Nancy A Healey

Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States

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Publications (26)63.96 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Utilization of thromboresistant circuits in cardiopulmonary bypass (CPB) surgery has been controversial. However, due to the advantages associated with these types of circuits, we sought to evaluate the efficacy of use of low-dose heparin in conjunction with thromboresistant surfaces, closed perfusion system, elimination of blood-gas interface, maintenance of hematocrit to >25%, and systemic normothermia, with respect to the conventional strategy of non-thromboresistant open circuits with high-dose heparin, during 3 h of CPB in an animal model. Using an open-chest swine model, animals were placed on CPB for 3 h with additional monitoring for 1 h post-CPB. Pigs were randomized into either a heparin-bonded circuit (HBC) group (n = 10) or a non-HBC (NHB) group (n = 10). Hemodynamic, hematologic, and biochemical parameters and multiphoton microscopy were used to compare the two groups. Pigs in the HBC group showed a 38.4% reduction in post-CPB blood loss in comparison with the NHB group (P = 0.0007). Additionally, compared with the HBC group, the NHB group exhibited a 32.7% post-CPB reduction in platelets (P < 0.001) and significant increases in alkaline phosphatase, aspartate aminotransferase, and creatine phosphokinase enzymes (P < 0.0202, P = 0.0015, P < 0.0001; respectively). Multiphoton imaging of the arterial filters revealed no entrapment of RBC, WBC, and platelets in the HBC group, while the filters in the NHB group were clogged by these cells. Utilization of modified perfusion strategy employing low-dose heparin and closed thromboresistant circuits is successful in ameliorating the potential adverse hematologic and pro-inflammatory elements induced with open perfusion system of non-thromboresistant circuits most commonly used in cardiac surgery.
    Journal of Surgical Research 06/2011; 168(1):e7-15. · 2.02 Impact Factor
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    ABSTRACT: Biocompatible surfaces play an important role in the inflammatory response during cardiopulmonary bypass (CBP), with the arterial filter contributing a large surface area of the circuit. Different filter-coating materials designed to improve blood-filter biocompatibility are currently used in CPB circuits. This study evaluates eight biocompatible coatings used for arterial filters and their effects on blood components during circulation. Arterial filters were randomly assigned in eight independent heparin-bonded tubing loops and perfused by a single swine (n=8). Arterial blood was routed simultaneously, but separately, into each circuit and circulated for 30 minutes at 37 degrees C. Blood samples were drawn for CBC, ACT, and TAT III measurements at baseline, post-heparinization and post-circulation. At study completion, filters were imaged using multiphoton microscopy. RBC, platelet, and WBC counts, and TAT III complex were all decreased after 30 minutes of circulation; however, WBC count was the only parameter that showed statistically significant differences between the filters. Circulating WBC reduction ranged from 6% (Carmeda and Trillium) to 41% (Terumo-X-coating) with corresponding microscopic confirmation of increased WBC entrapment. All eight filter coatings altered the blood components to varying degrees. Selection of the most effective filter, in conjunction with a heparin-bonded circuit for CPB, may decrease the intraoperative foreign-surface activation of blood cells.
    Perfusion 12/2009; 24(5):317-23. · 0.94 Impact Factor
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    ABSTRACT: This study elucidates the relationship between intraoperative myocardial acidosis/ischemia and the risk of unplanned hospital readmissions within 30 days and 6 months after cardiac surgery. Myocardial tissue pH (corrected to 37 degrees C: pH(37C)) was monitored in 221 patients during cardiac surgery. Regional myocardial acidosis was defined in terms of specific pH thresholds. Fourteen percent and 27% of the patients were readmitted within 30 days and 6 months postoperatively, respectively. The mean number of readmissions was 1.67 +/- 1.24; pH(37C) <6.85 at the end of cardiopulmonary bypass (CPB) was identified as the threshold most significantly associated with readmission. This threshold was associated with a 6-fold increased risk of readmission within 30 days and a 5-fold increased risk within 6 months. Persistent regional myocardial acidosis after weaning from CPB independently determines unplanned readmission rates up to 6 months postoperatively. This study underscores the importance of avoiding myocardial tissue acidosis during cardiac surgery.
