Marc L Schermerhorn

Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States

Are you Marc L Schermerhorn?

Claim your profile

Publications (196)889.45 Total impact

  • M.L. Schermerhorn · D.B. Buck · A.J. O'Malley

    No preview · Article · Jan 2016
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective: Type II endoleaks are common after endovascular aneurysm repair (EVAR), but their clinical significance remains undefined and their management controversial. We determined risk factors for type II endoleaks and associations with adverse outcomes. Methods: We identified all EVAR patients in the Vascular Study Group of New England abdominal aortic aneurysm database. Patients were subdivided into two groups: (1) those with no endoleak or transient type II endoleak and (2) persistent type II endoleak or new type II endoleak (no endoleak at completion of case). Patients with other endoleak types and follow-up shorter than 6 months were excluded. Multivariable analysis was used to evaluate predictors of persistent or new type II endoleaks. Kaplan-Meier and Cox regression analysis were used to evaluate predictors of reintervention and survival. Results: Two thousand three hundred sixty-seven EVAR patients had information on endoleaks: 1977 (84%) were in group 1, of which 79% had no endoleaks at all, and 21% had transient endoleaks that resolved at follow-up. The other 390 (16%) were in group 2, of which 31% had a persistent leak, and 69% had a new leak at follow-up that was not seen at the time of surgery. Group 2 was older (mean age, 75 vs 73 years; P < .001) and less likely to have chronic obstructive pulmonary disease (COPD; 24% vs 34%; P < .001) or elevated creatinine levels (2.6% vs 5.3%; P = .027). Coil embolization of one or both hypogastric arteries was associated with a higher rate of persistent type II endoleaks (12 vs 8%; P = .024), as was distal graft extension (12% vs 8%; P = .008). In multivariable analysis, COPD (odds ratio [OR], 0.7; 95% confidence interval [CI], 0.5-0.9; P = .017) was protective against persistent type II endoleak, while hypogastric artery coil embolization (OR, 1.5; 95% CI, 1.0-2.2; P = .044), distal graft extension (OR, 1.6; 95% CI, 1.1-2.3; P = .025), and age ≥ 80 (OR, 2.7; 95% CI, 1.4-5.3; P = .004) were predictive. Graft type was also associated with endoleak development. Persistent type II endoleaks were predictive of postdischarge reintervention (OR, 15.3; 95% CI, 9.7-24.3; P < .001); however, they were not predictive of long-term survival (OR, 1.1; 95% CI, 0.9-1.6; P = .477). Conclusions: Persistent type II endoleak is associated with hypogastric artery coil embolization, distal graft extension, older age, the absence of COPD, and graft type, but not with aneurysm size. Persistent type II endoleaks are associated with an increased risk of reinterventions, but not rupture or survival. This reinforces the need for continued surveillance of patients with persistent type II endoleaks and the importance of follow-up to detect new type II endoleaks over time.
    No preview · Article · Jan 2016 · Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background: Endovascular repair of traumatic thoracic aortic injuries (TTAI) is an alternative to conventional open surgical repair. Single-institution studies have shown a survival benefit with thoracic endovascular aortic repair (TEVAR), but whether this is being realized nationally is not clear. The purpose of our study was to document trends in the increase in use of TEVAR and its effect on outcomes of TTAI nationally. Methods: Patients admitted with a TTAI between 2005 and 2011 were identified in the National Inpatient Sample. Patients were grouped by treatment into TEVAR, open repair, or nonoperative management. Primary outcomes were relative use over time and in-hospital mortality. Secondary outcomes included postoperative complications and length of stay. Multivariable logistic regression was performed to identify independent predictors of mortality. Results: Included were 8384 patients, with 2492 (29.7%) undergoing TEVAR, 848 (10.1%) open repair, and 5044 (60.2%) managed nonoperatively. TEVAR became the dominant treatment option for TTAI during the study period, starting at 6.5% of interventions in 2005 and accounting for 86.5% of interventions in 2011 (P < .001). Nonoperative management declined concurrently with the widespread of adoption TEVAR (79.8% to 53.7%; P < .001). In-hospital mortality after TEVAR decreased during the study period from 33.3% in 2005 to 4.9% in 2011 (P < .001), and an increase in mortality was observed for open repair from 13.9% to 19.2% (P < .001). Procedural mortality (TEVAR or open repair) decreased from 14.9% to 6.7% (P < .001), and mortality after any TTAI admission declined from 24.5% to 13.3% during the study period (P < .001). In addition to lower mortality, TEVAR was followed by fewer cardiac complications (4.1% vs 8.5%; P < .001), respiratory complications (47.5% vs 54.8%; P < .001), and shorter length of stay (18.4 vs 20.2 days; P = .012) compared with open repair. In adjusted mortality analyses, open repair proved to be associated with twice the mortality risk compared with TEVAR (odds ratio, 2.1; 95% confidence interval, 1.6-2.7), and nonoperative management was associated with more than a fourfold increase in mortality (odds ratio, 4.5; 95% confidence interval, 3.8-5.3). Conclusions: TEVAR is now the dominant surgical approach in TTAI, with substantial perioperative morbidity and mortality benefits over open aortic repair. Overall mortality after admission for TTAI has declined, which is most likely the result of the replacement of open repair by TEVAR as well as the broadened eligibility for operative repair.
    No preview · Article · Jan 2016 · Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter
  • Ruby C. Lo · Marc L. Schermerhorn
    [Show abstract] [Hide abstract]
    ABSTRACT: Abdominal aortic aneurysm (AAA) has long been recognized as a condition predominantly affecting males, with sex-associated differences described for almost every aspect of the disease from pathophysiology and epidemiology to morbidity and mortality. Women are generally spared from AAA formation by the immunomodulating effects of estrogen, but once they develop, the natural history of AAAs in women appears to be more aggressive, with more rapid expansion, a higher tendency to rupture at smaller diameters, and higher mortality following rupture. However, simply repairing AAAs at smaller diameters in women is a debatable solution, as even elective endovascular AAA repair is fraught with higher morbidity and mortality in women compared to men. The goal of this review is to summarize what is currently known about the effect of gender on AAA presentation, treatment, and outcomes. Additionally, we aim to review current controversies over screening recommendations and threshold for repair in women.
    No preview · Article · Dec 2015 · Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter
  • Marc L. Schermerhorn · A. James O'Malley · Bruce E. Landon

