocardiography, 57/64 (89.1%)(95% CI, 78.8%-95.5%)(p<0.0001) showed improvement in right heart strain. There were no major procedure-related complications, no major hemorrhages, and no hemorrhagic strokes.Catheter-directed therapy improves clinical outcomes in acute PE patients while minimizing the risk of major bleeding. At experienced centers, CDT is a safe and effective treatment for both acute massive and submassive PE.NCT01097928, available at

    View details for DOI 10.1378/chest.15-0119

    View details for PubMedID 25856269

  • Bard denali inferior vena cava filter fracture and embolization resulting in cardiac tamponade: a device failure analysis. Journal of vascular and interventional radiology Kuo, W. T., Robertson, S. W. 2015; 26 (1): 111-115 e1


    A 46-year-old woman underwent inferior vena cava filter placement before bariatric surgery and returned within 6 months for routine removal. She complained of a 1-week history of severe chest pain, and during retrieval, two fractured filter components were identified including one arm in the right ventricle. The filter body and one fragment were successfully retrieved, but the fragment in the right ventricle was refractory to percutaneous retrieval. During open-heart surgery, the fragment was found traversing through the ventricular wall resulting in cardiac tamponade. Electron microscopic fragment analysis revealed high-cycle metal fatigue indicating the filter design failed to withstand this patient's natural inferior vena cava biomechanical motions.

    View details for DOI 10.1016/j.jvir.2014.08.001

    View details for PubMedID 25541449

  • 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


    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


    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. 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


    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 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


    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 PubMedID 21562933

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


    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 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


    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 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


    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 PubMedID 21050774

  • 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
  • Optimizing endovascular therapy for acute PE: primum non nocere. J Vasc Interv Radiol Kuo WT, Hofmann LV 2010; 21 (11): 1776-1777
  • 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


    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 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


    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 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


    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 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


    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 PubMedID 17142717

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


    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


    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

  • Spanish multicenter real - life registry of retrievable vena cava filters (REFiVeC). CVIR endovascular De Gregorio, M. A., Guirola, J. A., Urbano, J., Diaz-Lorenzo, I., Munoz, J. J., Villacastin, E., Lopez-Medina, A., Figueredo, A. L., Guerrero, J., Sierre, S., Blazquez Sanchez, J., Kuo, W. T., Jimenez, D. 2020; 3 (1): 26


    BACKGROUND: The treatment of venous thromboembolic disease the treatment of choice is systemic anticoagulation. However, the interruption of the inferior vena cava with filters has been recommended when anticoagulation fails or there is a contraindication. Due to the rising inferior vena cava filter (IVCF) complications, physicians are encouraged to retrieve them when there is no longer recommended. In daily practice, it may be a difficult close follow-up of these patients. In this study, the primary objective was to evaluate the IVCF retrieval rate of all implanted filters in a Spanish registry. Secondary objectives were to analyze the causes of failed retrieval, procedure-related complications, and outcomes at a 12-month follow-up.RESULTS: Three hundred fifty-six vena cava filters were implanted in 355 patients. The types of filter were: Gunther Tulip (Cook Medical) 160 (44.9%), Optease (Cordis) 77 (21.6%), Celect (Cook Medical) 49 (13, 7%), Aegisy (Lifetech Scientific) 33 (9.2%), Option ELITE (Argon Medical devices) 16 (4.4%), Denali filter (BD Bard) 11 (3.08%), ALN filter (ALN) 10 (2.8%). Removal was achieved in 274/356 (76,9%). eighty-two (23,1%) IVCF were not retrieved due to the following: 41 (11,5%) patients required ongoing filtration, 24 IVCF (6,7%) patients died before retrieval, and 17 (4,7%) impossibility of retrieval because of a tilted and embedded filter apex. There were no major complications observed.CONCLUSIONS: The global retrieval rate of IVCF was achieved in 76.9%, and the adjusted retrieval rate was of 94.15% with no major complications. IVCF tilting was associated with failure of filter removal in less than 5% of cases. This study demonstrates that the retrieval procedure of IVCF is controlled by the clinician and not by the interventional radiologist.

