Michael D Dake

Stanford University, Palo Alto, California, United States

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Publications (178)738.91 Total impact

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    ABSTRACT: Aneurysms and dissections of the descending thoracic aorta represent a complex substrate with a variety of therapeutic options. The introduction of thoracic endovascular aortic repair (TEVAR) has revolutionized the treatment of thoracic aortic disease. However, longitudinal analyses of post-TEVAR outcomes appropriately stratified by aortic disease remain limited. A total of 11,996 patients undergoing TEVAR from 2005-2010 were identified from the Medicare/Centers for Medicare and Medicaid Services database. Patients were stratified by underlying aortic disease and the presence of Current Procedural Terminology (CPT) codes. Survival was assessed using Kaplan-Meier analysis. Cox proportional hazards analysis determined predictors of survival from TEVAR. After TEVAR, patients had a median survival of 57.6 months (95% confidence interval, 54.9-61.3 months). Although patients without CPT codes had significantly fewer recorded comorbidities, TEVAR survival was comparable between patients with and without CPT codes (56.3 vs 59.5 months, P = .54). The early and late incidence of death varied significantly by aortic disease. Patients with aortic rupture, acute aortic dissection, and aortic trauma had the highest early incidence of death, whereas late survival was highest in patients with acute aortic dissection, aortic trauma, and isolated thoracic aortic aneurysm. Although hospital TEVAR volume was not associated with survival, an independent hospital effect (determined by using a mixed-effect Cox model) associated certain hospitals with a hazard for death 50% of what it was at other hospitals. TEVAR has been applied to a multitude of aortic diseases in the Medicare population; early and late post-TEVAR survival varies by aortic disease. The late incidence of death remains high in TEVAR recipients, although certain aortic diagnoses such as acute aortic dissection, aortic trauma, and isolated thoracic aortic aneurysm were associated with improved late survival. An independent hospital effect, but not hospital volume, is correlated with post-TEVAR survival. Future analyses of TEVAR outcomes using the Medicare database should adjust for underlying aortic diagnoses and the presence of CPT codes. Copyright © 2014 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.
    Journal of Thoracic and Cardiovascular Surgery 10/2014; 149(3). DOI:10.1016/j.jtcvs.2014.10.036 · 3.99 Impact Factor
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    ABSTRACT: Purpose : To report a subgroup analysis comparing safety and effectiveness outcomes in Japanese and non-Japanese patients as part of a prospective, multinational, randomized controlled trial (ClinicalTrials.gov identifier NCT00120406) evaluating a paclitaxel-coated drug-eluting stent (DES) compared to percutaneous transluminal angioplasty (PTA) for treating peripheral artery disease. Methods : Patients were randomly assigned to primary DES or PTA. In the Japanese cohort, 27 patients (21 men; mean age 71.2±9.6 years) were randomized to PTA and 25 patients (19 men; mean age 69.8±10.2 years) to primary DES. In the non-Japanese cohort, 211 patients (131 men; mean age 67.3±10.6 years) were randomized to PTA and 211 patients (136 men; mean age 67.6±9.5 years) to primary DES. Outcome measures included event-free survival (EFS), freedom from target lesion revascularization (TLR), patency, stent fracture, and sustained clinical benefit through 2 years. Results : Safety and effectiveness outcomes were similar in the Japanese and non-Japanese cohorts, although the outcomes in the Japanese cohort treated with primary DES were numerically better. In the DES group, the 2-year EFS was 92.0% vs. 85.0% (p=0.61), freedom from TLR was 96.0% vs. 85.5% (p=0.55), primary patency was 80.0% vs. 74.3% (p=0.61), and clinical benefit was sustained in 88.5% vs. 80.5% of patients (p=0.31) in the Japanese and non-Japanese cohorts, respectively. Stent fractures were seen in 4 of 457 stents at 12 months: 3 in the Japanese cohort and 1 in the non-Japanese cohort. Conclusion : The subgroup analysis comparing Japanese and non-Japanese patients supports the safety and effectiveness of the paclitaxel-coated DES in Japanese patients with stenotic lesions in the femoropopliteal arteries. The lack of major differences associated with ethnicity in these 2-year outcomes supports the validity and value of multinational clinical trials.