    American journal of surgery 09/2009; 198(3):373-80. · 2.36 Impact Factor
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    ABSTRACT: Injury to the saphenous vein endothelium during harvest impacts patency after coronary artery bypass graft surgery. Many centers are adopting endoscopic saphenous vein harvest (ESVH) instead of using the traditional open saphenous vein harvest (OSVH) technique. Our objective was to compare the effects of ESVH and OSVH on the structural and functional viability of saphenous vein endothelium using multiphoton imaging, immunofluorescence, and biochemical techniques. Ten patients scheduled for coronary artery bypass graft surgery were prospectively identified. Each underwent ESVH for one portion and OSVH for another portion of the saphenous vein. A 1-cm segment from each portion was immediately transported to the laboratory for processing. The vessel segments were labeled with fluorescent markers to quantify cell viability (esterase activity), calcium mobilization, and generation of nitric oxide. Samples were also labeled with immunofluorescent antibodies to visualize caveolin, endothelial nitric oxide synthase, von Willebrand factor, and cadherin, and extracted to identify these proteins using Western blot techniques. All labeling, imaging, and image analysis was done in a blinded fashion. Esterase activity was significantly higher in the OSVH group (p < 0.0001). Similarly, calcium mobilization and nitric oxide production were significantly greater in the OSVH group (p = 0.0209, p < 0.0001, respectively). Immunofluoresence and Western blot techniques demonstrated an abnormal alteration in distribution of caveolin and endothelial nitric oxide synthase in the ESVH group. Our study indicates that ESVH has a detrimental effect on the saphenous vein endothelium, which may lead to decreased graft patency and worse patient outcomes.
    The Annals of thoracic surgery 01/2009; 87(1):62-70. · 3.45 Impact Factor
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    ABSTRACT: Myocardial acidosis during cardiac surgery and postoperative troponin I are markers of myocardial damage that have been shown to predict adverse outcomes. We investigated the relationship between troponin I and myocardial tissue pH, patient outcomes, and cost. Data were prospectively collected on 205 cardiac surgery patients. Troponin I was sampled upon arrival to the intensive care unit (ICU) and every 6 hours thereafter for 24 hours. The lowest pH encountered during aortic cross clamp (LpH) was related to postoperative troponin I on the multivariate level. Multivariate models were constructed to predict adverse events (AE) and cost. LpH was an independent inverse determinant of postoperative troponin I (P = .0067). Troponin I and its interaction with LpH were multivariate predictors of AE (P = .0012; .0001;odds ratio = 6.9, 10.2, respectively). Troponin I independently predicts surgical ICU (SICU) cost (P = .0256). Postoperative troponin I elevation reflects intraoperative myocardial acidosis and damage. The strong relationship between troponin I, AE, and cost indicates the damage incurred is clinically and economically relevant. Strategies to ameliorate intraoperative myocardial tissue acidosis will decrease troponin I release, subsequent AE, and associated costs.
    American journal of surgery 10/2008; 196(5):703-9. · 2.36 Impact Factor
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    ABSTRACT: This study examined the impact of intraoperative myocardial acidosis and adverse postoperative outcomes on the cost of cardiac surgical care. Myocardial tissue pH corrected to 37 degrees C (pH(37C)) was measured in 162 patients with cross-clamp (XC) duration of 119 minutes or longer. Perioperative data and outcomes were collected prospectively. The Veterans Affairs cost accounting system was used to determine the cost of care in a subset of 57 patients. Long XC duration was associated with significantly increased acidosis and adverse postoperative outcomes. The cost of care for patients with adverse outcomes was increased by 110% (P < .0001). Patients with acidosis at the end of reperfusion had significantly (P = .0470) increased costs of care. End reperfusion of myocardial tissue pH(37C) of less than 7.0, diabetes mellitus, and body surface area were significant determinants of postoperative adverse outcomes. Intraoperative myocardial acidosis is a determinant of postoperative adverse outcomes and cost in cardiac surgery. Reducing XC duration and improving intraoperative myocardial protection should improve outcomes and reduce cost.