    View details for DOI 10.1186/s42155-020-00114-5

    View details for PubMedID 32419040

  • Diagnostic performance of lower extremity Doppler ultrasound in detecting iliocaval obstruction. Journal of vascular surgery. Venous and lymphatic disorders Hui, J. Z., Goldman, R. E., Mabud, T. S., Arendt, V. A., Kuo, W. T., Hofmann, L. V. 2020


    To retrospectively evaluate the performance of two commonly used Doppler ultrasound parameters, namely, venous flow phasicity and response to Valsalva maneuver, in detecting iliocaval obstruction.All imaging studies of patients seen by interventional radiology for lower extremity venous disease at a single institution from 1996 to 2018 were retrospectively identified. Lower extremity ultrasounds with a concurrent magnetic resonance, computed tomography, or conventional venogram performed within the next 7 days, which served as gold standard, were further identified (n = 192 examinations, including 313 limbs). Iliocaval obstruction were assessed by two ultrasound criteria: (1) nonphasic flow and/or (2) nonresponsive flow to Valsalva in the common femoral vein. The sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) for diagnosing iliocaval obstruction were calculated for each ultrasound criterion, and also for when the two criteria were assessed jointly.Of the 313 limbs assessed for venous flow phasicity, 133 (42.5%) had an iliocaval obstruction confirmed on subsequent venography. Nonphasic flow demonstrated a sensitivity of 69.2%, specificity of 82.8%, NPV of 78.4%, and PPV of 74.8% for diagnosing iliocaval obstruction. Of the 212 limbs assessed for Valsalva response, 88 (41.5%) had a confirmed iliocaval obstruction. Nonresponsive flow to Valsalva demonstrated a sensitivity of 13.6%, specificity of 97.6%, NPV of 61.6%, and PPV of 80.0% for diagnosing iliocaval obstruction. Joint assessment using phasicity and Valsalva criteria demonstrated a sensitivity of 68.2%, specificity of 87.2%, NPV of 79.6%, and PPV of 78.9%.In this tertiary care setting, Doppler ultrasound examination was not a reliable diagnostic tool for detecting iliocaval obstruction.

    View details for DOI 10.1016/j.jvsv.2019.12.074

    View details for PubMedID 32107162

  • Toward Data-Driven Learning Healthcare Systems in Interventional Radiology: Implementation to Evaluate Venous Stent Patency. Journal of digital imaging Cohn, D. M., Mabud, T. S., Arendt, V. A., Souffrant, A. D., Jeon, G. S., An, X., Kuo, W. T., Sze, D. Y., Hofmann, L. V., Rubin, D. L. 2019


    We developed a code and data-driven system (learning healthcare system) for gleaning actionable clinical insight from interventional radiology (IR) data. To this end, we constructed a workflow for the collection, processing and analysis of electronic health record (EHR), imaging, and cancer registry data for a cohort of interventional radiology patients seen in the IR Clinic at our institution over a more than 20-year period. As part of this pipeline, we created a database in REDCap (VITAL) to store raw data, as collected by a team of clinical investigators and the Data Coordinating Center at our university. We developed a single, universal pre-processing codebank for our VITAL data in R; in addition, we also wrote widely extendable and easily modifiable analysis code in R that presents results from summary statistics, statistical tests, visualizations, Kaplan-Meier analyses, and Cox proportional hazard modeling, among other analysis techniques. We present our findings for a test case of supra versus infra-inguinal ligament stenting. The developed pre-processing and analysis pipelines were memory and speed-efficient, with both pipelines running in less than 2min. Three different supra-inguinal ligament veins had a statistically significant improvement in vein diameters post-stenting versus pre-stenting, while no infra-inguinal ligament veins had a statistically significant improvement (due either to an insufficient sample size or a non-significant p value). However, infra-inguinal ligament stenting was not associated with worse restenosis or patency outcomes in either a univariate (summary-statistics and Kaplan-Meier based) or multivariate (Cox proportional hazard model based) analysis.