    Journal of Endovascular Therapy 10/2014; 21(5):644-653. DOI:10.1583/14-4753.1 · 3.59 Impact Factor
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    ABSTRACT: Under the auspices of the International Society for Neurovascular Disease (ISNVD), four expert panel committees were created from the ISNVD membership between 2011 and 2012 to determine and standardize noninvasive and invasive imaging protocols for detection of extracranial venous abnormalities indicative of chronic cerebrospinal venous insufficiency (CCSVI). The committees created working groups on color Doppler ultrasound (US), magnetic resonance (MR) imaging, catheter venography (CV), and intravascular US. Each group organized a workshop focused on its assigned imaging modality. Non-ISNVD members from other societies were invited to contribute to the various workshops. More than 60 neurology, radiology, vascular surgery, and interventional radiology experts participated in these workshops and contributed to the development of standardized noninvasive and invasive imaging protocols for the detection of extracranial venous abnormalities indicative of CCSVI. This ISNVD position statement presents the MR imaging and intravascular US protocols for the first time and describes refined color Doppler US and CV protocols. It also emphasizes the need for the use of for noninvasive and invasive multimodal imaging to diagnose adequately and monitor extracranial venous abnormalities indicative of CCSVI for open-label or double-blinded, randomized, controlled studies.
    Journal of vascular and interventional radiology: JVIR 09/2014; 25(11). DOI:10.1016/j.jvir.2014.07.024 · 2.15 Impact Factor
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    ABSTRACT: Objective To describe successful endovascular repair of a complex chronic aorto-iliac dissection facilitated by a unique endovascular fenestration technique at the proximal neck. Methods A 57-year-old male presented with disabling lower extremity claudication and a remote history of medically-treated type B aortic dissection. Computed tomographic angiography demonstrated a complex dissection with 7.1-cm false lumen aneurysmal dilatation and significant true lumen compression within bilateral iliac aneurysms and no suitable proximal infrarenal neck free of dissection. Results Using IVUS, guidewires were introduced into true and false lumens. A 9-F sheath was placed on the right side and a 20-G Chiba needle was positioned at the level of the celiac artery and oriented toward the dissection flap. The needle was advanced to puncture the flap and an 0.014-inch wire was then snared from the true to the false lumen. Shearing of the dissection flap in the juxtarenal segment was performed using a “cheese-wire” technique, whereby both ends of the glidewire were pulled caudally in a sawing motion down through the infrarenal neck and into the aneurysm sac. Angiography confirmed absence of residual dissection and perfusion of the visceral vessels via the true lumen. Given the newly created infrarenal neck, standard EVAR was performed and antegrade and retrograde false lumen flow was obliterated from the visceral vessels. Post-operative imaging confirmed aneurysm exclusion, no endoleak, and patent bilateral common iliac arteries with resolution of claudication symptoms and normal ABIs. Conclusions Endovascular management of false lumen aneurysms in the setting of chronic dissection is limited by the ability of stent-grafts to obtain adequate proximal or distal fixation. Endovascular fenestration of these chronic flaps facilitates generation of suitable landing zones, thereby serving as a useful adjunct to standard EVAR.
    Annals of Vascular Surgery 09/2014; 29(1). DOI:10.1016/j.avsg.2014.07.025 · 1.03 Impact Factor
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    ABSTRACT: We describe a case of catheter-based embolization and deactivation of a left ventricular assist device using an Amplatzer plug for a patient demonstrating myocardial recovery after diagnosis of nonischemic cardiomyopathy. This procedure can provide a minimally invasive, low morbidity solution for patients wishing to be separated from left ventricular assist device support who want to avoid invasive surgery for device removal.
