Michael Belkin

Harvard Medical School, Boston, Massachusetts, United States

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Publications (109)393.41 Total impact

  • Journal of Vascular Surgery - J VASC SURG. 01/2011; 54(4):1228-1228.
  • Circulation 12/2010; 122(24):2583-618. · 15.20 Impact Factor
  • Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 12/2010; 52(6):1616-52. · 3.52 Impact Factor
  • Source
    Neal R. Barshes, Louis L. Nguyen, Michael Belkin
    Journal of Vascular Surgery - J VASC SURG. 01/2010; 52(4):1121-1121.
  • Journal of Vascular Surgery - J VASC SURG. 01/2010; 51(2):528-529.
  • Journal of Vascular Surgery - J VASC SURG. 01/2010; 51(6).
  • Journal of Vascular Surgery - J VASC SURG. 01/2010; 51(6).
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    Michael S Conte, Michael Belkin
    Seminars in Vascular Surgery 12/2009; 22(4):207-8. · 1.02 Impact Factor
  • Michael Belkin
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    ABSTRACT: Patients who suffer failure of a previous infrainguinal bypass graft often present with recurrent ischemia requiring secondary revascularization for limb salvage. These patients pose major challenges for the vascular surgeon. Management strategies vary with the time interval from bypass, the functional status of the patient, the degree of ischemia and the availability of autogenous vein. This article reviews the treatment options for these difficult patients and the results which can be achieved.
    Seminars in Vascular Surgery 12/2009; 22(4):234-9. · 1.02 Impact Factor
  • Michael Belkin
    The Journal of thoracic and cardiovascular surgery 11/2009; 138(5):1257-61. · 3.41 Impact Factor
  • Perspectives in Vascular Surgery 11/2009; 21(3):195.
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    ABSTRACT: Gender and ethnicity are factors affecting the incidence and severity of vascular disease as well as subsequent treatment outcomes. Although well studied in other fields, balanced enrollment of patients with relevant demographic characteristics in vascular surgery randomized controlled trials (RCTs) is not well known. This study describes the reporting of gender and ethnicity data in vascular surgery RCTs and analyzes whether these studies adequately represent our diverse patient population. We conducted a retrospective review of United States-based RCTs from 1983 through 2007 for three broadly defined vascular procedures: aortic aneurysm repair (AAR), carotid revascularization (CR), and lower extremity revascularization (LER). Included studies were examined for gender and ethnicity data, study parameters, funding source, and geographic region. The Nationwide Inpatient Sample (NIS) database was analyzed to obtain group-specific procedure frequency as an estimate of procedure frequency in the general population. We reviewed 77 studies, and 52 met our inclusion criteria. Only 85% reported gender, and 21% reported ethnicity. Reporting of ethnicity was strongly associated with larger (>280 participants), multicenter, government-funded trials (P < .001 for all). Women are disproportionately under-represented in RCTs for all procedure categories (AAR, 9.0% vs 21.5%; CR, 30.0% vs 42.9%; LER, 22.4% vs 41.3%). Minorities are under-represented in AAR studies (6.0% vs 10.7%) and CR studies (6.9% vs 9.5%) but are over-represented in LER studies (26.0% vs 21.8%, P < .001 for all). Minority ethnicity and female gender are under-reported and under-represented in vascular surgery RCTs, particularly in small, non-government-funded and single-center trials. The generalizability of some trial results may not be applicable to these populations. Greater effort to enroll a balanced study population in RCTs may yield more broadly applicable results.
    Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 08/2009; 50(2):349-54. · 3.52 Impact Factor
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    ABSTRACT: Recent evidence suggests disparities exist among racial groups with peripheral arterial disease (PAD). Hispanics (HI) are the fastest growing demographic in the United States, but little outcome data is available for this population. Therefore, we undertook this study to compare the results of autogenous infrainguinal bypass grafting in HI to Caucasians (CA) and African Americans (AA). This was a comparative cohort study of prospectively collected registry data of infrainguinal bypass performed at a tertiary center. Patient demographics and comorbidities, operative indications, bypass graft characteristics, and postoperative courses were analyzed. Cumulative patency rates, limb salvage, mortality, and factors associated with these outcomes were determined using Kaplan-Meier analysis and Cox proportional hazards models. From January 1, 1985, through December 31, 2007, 1646 consecutive patients (1408 CA, 57 HI, and 181 AA) underwent 1646 autogenous infrainguinal reconstructions. HI and AA were younger and more often diabetic than CA but HI had less chronic