    View details for DOI 10.1007/s10278-019-00280-6

    View details for PubMedID 31650318

  • Inferior Vena Cava Atresia: Characterisation of Risk Factors, Treatment, and Outcomes. Cardiovascular and interventional radiology Mabud, T. S., Sailer, A. M., Swee, J. K., Tamboli, M., Arendt, V. A., Jeon, G., An, X., Cohn, D. M., Kuo, W. T., Hofmann, L. V. 2019


    PURPOSE: To characterise (1) the risk factors associated with inferior vena cava (IVC) atresia, (2) the radiographic and clinical presentations of deep vein thrombosis (DVT) in patients with IVC atresia, and (3) the treatment and outcome of DVT in patients with IVC atresia.METHODS: The electronic medical record was systematically reviewed for thrombotic risk factors in patients who presented with lower-extremity DVT (n=409) at a single centre between 1996 and 2017. Patients with IVC atresia were identified based on imaging and chart review. Differences in demographics and thrombotic risk factors between patients with and without IVC atresia were statistically assessed. Extent and chronicity of DVT on imaging, clinical presentation, treatment, and outcomes were evaluated for all patients with IVC atresia.RESULTS: 4.2% of DVT patients (17/409) were found to have IVC atresia; mean age at diagnosis was 25.5±9.4years. The rate of heritable thrombophiliawas significantly higher in patients with IVC atresia compared to patients without IVC atresia (52.9% vs. 17.9%, p<0.0001). There were bilateral DVT in 70.6% of IVC atresia patients; DVT was chronic in 41.2% and acute on chronic in 58.8%. Pre-intervention Villalta scores were 13.9±9.8 in the left limb and 8.5±7.0 in the right limb. DVT in IVC atresia patients was typically treated with catheter-directed thrombolysis followed by stent placement, achieving complete or partial symptom resolution in 78.6% of cases.CONCLUSION: Thrombotic risk factors such as heritable thrombophilia are associated with IVC atresia. IVC atresia patients can experience high burdens of lower-extremity thrombotic disease at a young age which benefit from endovascular treatment.LEVEL OF EVIDENCE: Level 4.

    View details for DOI 10.1007/s00270-019-02353-z

    View details for PubMedID 31650242

  • Lower Extremity Venous Stent Placement: A Large Retrospective Single-Center Analysis. Journal of vascular and interventional radiology : JVIR Mabud, T. S., Cohn, D. M., Arendt, V. A., Jeon, G., An, X., Fu, J., Souffrant, A. D., Sailer, A. M., Shah, R., Wang, D., Sze, D. Y., Kuo, W. T., Rubin, D. L., Hofmann, L. V. 2019


    PURPOSE: To study short-term and long-term outcomes of lower extremity venous stents placed at a single center and to characterize changes in vein diameter achieved by stent placement.MATERIALS AND METHODS: A database of all patients who received lower extremity venous stents between 1996 and 2018 revealed 1,094 stents were placed in 406 patients (172 men, 234 women; median age, 49 y) in 513 limbs, including patients with iliocaval stents (9.4% acute thrombosis, 65.3% chronic thrombosis, 25.3% nonthrombotic lesions). Primary, primary assisted, and secondary patency rates were assessed for lower extremity venous stents at 1, 3, and 5 years using Kaplan-Meier analyses and summary statistics. Subset analyses and Cox regression were performed to identify risk factors for patency loss. Vein diameters and Villalta scores before and up to 12 months after stent placement were compared. Complication and mortality rates were calculated.RESULTS: Primary, primary assisted, and secondary patency rates at 5 years were 57.3%, 77.2%, and 80.9% by Kaplan-Meier methods and 78.6%, 90.3%, and 92.8% by summary statistics. Median follow-up was 199 days (interquartile range, 35.2-712.0 d). Patency rates for the subset of patients (n= 46) with ≥ 5 years of follow-up (mean ± SD 9.1 y ± 3.4) were nearly identical to cohort patency rates at 5 years. Patients with inferior vena cava stent placement (hazard ratio 2.11, P < .0001) or acute thrombosis (hazard ratio 3.65, P < .0001) during the index procedure had significantly increased risk of losing primary patency status. Vein diameters were significantly greater after stent placement. There were no instances of stent fracture, migration, or structural deformities. In patients with chronic deep vein thrombosis, Villalta scores significantly decreased after stent placement (from 15.7 to 7.4, P < .0001). Perioperative mortality was < 1%, and major perioperative complication rate was 3.7%.CONCLUSIONS: Cavo-ilio-femoral stent placement for venous occlusive disease achieves improvement of vein disease severity scores, increase in treated vein diameters, and satisfactory long-term patency rates.