    The Annals of Thoracic Surgery 08/2014; 98(2):710-3. DOI:10.1016/j.athoracsur.2013.09.073 · 3.63 Impact Factor
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    ABSTRACT: This trial evaluated thoracic endovascular aortic repair (TEVAR) compared with open surgical repair of descending thoracic aortic aneurysms and large ulcers at 42 international sites. Whereas several studies demonstrate early safety and utility advantages with TEVAR, longer follow-up is important because of concerns about durability of TEVAR. This prospective, nonrandomized study enrolled 160 TEVAR patients treated with the Cook Zenith TX2 and 70 open surgical repair patients. Although follow-up was limited, 5-year mortality rate was similar at 37% for both groups. Aneurysm-related mortality rate was 5.9% with TEVAR compared with 12% with open surgical repair (P = .11). There were no ruptures of the treated aneurysms in either group or open conversions in the TEVAR group. Predefined severe morbidity occurred at a significantly lower rate in TEVAR (21%) compared with open surgical repair (39%; P < .001). Aneurysm growth was seen by core laboratory in 5.9% of patients and endoleak in 5.7% of patients. Secondary intervention rates were similar between TEVAR (8%) and open surgical repair (12%; P = .49) patients. Five-year results indicate similar all-cause mortality and aneurysm-related mortality with TEVAR compared with open repair. There was a persistent reduction of severe complications with TEVAR. Reinterventions occurred with similar frequency. TEVAR with the TX2 is a safe and effective alternative to open surgical repair for the treatment of anatomically suitable descending thoracic aortic aneurysms and ulcers.
    Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 03/2014; 60(1). DOI:10.1016/j.jvs.2014.01.043 · 2.98 Impact Factor
  • Journal of Vascular Surgery 08/2013; 58(2):556. DOI:10.1016/j.jvs.2013.05.055 · 2.98 Impact Factor
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    ABSTRACT: This document by an expert panel of the International Society for Neurovascular Disease is aimed at presenting current technique and interpretation of catheter venography of the internal jugular veins, azygous vein and other veins draining the central nervous system. Although interventionalists agree on general rules, significant differences exist in terms of details of venographic technique and interpretations of angiographic pictures. It is also suggested that debatable findings should be investigated using multimodal diagnostics. Finally, the authors recommend that any publication on chronic cerebrospinal venous insufficiency should include detailed description of venographic technique used, to facilitate a comparison of published results in this area.
    VASA.: Zeitschrift für Gefässkrankheiten. Journal for vascular diseases 05/2013; 42(3):168-76. DOI:10.1024/0301-1526/a000265 · 1.21 Impact Factor
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    ABSTRACT: OBJECTIVE: A prospective, multinational randomized controlled trial (RCT) and a complementary single-arm study evaluated the 2-year safety and effectiveness of a paclitaxel-coated drug-eluting stent (DES) in patients with superficial femoral artery (SFA) lesions. The RCT compared the DES to percutaneous transluminal angioplasty (PTA) and provisional bare metal stent (BMS) placement. BACKGROUND: Local drug delivery for SFA lesions has been investigated with the intent of limiting restenosis similarly to DES for the coronary arteries. One-year outcomes of DES in the SFA are promising but longer-term benefits have not been established. METHODS: In the RCT, patients were randomly assigned to primary DES (n=236) or PTA (n=238). Acute PTA failure occurred in 120 patients, who underwent secondary randomization to DES (n=61) or BMS (n=59). The single-arm study enrolled 787 patients with DES treatment. RESULTS: Compared with the control group, the primary DES group demonstrated significantly superior 2-year event-free survival (86.6% versus 77.9%; p=0.02) and primary patency (74.8% versus 26.5%; p<0.01). In addition, the provisional DES group exhibited superior 2-year primary patency compared with the provisional BMS group (83.4% versus 64.1%; p<0.01) and achieved higher sustained clinical benefit (83.9% versus 68.4%; p=0.05). The 2-year freedom from target lesion revascularization with primary DES was 80.5% in the single-arm study and 86.6% in the RCT. CONCLUSIONS: The 2-year outcomes with the paclitaxel-eluting stent support its sustained safety and effectiveness in patients with femoropopliteal arterial disease, including the long-term superiority of the DES to PTA and to provisional BMS.