    No preview · Article · Nov 2015 · New England Journal of Medicine
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background: Pulse pressure is a noninvasive measure of arterial stiffness. Increased pulse pressure is associated with an increased risk of cardiovascular events and death. The effects of pulse pressure on outcomes after endovascular interventions for critical limb ischemia (CLI), however, are unknown. We thus evaluated whether increased preoperative pulse pressure was associated with adverse outcomes and mortality in patients who underwent endovascular tibial artery intervention. Methods: All patients who underwent endovascular tibial intervention for CLI at a single institution from 2004 to 2014 were included in this study. Preoperative pulse pressure was derived from measurements obtained in the holding area before the procedure. Patients were divided into 2 groups on the basis of pulse pressure, <80 or ≥80 mm Hg. Patient demographic characteristics and comorbidities were documented, and outcomes including procedural complications, repeat intervention, amputation, and mortality were recorded. Multivariable logistic regression was used to account for patient demographic characteristics and comorbidities. Results: Of 371 patients, 186 patients had a preoperative pulse pressure <80 mm Hg and 185 had a preoperative pulse pressure ≥80 mm Hg. No significant differences in patient demographic characteristics or comorbidities were identified; however, there was a trend toward older age in patients with increased pulse pressure (70 vs 72; P = .07). In univariate analysis, procedural complications (21% vs 13%; P = .02), reinterventions (26% vs 17%; P < .01), and restenosis (32% vs 23%; P = .03) were more common among patients with pulse pressure ≥80. Procedural complications remained significant in multivariate analysis (odds ratio, 1.8; 95% confidence interval, 1.0-3.1; P = .04). There was no difference in 30-day mortality; however, increased mortality was seen at 5 years of follow-up (odds ratio, 1.6; 95% confidence interval, 1.0-2.5; P = .04) in multivariable analysis. Conclusions: Increased preoperative pulse pressure is associated with procedural complications and increased mortality in patients who undergo endovascular tibial intervention for CLI. It is a marker of increased risk, and might be a suitable target for interventions aimed at improving outcomes in this high-risk population.
    No preview · Article · Nov 2015 · Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective: Lower extremity bypass grafts that develop stenoses are commonly treated with either open surgical or endovascular revision. Vein graft stenoses with unfavorable lesions (multiple lesions, lesions >2 cm in length, lesions in grafts <3 months old, lesions in grafts <3 mm in diameter) fare worse than those with favorable lesions when treated with endovascular therapy. However, it is not known if unfavorable lesions fare better with surgical revision than with endovascular treatment or than favorable lesions treated with surgery. Methods: We performed a retrospective review of 175 vein graft revisions performed at a single institution from 2000 to 2010. Characteristics of lesions treated with surgical and endovascular revision were identified. Cox proportional hazard models were used to identify predictors of revision failure (restenosis >75%, revision, or amputation). Results: Ninety-one failing vein grafts (52%) were treated with surgical revision and 84 with endovascular treatment (48%), with a median follow-up of 30 months. Favorable lesions fared better than unfavorable lesions after endovascular treatment, with 12-month freedom from failure of 59% vs 34% (P < .01), but not after surgical revision (66% vs 62%; P = .90). Unfavorable lesions had better freedom from failure after surgery than endovascular treatment (62% vs 34%; P < .01), and results in favorable lesions were similar (66% vs 59%; P = .57). Conclusions: For the treatment of failing vein grafts, endovascular therapy appears adequate for favorable lesions and surgical revision is more durable for unfavorable lesions.
    No preview · Article · Oct 2015 · Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter

  • No preview · Article · Oct 2015 · Journal of Vascular Surgery
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective: Isolated renal artery aneurysms are rare, and controversy remains about indications for surgical repair. Little is known about the impact of endovascular therapy on selection of patients and outcomes of renal artery aneurysms. Methods: We identified all patients undergoing open or endovascular repair of isolated renal artery aneurysms in the Nationwide Inpatient Sample from 1988 to 2011 for epidemiologic analysis. Elective cases were selected from the period 2000 to 2011 to create comparable cohorts for outcome comparison. We identified all patients with a primary diagnosis of renal artery aneurysms undergoing open surgery (reconstruction or nephrectomy) or endovascular repair (coil or stent). Patients with concomitant aortic aneurysms or dissections were excluded. We evaluated patient characteristics, management, and in-hospital outcomes for open and endovascular repair, and we examined changes in management and outcomes over time. Results: We identified 6234 renal artery aneurysm repairs between 1988 and 2011. Total repairs increased after the introduction of endovascular repair (8.4 in 1988 to 13.8 in 2011 per 10 million U.S. population; P = .03). Endovascular repair increased from 0 in 1988 to 6.4 in 2011 per 10 million U.S. population (P < .0001). However, there was no concomitant decrease in open surgery (5.5 in 1988 to 7.4 in 2011 per 10 million U.S. population; P = .28). From 2000 to 2011, there were 1627 open and 1082 endovascular elective repairs. Patients undergoing endovascular repair were more likely to have a history of coronary artery disease (18% vs 11%; P < .001), prior myocardial infarction (5.2% vs 1.8%; P < .001), and renal failure (7.7% vs 3.3%; P < .001). In-hospital mortality was 1.8% for endovascular repair, 0.9% for open reconstruction (P = .037), and 5.4% for nephrectomy (P < .001 compared with all revascularization). Complication rates were 12.4% for open repair vs 10.5% for endovascular repair (P = .134), including more cardiac (2.2% vs 0.6%; P = .001) and peripheral vascular complications (0.6% vs 0.0%; P = .014) with open repair. Open repair had a longer length of stay (6.0 vs 4.6 days; P < .001). After adjustment for other predictors of mortality, including age (odds ratio [OR], 1.05 per decade; 95% confidence interval [CI], 1.0-1.1; P = .001), heart failure (OR, 7.0; 95% CI, 3.1-16.0; P < .001), and dysrhythmia (OR, 5.9; 95% CI, 2.0-16.8; P = .005), endovascular repair was still not protective (OR, 1.6; 95% CI, 0.8-3.2; P = .145). Conclusions: More renal artery aneurysms are being treated with the advent of endovascular techniques, without a reduction in operative mortality or a reduction in open surgery. Indications for repair of renal artery aneurysms should be re-evaluated.
    No preview · Article · Sep 2015 · Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter

  • No preview · Article · Sep 2015
  • [Show abstract] [Hide abstract]
    ABSTRACT: Randomized trials and observational studies have shown that perioperative morbidity and mortality are lower with endovascular repair of abdominal aortic aneurysm than with open repair, but the survival benefit is not sustained. In addition, concerns have been raised about the long-term risk of aneurysm rupture or the need for reintervention after endovascular repair. We assessed perioperative and long-term survival, reinterventions, and complications after endovascular repair as compared with open repair of abdominal aortic aneurysm in propensity-score-matched cohorts of Medicare beneficiaries who underwent repair during the period from 2001 through 2008 and were followed through 2009. We identified 39,966 matched pairs of patients who had undergone either open repair or endovascular repair. The overall perioperative mortality was 1.6% with endovascular repair versus 5.2% with open repair (P<0.001). From 2001 through 2008, perioperative mortality decreased by 0.8 percentage points among patients who underwent endovascular repair (P=0.001) and by 0.6 percentage points among patients who underwent open repair (P=0.01). The rate of conversion from endovascular to open repair decreased from 2.2% in 2001 to 0.3% in 2008 (P<0.001). The rate of survival was significantly higher after endovascular repair than after open repair through the first 3 years of follow-up, after which time the rates of survival were similar. Through 8 years of follow-up, interventions related to the management of the aneurysm or its complications were more common after endovascular repair, whereas interventions for complications related to laparotomy were more common after open repair. Aneurysm rupture occurred in 5.4% of patients after endovascular repair versus 1.4% of patients after open repair through 8 years of follow-up (P<0.001). The rate of total reinterventions at 2 years after endovascular repair decreased over time (from 10.4% among patients who underwent procedures in 2001 to 9.1% among patients who underwent procedures in 2007). Endovascular repair, as compared with open repair, of abdominal aortic aneurysm was associated with a substantial early survival advantage that gradually decreased over time. The rate of late rupture was significantly higher after endovascular repair than after open repair. The outcomes of endovascular repair have been improving over time. (Funded by the National Institutes of Health.).
    No preview · Article · Jul 2015 · New England Journal of Medicine
  • [Show abstract] [Hide abstract]
    ABSTRACT: The volume and complexity of endovascular procedures are increasing. Multidetector computed tomography (CT) made precise three-dimensional (3D) planning of these procedures possible, but intraoperative imaging, even with the use of modern flat-panel detectors, is limited to two dimensions. Flat detectors, however, allow C-arm cone-beam CT. This technology can be used to generate a 3D data set that can be fused with a preoperative high-resolution CT scan, thus generating a live 3D roadmap. We hypothesized that use of a novel image fusion software, VesselNavigator (Philips Healthcare, Best, The Netherlands), facilitates precise and expeditious procedures and therefore reduces radiation exposure and contrast agent dose. A retrospective review of patients undergoing standard aortobi-iliac endovascular aneurysm repair at our institution between January 2011 and April 2014 was performed. Conventional imaging was compared with VesselNavigator-assisted imaging, and a matched analysis based on body mass index (BMI) was performed because of the dependence of radiation dose on body habitus. Outcome parameters were procedure time, fluoroscopy time, radiation, and contrast agent dose. A total of 75 patients were identified. After matching based on BMI, control and VesselNavigator groups each had 16 patients with BMI of 27.0 ± 3.6 kg/m(2) and 27.0 ± 3.6 kg/m(2), respectively (mean ± standard deviation). R(2) was 6.37 × 10(-7). Radiation dose measured as air kerma was lower with VesselNavigator (1067 ± 470.4 mGy vs 1768 ± 696.2 mGy; P = .004). Fluoroscopy time was shorter (18.4 ± 6.8 minutes vs 26.8 ± 10.0 minutes; P = .01) and contrast agent dose was lower (37.4 ± 21.3 mL vs 77.3 ± 23.0 mL; P < .001) with VesselNavigator compared with control. Procedure time was also shorter with VesselNavigator (80.4 ± 21.2 minutes vs 110.0 ± 29.1 minutes; P = .005). Image fusion using VesselNavigator enhances the functionality of conventional fluoroscopy in standard endovascular aneurysm repair. It reduces radiation exposure to patients and providers. It also limits the amount of contrast agent and shortens the overall procedure length. The benefit of this technology is demonstrated on this typically straightforward procedure but may be even more useful for complex procedures. Copyright © 2015 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.
    No preview · Article · Jun 2015 · Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter
  • [Show abstract] [Hide abstract]
    ABSTRACT: The Stenting with Angioplasty and Protection in Patients at High Risk for Endarterectomy (SAPPHIRE) trial compared carotid endarterectomy (CEA) to carotid artery stenting (CAS) among high-risk patients using a model of risk that has not been validated by previous publications. The objective of our study was to determine the accuracy of this high-risk model and to determine the true risk factors that result in patients being at high risk for CEA. Prospectively collected data for 3098 CEAs between 2003 and 2011 at 20 Vascular Surgery Group of New England (VSGNE) centers were used. SAPPHIRE general inclusion criteria and primary outcomes were assessed. Factors that were associated with the primary outcome by analysis of variance (P < .10) and not linearly dependent, as determined by a Pearson correlation analysis, were further assessed for an independent association by multivariate logistic regression. A risk index model was developed for these significant predictors to accurately define high-risk CEA. The average patient age was 69.9 ± 9.5 years, 60% were male, and 45.7% were asymptomatic. The 1-year composite outcome event rate, defined as postoperative myocardial infarction and stroke or death, was 14.2%. Multivariate analysis (P < .05) found the following independently significant risk factors: age in years (95% confidence interval [CI], 1.0-1.1; P < .001), preadmission living in a nursing home (95% CI, 1.2-6.6; P = .020), congestive heart failure (95% CI, 1.4-2.8; P < .001), diabetes mellitus (DM; 95% CI, 1.1-1.3; P < .001), chronic obstructive pulmonary disease (95% CI, 1.2-1.5; P < .001), any previous cerebrovascular disease (95% CI, 1.1-1.9; P = .003), and contralateral internal carotid artery stenosis (95% CI, 1.0-1.2; P = .001). Three of the SAPPHIRE high-risk criteria-abnormal stress test, recurrent stenosis after CEA, and previous radiotherapy to the neck-were not independently associated with an adverse outcome. Independently significant risk factors not included in the SAPPHIRE criteria are inclusion of ages <80 years, preadmission living in a nursing home, DM, contralateral carotid stenosis, and any previous cerebrovascular accident. The risk index predictors are age in years (40-49: 0 points; 50-59: 2 points; 60-69: 4 points; 70-79: 6 points; 80-89: 8 points), living in a nursing home (4 points), any cardiovascular disease (2 points), congestive heart failure (5 points), chronic obstructive pulmonary disease (3 points), DM (2 points), degree of contralateral stenosis (<50%: 0 points; 50%-69%: 1 point; 70%-near occlusion: 2 points; occlusion: 3 points). High-risk CEA is defined as >13 points, representing adverse outcome rate of 22.5%. SAPPHIRE and other previously reported high-risk CAS inclusion criteria do not include all of the factors found to be independently associated with outcomes. Further studies are required to determine whether CAS is inferior to CEA in high-risk patients using a validated model of risk. In addition, this preoperative assessment includes novel criteria that can be used to stratify risks. Copyright © 2015 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.
    No preview · Article · Jun 2015 · Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter

  • No preview · Article · Jun 2015 · Journal of Vascular Surgery

  • No preview · Article · Jun 2015 · Journal of Vascular Surgery

  • No preview · Article · Jun 2015 · Journal of Vascular Surgery

  • No preview · Article · Jun 2015 · Journal of Vascular Surgery

  • No preview · Article · Jun 2015 · Journal of Vascular Surgery

  • No preview · Article · Jun 2015 · Journal of Vascular Surgery

  • No preview · Article · Jun 2015 · Journal of Vascular Surgery

Publication Stats

3k Citations
889.45 Total Impact Points

Institutions

  • 2015
    • Geisel School of Medicine at Dartmouth
      • Institute for Health Policy and Clinical Practice
      Hanover, New Hampshire, United States
  • 2011-2015
    • Harvard University
      Cambridge, Massachusetts, United States
  • 2005-2015
    • Beth Israel Deaconess Medical Center
      • • Division of Vascular and Endovascular Surgery
      • • Department of Surgery
      Boston, Massachusetts, United States
  • 2011-2014
    • Boston Medical Center
      Boston, Massachusetts, United States
  • 2013
    • The Vascular Group
      Albany, New York, United States
    • Central Maine Medical Center
      Lewiston, Maine, United States
  • 2010-2013
    • University of Massachusetts Boston
      Boston, Massachusetts, United States
    • Centers for Medicare & Medicaid Services
      Baltimore, Maryland, United States
  • 1996-2013
    • Harvard Medical School
      • Department of Anesthesia
      Boston, Massachusetts, United States
  • 2012
    • Beverly Hospital, Boston MA
      Beverly, Massachusetts, United States
  • 2008
    • Harbor-UCLA Medical Center
      Torrance, California, United States
  • 2000-2008
    • Dartmouth–Hitchcock Medical Center
      • Department of Surgery
      LEB, New Hampshire, United States