    View details for DOI 10.1016/j.jvir.2019.06.011

    View details for PubMedID 31542273

  • Deep-Learning for Automated Classification of Inferior Vena Cava Filter Types on Radiographs. Journal of vascular and interventional radiology : JVIR Ni, J. C., Shpanskaya, K., Han, M., Lee, E. H., Do, B. H., Kuo, W. T., Yeom, K. W., Wang, D. S. 2019


    PURPOSE: To demonstrate the feasibility and evaluate the performance of a deep-learning convolutional neural network (CNN) classification model for automated identification of different types of inferior vena cava (IVC) filters on radiographs.MATERIALS AND METHODS: In total, 1,375 cropped radiographic images of 14 types of IVC filters were collected from patients enrolled in a single-center IVC filter registry, with 139 images withheld as a test set and the remainder used to train and validate the classification model. Image brightness, contrast, intensity, and rotation were varied to augment the training set. A 50-layer ResNet architecture with fixed pre-trained weights was trained using a soft margin loss over 50 epochs. The final model was evaluated on the test set.RESULTS: The CNN classification model achieved a F1 score of 0.97 (0.92-0.99) for the test set overall and of 1.00 for 10 of 14 individual filter types. Of the 139 test set images, 4 (2.9%) were misidentified, all mistaken for other filter types that appear highly similar. Heat maps elucidated salient features for each filter type that the model used for class prediction.CONCLUSIONS: A CNN classification model was successfully developed to identify 14 types of IVC filters on radiographs and demonstrated high performance. Further refinement and testing of the model is necessary before potential real-world application.

    View details for DOI 10.1016/j.jvir.2019.05.026

    View details for PubMedID 31542278

  • Hemopericardium and Cardiac Tamponade as a Complication of Vena Caval Filters: Systematic Review of the Published Literature and the MAUDE Database CLINICAL AND APPLIED THROMBOSIS-HEMOSTASIS Bikdeli, B., Kirtane, A. J., Jimenez, D., Green, P., Spencer, F. A., Kuo, W. T., Krumholz, H. M., Parikh, S. A. 2019; 25
  • Hemopericardium and Cardiac Tamponade as a Complication of Vena Caval Filters: Systematic Review of the Published Literature and the MAUDE Database. Clinical and applied thrombosis/hemostasis : official journal of the International Academy of Clinical and Applied Thrombosis/Hemostasis Bikdeli, B., Kirtane, A. J., Jimenez, D., Green, P., Spencer, F. A., Kuo, W. T., Krumholz, H. M., Parikh, S. A. 2019; 25: 1076029619849111

    View details for PubMedID 31088147

  • Success in Optional Vena Cava Filter Retrieval. An Analysis of 246 Patients. Archivos de bronconeumologia de Gregorio, M. A., Guirola, J. A., Serrano, C., Figueredo, A., Kuo, W. T., Quezada, C. A., Jimenez, D. 2018


    This study assessed vena cava filter (VCF) retrieval rates and factors associated with retrieval failure in a single center cohort.We conducted an observational retrospective cohort study. The primary endpoint was the percentage of patients whose VCF was retrieved. We performed logistic regression to identify variables associated with retrieval failure.During the study period, 246 patients received a VCF and met the eligibility requirements to be included in the study; 151 (61%) patients received a VCF due to contraindication to anticoagulation, 69 (28%) patients had venous thromboembolism (VTE) and a high risk of recurrence, and 26 (11%) patients received a filter due to recurrent VTE while on anticoagulant therapy. Of 236 patients who survived the first month after diagnosis of VTE, VCF was retrieved in 96%. Retrieval rates were significantly lower for patients with recurrent VTE while on anticoagulation, compared with patients with contraindication to anticoagulation or patients with a high risk of recurrence (79% vs. 97% vs. 100%, respectively; P<0.01). Mean time to retrieval attempt was significantly associated with retrieval failure (137.8 ± 65.3 vs. 46.3 ± 123.1 days, P<0.001).In this single center study, VCF retrieval success was 96%. A delay in the attempt to retrieve the VCF correlated significantly with retrieval failure.