    Journal of the American College of Cardiology 04/2013; 61(24). DOI:10.1016/j.jacc.2013.03.034 · 15.34 Impact Factor
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    ABSTRACT: Acute aortic syndromes and traumatic aortic injury are often diagnosed on CT angiography, possibly requiring emergent intervention. Advances in handheld computing have created the possibility of viewing full DICOM datasets from a remote location. We evaluated the ability to diagnose and characterize acute aortic pathologies on CT angiograms of the thorax using an iPhone-based DICOM viewer. This study was performed after Institutional Review Board approval. Fifteen CT angiograms of the thorax in suspected acute aortic syndromes were evaluated by three blinded radiologists on a handheld device using a DICOM viewer. Studies were evaluated for the ability to identify and classify aortic dissection, transection, or intramural hematoma, measure aortic dimensions, and identify mediastinal hematoma, arch variants, and pulmonary pathology. Studies were compared to blinded interpretations on a dedicated PACS workstation. The aortic pathology was correctly identified as aortic transection/pseudoaneurysm (n = 5), type A dissection (n = 2), and type A intramural hematoma (n = 1) by all reviewers, with no false-positive interpretations. This represents a sensitivity and specificity of 100 %. Mediastinal hematoma (n = 6), pneumothorax (five right, three left), and arch vessel involvement (n = 2) were identified in all cases. There was 88.5 % accuracy in identifying arch variants. Measurement of the size of the involved aortic segment was similar on handheld device and PACS workstation; however the adjacent normal aorta was 1.2 ± 1.0 mm larger on the handheld device (p = 0.03). Handheld DICOM viewers may be useful for emergent consultations and triage, and may expedite preprocedure planning to reduce the time interval between diagnostic scan and therapeutic intervention.
    Emergency Radiology 03/2013; DOI:10.1007/s10140-013-1118-8
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    ABSTRACT: This study sought to evaluate the outcomes of drug-eluting stent treatment for femoropopliteal in-stent restenosis (ISR). ISR after femoropopliteal interventions is an increasing problem. Although the role of drug-eluting stents in the treatment of coronary ISR is well defined, no published studies have examined drug-eluting stents in the treatment of femoropopliteal ISR. This study examines 108 patients with 119 ISR lesions who were enrolled in the ZILVER-PTX single-arm study, a prospective, multicenter clinical trial of 787 patients. All patients were treated with paclitaxel-eluting nitinol stents. Mean patient age was 68.3 ± 9.4 years; 61.1% of patients were men. Mean lesion length was 133.0 ± 91.7 mm; 33.6% of lesions were >150 mm long and 31.1% of lesions were totally occluded. Procedural success was achieved in 98.2% of lesions with 2.1 ± 1.2 stents placed per lesion. Primary patency was 95.7% at 6 months and 78.8% at 1 year. Freedom from target lesion revascularization was 96.2% at 6 months, 81.0% at 1 year, and 60.8% at 2 years. Forty patients experienced major adverse events, exclusively target lesion revascularization. Before treatment, 81.1% of patients had Rutherford scores ≥3; at 2 years, 60.9% of patients had Rutherford scores ≤1. Both ankle brachial index and walking impairment questionnaire scores significantly improved following treatment. The 1-year fracture rate of stents used in ISR lesions was 1.2%. No significant risk factors associated with loss of patency were identified. Treatment of femoropopliteal ISR with paclitaxel-eluting stents results in favorable acute, midterm, and long-term outcomes. (Zilver PTX Global Registry [ZILVER-PTX]; NCT01094678).
    JACC. Cardiovascular Interventions 03/2013; 6(3):274-81. DOI:10.1016/j.jcin.2012.12.118 · 7.44 Impact Factor
  • Michael D. Dake
    Journal of Vascular and Interventional Radiology 10/2012; 23(10):1335-1336. DOI:10.1016/j.jvir.2012.08.005 · 2.15 Impact Factor
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    ABSTRACT: Transesophageal echocardiography (TEE) is routinely used in our Institution for monitoring correct positioning of thoracic aortic stent grafts. We present a case of successful endovascular repair of three discrete thoracic aortic aneurysms with Zenith TX2 endovascular stent grafts in an 82-year-old female patient. Our focus is on the increased value of TEE guidance because of the ability of partial stent deployment and manipulation during insertion.