    American journal of surgery 09/2008; 197(2):203-10. · 2.36 Impact Factor
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    ABSTRACT: The Veterans Affairs' (VA) National Surgical Quality Improvement Program (NSQIP) has been associated with significant reductions in postoperative morbidity and mortality. We sought to determine if NSQIP methods and risk models were applicable to private sector (PS) hospitals and if implementation of the NSQIP in the PS would be associated with reductions in adverse postoperative outcomes. Data from patients (n = 184,843) undergoing major general or vascular surgery between October 1, 2001, and September 30, 2004, in 128 VA hospitals and 14 academic PS hospitals were used to develop prediction models based on VA patients only, PS patients only, and VA plus PS patients using logistic regression modeling, with measures of patient-related risk as the independent variables and 30-day postoperative morbidity or mortality as the dependent variable. Nine of the top 10 predictors of postoperative mortality and 7 of the top 10 for postoperative morbidity were the same in the VA and PS models. The ratios of observed to expected mortality and morbidity in the PS hospitals based on a model using PS data only versus VA + PS data were nearly identical (correlation coefficient = 0.98). Outlier status of PS hospitals was concordant in 26 of 28 comparisons. Implementation of the NSQIP in PS hospitals was associated with statistically significant reductions in overall postoperative morbidity (8.7%, P = 0.002), surgical site infections (9.1%, P = 0.02), and renal complications (23.7%, P = 0.004). The VA NSQIP methods and risk models in general and vascular surgery were fully applicable to PS hospitals. Thirty-day postoperative morbidity in PS hospitals was reduced with the implementation of the NSQIP.
    Annals of surgery 08/2008; 248(2):329-36. · 7.90 Impact Factor
  • Journal of Surgical Research - J SURG RES. 01/2008; 144(2):275-275.
  • Journal of Surgical Research - J SURG RES. 01/2008; 144(2):447-447.
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    ABSTRACT: In patients undergoing cardiac surgery, intraoperative myocardial acidosis, which quantifies regional myocardial ischemia, has been shown to increase the risk of adverse postoperative outcomes. In this study, we sought to determine the course of intraoperative myocardial acidosis and its impact on postoperative survival in patients with diabetes mellitus undergoing cardiac surgery. Intraoperative myocardial tissue pH(37C) was continuously measured in the anterior and posterior left ventricular walls in 264 patients undergoing cardiac surgery; 74 (28.0%) of the patients had diabetes (insulin-dependent diabetes: 54%; non-insulin dependent diabetes: 46%). The shortest time required to reach intraoperative myocardial tissue pH < 6.34 during aortic occlusion and > 6.73 during reperfusion were compared in 3 patient groups: insulin-dependent, non-insulin dependent, and nondiabetic. These pH thresholds have been demonstrated to be associated with adverse postoperative long-term survival. The median times to reach intraoperative myocardial tissue pH(37C) < 6.34 during aortic occlusion were 14, 23, and 36 minutes in the insulin-dependent, non-insulin dependent, and non-diabetic groups, respectively (P = .003). The time taken to reach intraoperative myocardial tissue pH(37C) > 6.73 during reperfusion was similar between the 3 groups. After adjusting for relevant pre- and intraoperative parameters, the risk of developing intraoperative myocardial tissue pH < 6.34 during aortic occlusion was 73% higher in patients with insulin-dependent diabetes mellitus (P = .022) but the same in with patients with non-insulin dependent diabetes mellitus (P = .98) when compared with patients without diabetes. Patients with insulin-dependent diabetes mellitus also had nearly threefold decrease in long-term survival compared with that of patients without diabetes (P = .0007). Patients with insulin-dependent diabetes mellitus undergoing cardiac surgery are at a greater risk of developing intraoperative myocardial acidosis/ischemia and of decreased survival postoperatively compared with patients without diabetes.