    View details for PubMedID 29566970

  • Endovascular Management of May-Thurner Syndrome in Adolescents: A Single-Center Experience JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Goldman, R. E., Arendt, V. A., Kothary, N., Kuo, W. T., Sze, D. Y., Hofmann, L. V., Lungren, M. P. 2017; 28 (1): 71-77


    To report a single-center experience in regard to the technique, safety, and clinical outcomes of endovascular therapy for treatment of May-Thurner syndrome (MTS) in adolescent patients.A retrospective review identified 10 patients (6 female; mean age, 16 y; range, 12-18 y; mean weight, 73 kg; range, 50-116 kg) treated by endovascular therapy for MTS from 1998 to 2015. Clinical presentations consisted of acute thrombotic MTS (n = 6) and nonthrombotic MTS (n = 4). Catheter-directed thrombolysis was performed in all cases of thrombosis. Venoplasty and stent placement were performed in all cases. Self-expanding stents 12-16 mm in diameter and 4-9 cm in length were deployed.No major periprocedural complications were observed. Median follow-up was 32 months (range, 6-109 mo). Primary and secondary patency rates were 79% and 100% at 12 months and 79% and 89% at 36 months, respectively. In a single patient with permanent loss of flow in the treated segment, multiple risk factors for thrombosis were identified. Rates of posttreatment symptoms were 0% by Villalta score and 60% (n = 6; mild symptoms) by modified Villalta score at the last clinical follow-up.Endovascular therapy for the treatment of MTS in our adolescent cohort was safe and effective in relieving venous obstruction. Stent placement in patients with underlying thrombophilic disorders is associated with loss of secondary patency, suggesting the need for further consideration in this population.

    View details for DOI 10.1016/j.jvir.2016.09.005

    View details for Web of Science ID 000392465200010

  • Research Priorities in Submassive Pulmonary Embolism: Proceedings from a Multidisciplinary Research Consensus Panel JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Sista, A. K., Goldhaber, S. Z., Vedantham, S., Kline, J. A., Kuo, W. T., Kahn, S. R., Kabrhel, C., McLaughlin, V. V., White, S. B., Kim, N. H., Gray, M., Simon, M. A., Benenati, J. F., Misra, S., Sterling, K. M., Kee, S. T., Konstantinides, S. V., Jaff, M. R., Kearon, C. 2016; 27 (6): 787-794

    View details for DOI 10.1016/j.jvir.2016.03.035

    View details for PubMedID 27287967

  • Superselective Chemoembolization of HCC: Comparison of Short-term Safety and Efficacy between Drug-eluting LC Beads, QuadraSpheres, and Conventional Ethiodized Oil Emulsion. Radiology Duan, F., Wang, E. Q., Lam, M. G., Abdelmaksoud, M. H., Louie, J. D., Hwang, G. L., Kothary, N., Kuo, W. T., Hofmann, L. V., Sze, D. Y. 2016; 278 (2): 612-621