    Annals of Vascular Surgery 08/2012; 26(6):861.e7-9. DOI:10.1016/j.avsg.2012.01.013 · 1.03 Impact Factor
  • Michael D Dake
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    ABSTRACT: Multiple sclerosis (MS) is a chronic inflammatory disorder of the central nervous system (CNS) most commonly characterized by focal areas of myelin destruction, inflammation and axonal transection. The multicentric inflammation and demyelination of the brain and spinal cord are associated with variable neurologic symptoms ranging from mild dysfunction to debilitating. Typically, these symptoms are marked by episodes of clinical worsening followed by improvement. The cause of this disease remains unclear currently, but the underlying etiology is generally considered to be immunologically based. Other factors, including genetic, environmental and infectious influences have been implicated, as well. Now recent studies have proposed that extracranial venous obstruction, termed chronic cerebrospinal venous insufficiency (CCSVI) may have a role in the pathogenesis of MS or many of its associated clinical manifestations. It is postulated that venous narrowing affecting one or more of the jugular veins and/or the azygous vein in the chest may be responsible for abnormal blood flow in the veins draining the brain and spinal cord. The abnormal flow may initiate and/or sustain a local inflammatory response at the blood-brain barrier that promote pathological changes within the CNS. This review presents the history of the relationship between the vascular system and MS and explores the background of basic and clinical investigations that led to the concept of CCSVI.
    Techniques in vascular and interventional radiology 06/2012; 15(2):94-100. DOI:10.1053/j.tvir.2012.02.002
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    ABSTRACT: Endovascular intervention for obstruction to venous drainage of the head and neck is an established treatment for disorders such as superior vena cava syndrome. Some patients with multiple sclerosis have been observed to have anomalies of the veins draining the head and neck. It is possible that some symptoms associated with multiple sclerosis may be secondary to disturbed venous flow. In an uncontrolled clinical series of 40 patients who had been previously diagnosed with multiple sclerosis, anomalies of the venous drainage of the head and neck were observed, including venous stenoses of the internal jugular veins. In 38 of 40 patients, venous stents were placed with restoration of luminal dimensions and abrogation of the venous pressure gradient. The angiographic and hemodynamic improvement was associated with improvement in symptomatology, most particularly in cognitive and constitutional symptoms that may be related to cerebrovenous flow. Serious complications included death in one subject and stent embolization requiring open heart surgery in another. In conclusion, in this series, endovascular intervention to correct venous stenosis associated with multiple sclerosis was associated with improvement in symptoms possibly related to disturbed venous hemodynamics. However, given the serious adverse events in this small series, a randomized clinical trial is required to confirm these findings, and to determine if the procedure has any effect on the progression of multiple sclerosis, or untoward long-term adverse effects.
    Vascular Medicine 04/2012; 17(3):131-7. DOI:10.1177/1358863X12440125 · 1.73 Impact Factor
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    ABSTRACT: To demonstrate the role of endovascular approaches to the ascending aorta in the post-transplant context. Three patients (2 women and 1 man aged 52, 68, and 43 years, respectively) developed pseudoaneurysm of the ascending aorta following thoracic organ transplantation. Due to the prohibitive risk of open surgery in each case, an endovascular repair of the ascending aorta was performed, with implantation of 1 to 3 stent-grafts to span the lesions. Follow-up imaging demonstrated complete exclusion of the pseudoaneurysms, with excellent outcomes at 4 months, 6 months, and 3 years. Stent-grafting of the ascending aorta represents a viable approach to pseudoaneurysm in the post-transplant setting.
    Journal of Endovascular Therapy 02/2012; 19(1):52-7. DOI:10.1583/11-3601.1 · 3.59 Impact Factor
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    ABSTRACT: Device-related complications in the thoracic aorta are partly due to the unavoidable proximal angulation and increased flow-related forces. The present study evaluated the incidence, predictors, and outcome of the complication of infolding with the GORE TAG thoracic endoprosthesis (TAG device) to better understand the factors that might help predict these events. We reviewed all complaints reported to W. L. Gore and Associates (Flagstaff, Ariz) related to device infolding after the use of the GORE TAG device on or before December 2008. Events related to device infolding were evaluated. Reporting physicians and local company representatives were contacted, when necessary, to assemble all available imaging, data, and outcomes related to these case reports. When available, computed tomography images were reviewed to confirm aortic landing zone diameters, which were subsequently compared with the implanted device size. From 1998 through December 2008, device infolding was reported in 139 patients (mean age, 40 ± 17 years; 73.4% men) from 33,289 device implants (reported incidence, 0.4%). Events were noted in implants for trauma (60%), dissection (19%), aneurysm (10%), and other (9%) and unknown (2%) etiologies. In 77 patients with available imaging, the average minimum aortic diameter was 21.4 ± 4.4 mm. The mean device diameter was 28.5 ± 3.5 mm, with an average oversizing of nearly 33%. Of reported patients, 51% were asymptomatic, with the diagnosis being made on routine chest imaging. Time to diagnosis was 76 ± 222 days (median, 9.5 days). Only 16 patients received no intervention after the diagnosis of device infolding, all of whom were asymptomatic. The other 123 patients underwent 135 interventions. Of these, 30 patients (24%) underwent open surgical conversion and complete or partial endograft removal. The other interventions included a variety of endovascular techniques, such as large balloon-expandable stent(s) in 40%, relining with additional endograft(s) in 31%, and repeat ballooning in seven patients. Ten patients died after device infolding, all after one or more attempts to repair the infolded device: five died of symptoms related to the infolding and five secondary to the intervention undertaken to correct the device infolding. TAG device infolding appears to be an infrequent event, primarily occurring in young trauma patients secondary to excessive oversizing and severe proximal aortic angulation. However, there clearly exists a need for devices that treat such patients. As a result, future device designs should consider the compression failure mode when being designed in order to help prevent such events.
    Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 12/2011; 55(3):652-8; discussion 658. DOI:10.1016/j.jvs.2011.09.079 · 2.98 Impact Factor
  • Circulation 12/2011; 125(2):395-467. DOI:10.1161/CIR.0b013e31823299a1 · 14.95 Impact Factor
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    Journal of the American College of Cardiology 12/2011; 59(3):294-357. DOI:10.1016/j.jacc.2011.10.860 · 15.34 Impact Factor
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    ABSTRACT: To report a prospective, single-arm, multicenter clinical study evaluating the Zilver PTX drug-eluting stent for treating the above-the-knee femoropopliteal segment (NCT01094678; http://www.clinicaltrials.gov ). The Zilver PTX drug-eluting stent is a self-expanding nitinol stent with a polymer-free paclitaxel coating. Patients with symptomatic (Rutherford category 2-6) de novo or restenotic lesions (including in-stent stenosis) of the above-the-knee femoropopliteal segment were eligible for enrollment. Between April 2006 and June 2008, 787 patients (578 men; mean age 66.6±9.5 years) were enrolled at 30 international sites. Nine hundred lesions (24.3% restenotic lesions of which 59.4% were in-stent stenoses) were treated with 1722 Zilver PTX stents; the mean lesion length was 99.5±82.1 mm. The 12-month Kaplan-Meier estimates included an 89.0% event-free survival rate, an 86.2% primary patency rate, and a 90.5% rate of freedom from target lesion revascularization. There were no paclitaxel-related adverse events reported. The 12-month stent fracture rate was 1.5%. The ankle-brachial index, Rutherford score, and walking distance/speed scores significantly improved (p<0.001) from baseline to 12 months. These results indicate that the Zilver PTX drug-eluting stent is safe for treatment of patients with de novo and restenotic lesions of the above-the-knee femoropopliteal segment. At 1 year, the overall anatomical and clinical effectiveness results suggest that this stent is a promising endovascular therapy.
    Journal of Endovascular Therapy 10/2011; 18(5):613-23. DOI:10.1583/11-3560.1 · 3.59 Impact Factor

Publication Stats

8k Citations
738.91 Total Impact Points

Institutions

  • 1995–2014
    • Stanford University
      • • Department of Cardiothoracic Surgery
      • • Division of Interventional Radiology
      Palo Alto, California, United States
  • 2008–2013
    • University of Virginia
      • Department of Radiology and Medical Imaging
      Charlottesville, Virginia, United States
  • 1993–2012
    • Stanford Medicine
      • • Falk Cardiovascular Research Center
      • • Division of Interventional Radiology
      • • Program in Human Gene Therapy
      • • Department of Cardiothoracic Surgery
      • • Department of Radiology
      Stanford, California, United States
    • University of Michigan
      • Department of Radiology
      Ann Arbor, Michigan, United States
  • 2003
    • Sapienza University of Rome
      • Department of Radiological, Oncological and Pathological Sciences
      Roma, Latium, Italy
  • 2001
    • Savannah Vascular & Cardiac Institute
      Savannah, Georgia, United States