renal insufficiency (CRI) and dialysis-dependence than AA. AA, but not HI, more commonly underwent bypass for critical limb ischemia (CLI) in comparison to CA (AA 90% vs CA 80%, P < .0001; HI 86%). HI and AA bypass grafts had inflow and outflow distal to that in CA. Perioperative mortality (2.3%) and morbidity were similar between groups. Five-year primary patency (+/- standard error [SE]) was significantly lower in HI compared to CA and similar to that in AA (HI 54% +/- 7% vs CA 69% +/- 1%, P = .02; AA 58% +/- 4%). Cox proportional hazard modeling showed high-risk conduit, age <65, CLI, female gender, and AA race were risk factors for failure of primary patency. Secondary patency of HI grafts, unlike AA, was not different than that in CA. Five-year limb salvage (+/- SE) was significantly lower in HI compared to CA and similar to that in AA (HI 80% +/- 6% vs CA 91% +/- 1%, P = .004; AA 83% +/- 3%). Hispanic ethnicity, CLI, high-risk conduit, age <65, CRI, female gender, and diabetes were significant predictors of limb loss. Autogenous infrainguinal bypass surgery in HI is associated with primary patency and limb salvage inferior to that of CA and similar to that of AA, despite HI rates of CLI equivalent to CA and HI comorbidities less severe than AA. HI ethnicity was an independent predictor of limb loss. Our data provides evidence of outcome disparities in HI treated aggressively for their PAD. Further investigation with regard to biologic and social factors is required to delineate the reasons for these inferior outcomes in HI patients.
    Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 07/2009; 49(6):1416-25. · 3.52 Impact Factor
  • Source
    Michael Belkin, Deepak L Bhatt
    Circulation 06/2009; 119(17):2302-4. · 15.20 Impact Factor
  • William P Robinson, Michael Belkin
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    ABSTRACT: Up to 50% of all popliteal artery aneurysms (PAA) present with acute limb ischemia (ALI). ALI due to PAA is a difficult surgical problem, with a 20% to 60% incidence of limb loss and up to 12% mortality reported in the literature in the last three decades. Imminent limb threat requires emergency infrainguinal reconstruction, preferably with autogenous conduit. ALI due to PAA is limb-threatening, often due to obliteration of the tibial vessels in addition to thrombosis of the PAA itself. Arteriography is needed to define inflow vessel and outflow vessel anatomy followed by thrombectomy of the run-off vasculature to establish an appropriate target for bypass. Patients without evidence of neurologic deficit are best served by formal arteriography. Intraarterial thrombolysis is used to establish an outflow vessel for bypass if no runoff vessels are visible. In general, emergency operations are associated with inferior patency and limb salvage compared to elective procedures. Endovascular exclusion of PAA with covered stent graft is used increasingly in the elective setting and has been reported in patients presenting with limb ischemia. The following discussion outlines our algorithm in managing ALI from PAA and reviews management decisions and results of treatment.
    Seminars in Vascular Surgery 04/2009; 22(1):17-24. · 1.02 Impact Factor
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    ABSTRACT: Endovascular procedure volume has increased rapidly, and endovascular procedures have become the initial treatment option for many vascular diseases. Consequently, training in endovascular procedures has become an essential component of vascular surgery training. We hypothesized that, due to this paradigm shift, open surgical case volume may have declined, thereby jeopardizing training and technical skill acquisition in open procedures. Vascular surgery trainees are required to log both open and endovascular procedures with the Accreditation Council for Graduate Medical Education (ACGME). We analyzed the ACGME database (2001-2007), which records all cases (by Current Procedural Terminology [CPT] code) performed by graduating vascular trainees. Case volume was evaluated according to the mean number of cases performed per graduating trainee. The mean number of total major vascular procedures performed per trainee increased by 174% between 2001 and 2007 (from 298.3 to 519.2). Endovascular diagnostic and therapeutic procedures increased by 422% (from 63.7 to 269.1) and accounted for 93.0% of the increase in total procedures. The number of open aortic procedures (aneurysm, occlusive, mesenteric, renal) decreased by 17.1% (from 49.7 to 41.2), while the number of endovascular aortic aneurysm repair procedures increased by 298.8% (from 16.9 to 50.5). Specifically, open aortic aneurysm procedures decreased by 21.8%, aortobifemoral bypass increased by 3.2%, and open mesenteric or renal procedures decreased by 13%. Infrainguinal bypass procedures remained relatively constant (from 37.6 to 36.5, 2.9% decrease), and the number of carotid endarterectomy procedures performed did not change significantly (from 43.6 to 42.2, 3.2% decrease). Vascular surgery trainees are performing a vastly increased total number of procedures. This increase in total procedure volume is almost entirely attributable to the recent increase in endovascular procedures. Aside from a small decline in open aortic procedures, the volume of open surgical procedures has largely remained stable. It is essential that vascular surgery training programs continue to focus on both endovascular and open surgical skills in order for vascular surgeons to remain the premier specialists to care for patients with vascular disease.
    Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 03/2009; 49(5):1339-44. · 3.52 Impact Factor
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    ABSTRACT: With the increasing use of endovascular aneurysm repair, a greater proportion of open aneurysm repairs in the future are expected to be more complex and require suprarenal cross-clamping. We sought to evaluate the effects of suprarenal (SR) vs infrarenal (IR) aortic cross-clamp position in abdominal aortic aneurysm (AAA) repair in an updated single center series. All elective open AAA repairs performed at our institution between 1990 and 2006 were entered into a prospective database and reviewed retrospectively. Our main stratification variable was SR vs IR. The SR group was further subdivided into those requiring an adjunctive renal revascularization procedure (SR+RRP; n = 54) and those who did not (SR-RRP; n = 117). Univariate and multivariate models were used to analyze the effect of baseline variables and operative variables on our primary endpoint 30-day mortality as well as secondary endpoints such as major adverse events, postoperative decline in renal function (defined as doubling of baseline creatinine to level >2 mg/dL, or new-onset dialysis) and long-term survival. A propensity score model was developed to control for confounding variables associated with the use of an SR cross-clamp. A total of 1020 patients underwent elective AAA repair, of which 849 (83.2%) were IR and 171 (16.8%) were SR. Diabetes (14.6% vs 9.1%, P = .027), hypertension (70.2% vs 61.4%, P = .03), and chronic renal failure (14.0% vs 4.7%, P = .001) were more prevalent in the SR group, and mean aneurysm size was larger (6.0 cm vs 5.6 cm, P = .001). Estimated blood loss was higher (1919 mL vs 1257 mL, P = .001) in the SR group, as was mean length of stay (12.6 days vs 10.7 days, P = .047). Perioperative (30-day) mortality rate was 1.8% for the SR group and 1.2% for the IR group (P = .44). Postoperative decline in renal function was 17.0% in SR vs 9.5% in IR (P = .003), however, new-onset dialysis was rare (0.6% SR, 0.8% IR, P = NS). The combination of SR+RRP was associated with an increased risk for postoperative decline in renal function (14.8% SR+RRP, 4.3% SR-RRP, P = .016). Preoperative renal failure was strongly associated with postoperative renal decline (odds ratio [OR] 8.15, 2.92-22.8, P < .0001). Propensity score analysis demonstrated that the use of an SR cross-clamp was associated with an increased risk for postoperative renal decline (OR 2.66, 1.28-5.50, P = .009). Major adverse events were more prevalent in the SR group compared to the IR group (17.0% vs 9.5%, P = .003). Five-year survival was 69.1% + 1.9% for the IR group and 67.7% + 4.3% for the SR group (P = 0.38) by life table analysis. Suprarenal cross-clamping is associated with low mortality and significant but acceptable morbidity, including postoperative decline in renal function. The results from this series may serve as relevant background data when evaluating emerging branched and fenestrated endograft technologies.
    Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 03/2009; 49(4):873-80. · 3.52 Impact Factor
  • Journal of Vascular Surgery - J VASC SURG. 01/2009; 49(5).
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    ABSTRACT: Evidence suggesting a beneficial effect of cardioprotective medications in patients with lower extremity atherosclerosis derives largely from secondary prevention studies of heterogeneous populations. Patients with critical limb ischemia (CLI) have a large atherosclerotic burden with related high mortality. The effect of such therapies in this population is largely inferred and unproven. The Project of Ex-Vivo vein graft Engineering via Transfection III (PREVENT III) cohort comprised 1404 patients with CLI who underwent lower extremity bypass grafting in a multicenter, randomized prospective trial testing the efficacy of edifoligide for the prevention of graft failure. Propensity scores were used to evaluate the influence of statins, beta-blockers, and antiplatelet agents on outcomes while adjusting for demographics, comorbidities, medications, and surgical variables that may influence drug use. Primary outcomes were major adverse cardiovascular events < or =30 days, vein graft patency, and 1-year survival assessed by Kaplan-Meier method. Potential determinants of 1-year survival