    Purpose To study the comparative short-term safety and efficacy of transcatheter arterial chemoembolization (TACE) with drug-eluting LC Beads loaded with doxorubicin (DEBDOX), doxorubicin-eluting QuadraSpheres (hqTACE), and conventional TACE using ethiodized oil for superselective C-arm computed tomography (CT)-guided treatment of hepatocellular carcinoma (HCC) after the onset of drug shortages. Materials and Methods From March 2010 to March 2011, 166 patients with HCC were treated with 232 superselective TACE procedures using C-arm cone-beam CT at one institution. Patients underwent treatment depending on the availability of materials after the onset of drug shortages. Conventional TACE with doxorubicin, cisplatin, and Ethiodol was performed for 159 procedures, DEBDOX TACE was performed for 47, and hqTACE was performed for 26. Toxicity and objective response were compared at 3 months after treatment. Data were stratified for the high-risk population (Child-Pugh class B, performance status 1, bilobar disease, and/or post-resection recurrence) and initial versus repeat treatment. Kruskal-Wallis H test, Mann-Whitney U test, and Fisher exact test were used to compare the groups, with Bonferroni correction where needed. Results Whole liver response rates trended higher for conventional TACE (conventional TACE, 65.4%; DEBDOX, 63.8%; hqTACE, 53.8%) (P = .085). Only minor trends for differences in toxicity were observed between the three groups. Low-risk patients had higher whole liver (P = .001) and treated lesion (P = .007) response rates when treated with conventional TACE, but no significant differences were seen for DEBDOX and hqTACE. Treatment-naive patients also had higher whole liver (P = .012) and treated lesion (P = .056) response rates. No advantages for drug-eluting microspheres were found. Conclusion Within statistical power limitations, overall toxicity and efficacy were equivalent in patients treated with LC Beads, QuadraSpheres, or ethiodized oil emulsions, including in high-risk patients, when performed superselectively with cone-beam C-arm CT guidance. (©) RSNA, 2015.

    View details for DOI 10.1148/radiol.2015141417

    View details for PubMedID 26334787

  • Catheter-Directed Interventions for Acute Pulmonary Embolism The Jury Is Still Out Response CHEST Kuo, W. T., De Gregorio, M. A. 2015; 148 (3): E94–E95

    View details for PubMedID 26324146

  • A Prospective, Single-Arm, Multicenter Trial of Ultrasound-Facilitated, Catheter-Directed, Low-Dose Fibrinolysis for Acute Massive and Submassive Pulmonary Embolism The SEATTLE II Study JACC-CARDIOVASCULAR INTERVENTIONS Piazza, G., Hohlfelder, B., Jaff, M. R., Ouriel, K., Engelhardt, T. C., Sterling, K. M., Jones, N. J., Gurley, J. C., Bhatheja, R., Kennedy, R. J., Goswami, N., Natarajan, K., Rundback, J., Sadiq, I. R., Liu, S. K., Bhalla, N., Raja, M. L., Weinstock, B. S., Cynamon, J., Elmasri, F. F., Garcia, M. J., Kumar, M., Ayerdi, J., Soukas, P., Kuo, W., Liu, P., Goldhaber, S. Z. 2015; 8 (10): 1382-1392


    This study conducted a prospective, single-arm, multicenter trial to evaluate the safety and efficacy of ultrasound-facilitated, catheter-directed, low-dose fibrinolysis, using the EkoSonic Endovascular System (EKOS, Bothell, Washington).Systemic fibrinolysis for acute pulmonary embolism (PE) reduces cardiovascular collapse but causes hemorrhagic stroke at a rate exceeding 2%.Eligible patients had a proximal PE and a right ventricular (RV)-to-left ventricular (LV) diameter ratio ≥0.9 on chest computed tomography (CT). We included 150 patients with acute massive (n = 31) or submassive (n = 119) PE. We used 24 mg of tissue-plasminogen activator (t-PA) administered either as 1 mg/h for 24 h with a unilateral catheter or 1 mg/h/catheter for 12 h with bilateral catheters. The primary safety outcome was major bleeding within 72 h of procedure initiation. The primary efficacy outcome was the change in the chest CT-measured RV/LV diameter ratio within 48 h of procedure initiation.Mean RV/LV diameter ratio decreased from baseline to 48 h post-procedure (1.55 vs. 1.13; mean difference, -0.42; p < 0.0001). Mean pulmonary artery systolic pressure (51.4 mm Hg vs. 36.9 mm Hg; p < 0.0001) and modified Miller Index score (22.5 vs. 15.8; p < 0.0001) also decreased post-procedure. One GUSTO (Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries)-defined severe bleed (groin hematoma with transient hypotension) and 16 GUSTO-defined moderate bleeding events occurred in 15 patients (10%). No patient experienced intracranial hemorrhage.Ultrasound-facilitated, catheter-directed, low-dose fibrinolysis decreased RV dilation, reduced pulmonary hypertension, decreased anatomic thrombus burden, and minimized intracranial hemorrhage in patients with acute massive and submassive PE. (A Prospective, Single-arm, Multi-center Trial of EkoSonic® Endovascular System and Activase for Treatment of Acute Pulmonary Embolism (PE) [SEATTLE II]; NCT01513759).