    The Journal of thoracic and cardiovascular surgery 06/2007; 133(6):1566-72. · 3.41 Impact Factor
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    ABSTRACT: Either a roller pump or a centrifugal pump can be used in the extracorporeal circuit during surgery with cardiopulmonary bypass. In this study, we assessed the effect of these two pumps on the 24-h post-transfusion survival values of autologous red blood cells (RBC). Fourteen male patients subjected to extracorporeal bypass procedures were studied. In seven patients, the autologous red cells were collected following the cardiopulmonary bypass procedure using the roller pump, and in seven patients, autologous red cells were collected following the cardiopulmonary procedure using the centrifugal pump. The 24-h post-transfusion survival values of the autologous RBC were measured using the 51 disodium chromate/99m technetium double isotope procedure. The effects of the extracorporeal bypass procedures using the roller pump and the centrifugal pump were also assessed by the measurements of hematocrit, platelet count, plasma hemoglobin, and serum lactate dehydrogenase levels. The 51 disodium chromate 24-h post-transfusion survival values of the autologous RBC were similar whether the roller pump or the centrifugal pump was used in the extracorporeal circulation, as were the hematocrit, platelet count, plasma hemoglobin and serum lactate dehydrogenase levels. The 24-h post-transfusion survival values of autologous RBC, measured by the 51 disodium chromate/99m technetium double isotope procedure, were not significantly different, whether the roller pump or the centrifugal pump was used in the extracorporeal circuit using membrane oxygenators during cardiopulmonary surgical procedures.
    Perfusion 01/2007; 21(5):291-6. · 0.94 Impact Factor
  • Journal of Surgical Research - J SURG RES. 01/2006; 130(2):243-243.
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    ABSTRACT: Regional myocardial acidosis in patients undergoing cardiac surgery has been shown to be reflective of regional myocardial ischemia. This study elucidates the relationship between intraoperative regional myocardial acidosis and 30-day postoperative outcomes after cardiac surgery. Intramyocardial tissue pH in the anterior and posterior left ventricular walls was measured in 397 adult patients undergoing valve replacement or coronary revascularization surgery between 1987 and 2001. Dedicated nurses and research assistants prospectively collected preoperative, intraoperative, and outcomes data. Regional myocardial acidosis was defined in terms of pH thresholds identified by recursive partitioning. Adverse 30-day outcome, defined as death or any one of six complications, was the dependent variable in a multivariate logistic regression analysis. A morbidity score was developed on the basis of the sensitivity of each of the six complications in predicting death, and was the dependent variable in a multivariate linear regression analysis. During the period of aortic clamping, a mean intramyocardial tissue pH less than 6.85 was identified to be significant by recursive partitioning, and was encountered in either the anterior or posterior left ventricular wall in 85.4% of patients. After adjusting for preoperative and intraoperative variables, this pH threshold was found to be significantly associated with increased adverse outcomes within 30 days after surgery (p = 0.045). It was also significantly associated with increase in the morbidity score (p = 0.05). Regional myocardial acidosis of a magnitude frequently encountered during aortic clamping is an independent determinant of adverse 30-day outcomes after cardiac surgery. Its reversal by pH-guided myocardial management has the potential of improving postoperative patient outcomes.
    The Annals of thoracic surgery 12/2005; 80(5):1751-7. · 3.45 Impact Factor
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    ABSTRACT: The objective of this study was to identify the determinants of 30-day postoperative mortality and long-term survival after major surgery as exemplified by 8 common operations. The National Surgical Quality Improvement Program (NSQIP) database contains pre-, intra-, and 30-day postoperative data, prospectively collected in a standardized fashion by a dedicated nurse reviewer, on major surgery in the Veterans Administration (VA). The Beneficiary Identification and Records Locator Subsystem (BIRLS) is a VA file that depicts the vital status of U.S. veterans with 87% to 95% accuracy. NSQIP data were merged with BIRLS to determine the vital status of 105,951 patients who underwent 8 types of operations performed between 1991 and 1999, providing an average follow up of 8 years. Logistic and Cox regression analyses were performed to identify the predictors of 30-day mortality and long-term survival, respectively. The most important determinant of decreased postoperative survival was the occurrence, within 30 days postoperatively, of any one of 22 types of complications collected in the NSQIP. Independent of preoperative patient risk, the occurrence of a 30-day complication in the total patient group reduced median patient survival by 69%. The adverse effect of a complication on patient survival was also influenced by the operation type and was sustained even when patients who did not survive for 30 days were excluded from the analyses. The occurrence of a 30-day postoperative complication is more important than preoperative patient risk and intraoperative factors in determining the survival after major surgery in the VA. Quality and process improvement in surgery should be directed toward the prevention of postoperative complications.