were modeled using a multivariate Cox regression. In this cohort, 636 patients (45%) were taking statins, 835 (59%) were taking beta-blockers, and 1121 (80%) were taking antiplatelet drugs. Perioperative major adverse cardiovascular events (7.8%) and early mortality (2.7%) were not measurably affected by the use of any drug class. Statin use was associated with a significant survival advantage at 1 year of 86% vs 81% (hazard ratio [HR], 0.71; 95% confidence interval [CI], 0.52-0.98; P = .03) by analysis of both unweighted and propensity score-weighted data. Use of beta-blockers and antiplatelet drugs had no appreciable impact on survival. None of the drug classes were associated with graft patency measures at 1 year. Significant predictors of 1-year mortality by Cox regression modeling were statin use (HR, 0.67; 95% CI, 0.51-0.90; P = .001), age >75 (HR, 2.1; 95% CI, 1.60-2.82; P = .001), coronary artery disease (HR, 1.5; 95% CI, 1.15-2.01; P = .001), chronic kidney disease stages 4 (HR, 2.0; 95% CI, 1.17-3.55; P = .001) and 5 (HR, 3.4; 95% CI, 2.39-4.73; P < .001), and tissue loss (HR, 1.9; 95% CI, 1.23-2.80; P = .003). Statin use is associated with improved survival in CLI patients 1 year after surgical revascularization. Further studies are indicated to determine optimal dosing in this population and to definitively address the question of relationship to graft patency. These data add to the growing literature supporting statin use in patients with advanced peripheral arterial disease.
    Journal of Vascular Surgery 05/2008; 47(4):774-781. · 2.88 Impact Factor
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    ABSTRACT: Carotid artery stenting (CAS) is an alternative to carotid endarterectomy (CEA) for treating carotid artery stenosis. We conducted a systematic review and meta-analysis of the clinical trials to date comparing these two procedures to determine their relative safety and efficacy. Searches of the Cochrane Controlled Trials Register, MEDLINE, and EMBASE identified two cohort studies and eight randomized, controlled trials (RCTs) comparing CEA and CAS. Meta-analysis was performed for the primary outcome of 30-day stroke or death, using an intention-to-treat analysis. Between-trial heterogeneity was assessed using the chi2 test, and fixed-effects models were used to pool estimates in the absence of heterogeneity. Meta-regression was conducted to investigate potential effect differences by patient, intervention, and trial characteristics. To evaluate the effect of study design and inclusion criteria, sensitivity and subgroup analyses were performed. Ten trials encompassing 3580 patients were analyzed. Patients who underwent CAS had a higher risk of 30-day stroke/death relative to patients who underwent CEA (risk ratio [RR], 1.30; 95% CI, 1.01-1.67). Meta-analysis and meta-regression demonstrated no between-trial heterogeneity. Sensitivity analysis of only RCTs showed similar higher risk for stroke/death (RR, 1.38; 95% CI, 1.06-1.79) in CAS patients. Subgroup analysis of trials enrolling only symptomatic patients showed higher risk of 30-day stroke/death (RR, 1.63; 95% CI, 1.18-2.25), but trials enrolling both symptomatic and asymptomatic patients showed no significant differences (RR, 0.89; 95% CI, 0.59-1.35). Meta-analysis of trials to date shows CAS is associated with higher 30-day risk of stroke/death compared with CEA. Thus, for the patient at average surgical risk, the role of CAS is unproven, especially for symptomatic patients. And for the patient at high surgical risk, the role of any intervention is uncertain in the setting of competing comorbidities. The results of ongoing clinical trials in this area will likely provide additional evidence to support treatment choices for carotid artery stenosis.
    Journal of Vascular Surgery 03/2008; 47(2):343-9. · 2.88 Impact Factor

Publication Stats

1k Citations
393.41 Total Impact Points

Institutions

  • 1995–2014
    • Harvard Medical School
      • Department of Surgery
      Boston, Massachusetts, United States
  • 1994–2014
    • Brigham and Women's Hospital
      • • Division of Vascular Surgery and Endovascular Surgery
      • • Department of Surgery
      • • Department of Medicine
      Boston, Massachusetts, United States
  • 2013
    • Boston Medical Center
      Boston, Massachusetts, United States
  • 2012
    • Baylor College of Medicine
      • Division of Vascular Surgery & Endovascular Therapy
      Houston, TX, United States
  • 2009–2012
    • University of California, San Francisco
      • Division of Vascular & Endovascular Surgery
      San Francisco, CA, United States
  • 2004–2012
    • Partners HealthCare
      Boston, Massachusetts, United States
  • 2011
    • University of Massachusetts Medical School
      Worcester, Massachusetts, United States
  • 2008
    • University of Massachusetts Amherst
      Amherst Center, Massachusetts, United States
  • 2003
    • University of Cincinnati
      Cincinnati, Ohio, United States