    View details for DOI 10.1016/j.jcin.2015.04.020

    View details for Web of Science ID 000360017500018

  • Optimal imaging surveillance schedules after liver-directed therapy for hepatocellular carcinoma. Journal of vascular and interventional radiology Boas, F. E., Do, B., Louie, J. D., Kothary, N., Hwang, G. L., Kuo, W. T., Hovsepian, D. M., Kantrowitz, M., Sze, D. Y. 2015; 26 (1): 69-73


    To optimize surveillance schedules for the detection of recurrent hepatocellular carcinoma (HCC) after liver-directed therapy.New methods have emerged that allow quantitative analysis and optimization of surveillance schedules for diseases with substantial rates of recurrence such as HCC. These methods were applied to 1,766 consecutive chemoembolization, radioembolization, and radiofrequency ablation procedures performed on 910 patients between 2006 and 2011. Computed tomography or magnetic resonance imaging performed just before repeat therapy was set as the time of "recurrence," which included residual and locally recurrent tumor as well as new liver tumors. Time-to-recurrence distribution was estimated by Kaplan-Meier method. Average diagnostic delay (time between recurrence and detection) was calculated for each proposed surveillance schedule using the time-to-recurrence distribution. An optimized surveillance schedule could then be derived to minimize the average diagnostic delay.Recurrence is 6.5 times more likely in the first year after treatment than in the second. Therefore, screening should be much more frequent in the first year. For eight time points in the first 2 years of follow-up, the optimal schedule is 2, 4, 6, 8, 11, 14, 18, and 24 months. This schedule reduces diagnostic delay compared with published schedules and is cost-effective.The calculated optimal surveillance schedules include shorter-interval follow-up when there is a higher probability of recurrence and longer-interval follow-up when there is a lower probability. Cost can be optimized for a specified acceptable diagnostic delay or diagnostic delay can be optimized within a specified acceptable cost.

    View details for DOI 10.1016/j.jvir.2014.09.013

    View details for PubMedID 25446423

  • Influence of breathing movements and Valsalva maneuver on vena caval dynamics. World journal of radiology Laborda, A., Sierre, S., Malvè, M., de Blas, I., Ioakeim, I., Kuo, W. T., De Gregorio, M. A. 2014; 6 (10): 833-839


    To study changes produced within the inferior vena cava (IVC) during respiratory movements and identify their possible clinical implications.This study included 100 patients (46 women; 54 men) over 18 years of age who required an abdominal computed tomography (CT) and central venous access. IVC cross-sectional areas were measured on CT scans at three levels, suprarenal (SR), juxtarenal (JR) and infrarenal (IR), during neutral breathing and again during the Valsalva maneuver. All patients were instructed on how to perform a correct Valsalva maneuver. In order to reduce the total radiation dose in our patients, low-dose CT protocols were used in all patients. The venous blood pressure (systolic, diastolic and mean) was invasively measured at the same three levels with neutral breathing and the Valsalva maneuver during venous port implantation. From CT scans, three-dimensional models of the IVC were constructed and a collapsibility index was calculated for each patient. These data were then correlated with venous pressures and cross-sectional areas.The mean patient age was 51.64 ± 12.01 years. The areas of the ellipse in neutral breathing were 394.49 ± 85.83 (SR), 380.10 ± 74.55 (JR), and 342.72 ± 49.77 mm(2) (IR), and 87.46 ± 18.35 (SR), 92.64 ± 15.36 (JR) and 70.05 ± 9.64 mm(2) (IR) during the Valsalva (Ps < 0.001). There was a correlation between areas in neutral breathing and in the Valsalva maneuver (P < 0.05 in all areas). Large areas decreased more than smaller areas. The collapsibility indices were 0.49 ± 0.06 (SR), 0.50 ± 0.04 (JR) and 0.50 ± 0.04 (IR), with no significant differences in any region. Reconstructed three-dimensional models showed a flattening of the IVC during Valsalva, adopting an ellipsoid cross-sectional shape. The mean pressures with neutral breathing were 9.44 ± 1.78 (SR), 9.40 ± 1.44 (JR) and 8.84 ± 1.03 mmHg (IR), and 81.08 ± 21.82 (SR), 79.88 ± 19.01 (JR) and 74.04 ± 16.56 mmHg (IR) during Valsalva (Ps < 0.001). There was a negative correlation between cross-sectional caval area and venous blood pressure, but this was not statistically significant in any of the cases. There was a significant correlation between diastolic and mean pressures measured during neutral breathing and in Valsalva.Respiratory movements have a major influence on IVC dynamics. The increase in intracaval pressure during Valsalva results in a significant decrease in the IVC cross-sectional area.