    Annals of Surgery 10/2005; 242(3):326-41; discussion 341-3. · 6.33 Impact Factor
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    ABSTRACT: Regional myocardial acidosis, as measured with tissue pH electrodes during cardiac surgery, has been shown to be reflective of regional myocardial ischemia. This study examined the relationship between intraoperative regional myocardial acidosis and long-term survival of patients undergoing cardiac surgery with cardiopulmonary bypass. A total of 496 adult patients who underwent valve replacement, coronary artery revascularization, or both with intraoperative myocardial pH monitoring in the anterior and posterior left ventricular walls were followed up for 3 to 17 years (average 10.2 +/- 4.9 years) for all cause mortality. Regional myocardial acidosis in each patient was defined by the lower of the anterior and posterior wall pH values. A bivariate automatic interaction detection analysis identified three significant regional myocardial acidosis thresholds that affected long-term mortality: pH 37C less than 6.63 before aortic crossclamping, integrated mean pH 37C less than 6.34 during the period of aortic crossclamping, and pH 37C less than 6.73 at discontinuation of cardiopulmonary bypass. Cox proportional hazard regression analysis identified each of these thresholds to be independently determinant of survival, with pH 37C during aortic crossclamping having the highest risk ratio (risk ratio 2.15, 95% confidence interval 1.37-3.37). Raising pH 37C from lower than threshold before aortic crossclamping to higher than threshold during clamping increased the median survival by 40.2%. In adult patients undergoing cardiac surgery with cardiopulmonary bypass, regional myocardial ischemic acidosis before aortic crossclamping, during aortic crossclamping, and at discontinuation of cardiopulmonary bypass are independently associated with reduced long-term postoperative survival. Reversing or avoiding myocardial acidosis during cardiac surgery improves long-term patient survival.
    Journal of Thoracic and Cardiovascular Surgery 03/2005; 129(2):372-81. · 3.53 Impact Factor
  • Advances in Surgery 02/2005; 39:379-453.
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    ABSTRACT: To determine the impact of regional myocardial acidosis encountered during cardiac surgery on the need for inotropic and intra-aortic balloon (IAB) support. Intramyocardial tissue pH(37C) was measured in 247 patients undergoing cardiopulmonary bypass (CPB). Inotropic support (INO) was defined as requiring one or more of norepinephrine/epinephrine/amrinone/dobutamine/>2.5 mug/kg/min dopamine, for at least 45 minutes intraoperatively, and intraoperative or postoperative IAB use. PH (corrected to 37 degrees C, pH(37C)) during surgery was compared in patients who needed INO versus those who did not. Multivariate logistic regression models identified the determinants of INO. Fifty patients (20.2%) required INO intraoperatively. pH(37C) was significantly lower throughout reperfusion in patients needing INO. Preoperative ejection fraction and pH(37C) during reperfusion were identified as independent predictors of INO. This is the first study to show that intraoperative regional myocardial acidosis, a preventable condition, independently determines the need for intraoperative INO. Increased INO is associated with greater postoperative mortality and morbidity.
    The American Journal of Surgery 11/2004; 188(5):474-80. · 2.52 Impact Factor
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    ABSTRACT: Intraoperative regional myocardial acidosis (RMA) during cardiac surgery has been shown to be reflective of regional myocardial ischemia and an independent predictor of adverse postoperative outcomes. This study identifies the determinants of intraoperative RMA. Intramyocardial tissue pH(37C) in the anterior and posterior LV walls was measured in 641 adult patients during cardiac surgery. RMA at two intraoperative periods was quantified as integrated mean pH(37C) < 6.35 during aortic clamping (AC) and pH(37C) < 6.73 at the end of cardiopulmonary bypass (CPB). These pH thresholds were chosen because of their demonstrated relationship to long-term patient survival. Multivariate logistic regression models were constructed. An acidosis prediction score was constructed based on the factors determining RMA at the end of CPB. Independent determinants of RMA during AC were preoperative New York Heart Association class III/IV (P = .007), current smoker (P = .0088), pH(37C) < 6.63 prior to AC (P < .0001), and intraoperative myocardial management technique (P = .0001). Independent determinants of RMA at end of CPB were ASA class IV/V (P = .0042), pH(37C) < 6.63 prior to AC (P = .035), pH(37C) < 6.35 during AC (P = .001), and total duration of CPB > or = 212 minutes (P = .001). RMA during cardiac surgery is determined by patient risk factors, the magnitude of preceding regional myocardial acidosis, and the duration of CPB.