    View details for DOI 10.4329/wjr.v6.i10.833

    View details for PubMedID 25349666

    View details for PubMedCentralID PMC4209428

  • 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
  • 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


    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 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


    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

    View details for DOI 10.1016/S0140-6736(11)61875-8

    View details for PubMedID 22172245

  • 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


    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 PubMedID 22133709

  • 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
  • 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
  • Common iliac vein stenosis: a risk factor for oral contraceptive-induced deep vein thrombosis 36th Annual Scientific Meeting of the Society-of-Interventional-Radiology 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


    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 PubMedID 21893308

  • 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


    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 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


    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 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


    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 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


    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 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


    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 PubMedID 21276911

  • 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
  • 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


    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 PubMedID 20884234

  • 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


    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 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


    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 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


    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

  • 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
  • Transjugular Intrahepatic Portosystemic Shunt Anesthesiologist's Manual of Surgical Procedures Kuo, W. T. Lippincott Williams & Wilkins. 2010
  • 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


    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 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


    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 PubMedID 19019700

  • 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
  • A Novel Rat Hepatocellular Carcinoma Model Designed for In Vivo Evaluation of Image-Guided Therapies van den Bosch, M. A., Higgens, L., Hwang, G., Katzenberg, R. H., Willmann, J. K., Paulmurugan, R., Kuo, W. T., Kothary, N., Sze, D. Y., Gambhir, S. S., Hofmann, L. V. 2008: S136–S137
  • Catheter-Directed Therapy for Massive Pulmonary Embolism: Systematic Review & Meta-Analysis of the Modern Technique Kuo, W. T., van den Bosch, M. A., Sze, D. Y., Gould, M. K., Kothary, N., Hofmann, L. V. 2008: S6
  • In Vitro Transfection of Hepatoma Cells and Hepatocytes with a Nonviral Vector Using Protamine and Ethiodol Higgins, L. J., van den Bosch, M., Hwang, G., Paulmurugan, R., Kothary, N., Kuo, W. T., Sze, D. Y., Katzenberg, R., Gambhir, S. S., Hofmann, L. V. 2008
  • Safety and Efficacy of Ethanolamine for Embolization of Gastric Varices in Patients with Portal Hypertension Kothary, N., Kuo, W. T., Louie, J., Hofmann, L. V., Sze, D. Y. 2008: S74–S75
  • 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 CHEST 2007 Conference 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
  • Retrieval of the Difficult Günther-Tulip IVC Filter: Snare over guide wire loop technique Kuo, W. T., Kee, S. T., Kothary, N., Sze, D. Y., Hofmann, L. V. 2007: S124
  • Comparison of Vasa Vasorum after Intravascular Stent Placement with Sirolimus Coated and Non-Drug Coated Stents Sahler, L. G., Fitzgerald, J. M., Arslan, B., Patel, N. C., Kuo, W. T., Lee, D. E., Sasson, T., Waldman, D. L. 2005: S63
  • 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
  • Superselective Arterial Coil Embolization for the Treatment of Lower Gastrointestinal Hemorrhage Kuo, W. T., Lee, D. E., Saad, W. E., Patel, N., Sahler, L. G., Waldman, D. L. 2003: S13
  • 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


    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

Latest information on COVID-19