    Surgery 08/2004; 136(2):190-8. · 3.37 Impact Factor
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    ABSTRACT: This is the first blinded, randomized, placebo-controlled clinical trial to evaluate the efficacy of poly-N-acetyl glucosamine (p-GLcNAc) in improving hemostasis in patients undergoing cardiac catheterization. Patients were randomly assigned to have either a placebo-treated (n = 17) or a p-GlcNAc-treated (n = 16) 3 x 3-cm patch topically placed at the femoral insertion site at the completion of their catheterization procedure with a mechanical pressure clamp applied over it. The amount of pressure was measured. Although the placebo group had slightly higher clamp pressure applied to the femoral arterial puncture site at the end of the catheterization procedure (189 +/- 47 vs. 149 +/- 49 mm Hg, p = 0.042), the time to effective hemostasis (16 +/- 7 vs. 10 +/- 3 minutes, p = 0.01) was decreased in the p-GlcNAc group by 37%. The application of p-GlcNAc patches improved hemostasis at the arterial puncture site in patients undergoing cardiac catheterization.
    The Journal of trauma 08/2004; 57(1 Suppl):S38-41. · 2.35 Impact Factor
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    ABSTRACT: Introduction: To determine the role of regional myocardial acidosis (RMA) present at the end of cardiopulmonary bypass on unplanned hospital readmission within 30-days or 6-months after cardiac surgery.Methods: Myocardial tissue pH (corrected to 37degreesC: pH37C) was monitored intraoperatively in 221 patients during cardiac surgery. pH37C < 6.85 in either the anterior or posterior LV wall at the end of cardiopulmonary bypass was used to define RMA. Readmission data was retrospectively abstracted from a centralized VA computerized database. Logistic regression models were constructed to identify predictors of any unplanned readmission and readmissions for cardiac causes only.Results: 13.8% (28 of 203) of patients were readmitted within 30-days and 27.1% (59 of 218) of patients were readmitted within 6-months postoperatively. Cardiac causes accounted for 42.9% (30-days) and 54.2% (6-months) of all readmissions. The mean number of readmissions was 1.67 ± 1.24. Median time to readmission was 15 days (30-days) and 32 days (6-months). RMA was independently associated with a 6 times increased risk of readmission within 30-days and a 4 times increased risk within 6-months (Table). RMA was also independently associated with readmission for cardiac causes (p < 0.05). Risk factorReadmission within 30 days postoperatively (c-index = 0.79)Readmission within 6 months postoperatively (c-index = 0.72)Odds ratio (95% CI)p ValueOdds ratio (95% CI)p ValuePreoperative ASA class IV/V3.10 (1.11, 8.69)0.031——pH37C
    Journal of The American College of Surgeons - J AMER COLL SURGEONS. 01/2004; 199(3):71-71.

Publication Stats

650 Citations
63.96 Total Impact Points

Institutions

  • 2009
    • Beth Israel Deaconess Medical Center
      Boston, Massachusetts, United States
  • 2004–2009
    • Brigham and Women's Hospital
      • Department of Medicine
      Boston, MA, United States
  • 2008
    • U.S. Department of Veterans Affairs
      • Department of Surgery
      Washington, D. C., DC, United States
  • 2005
    • VA Long Beach Healthcare System
      Long Beach, California, United States
  • 2002
    • Mayo Foundation for Medical Education and Research
      • Division of Vascular Surgery
      Scottsdale, AZ, United States
  • 1993–1998
    • Harvard Medical School
      • Department of Surgery
      Boston, MA, United States