Research Profile: Marc L. Schermerhorn, MD

Marc L. Schermerhorn, MD

George H.A. Clowes, Jr. Professor of Surgery, Harvard Medical School


Chief, Vascular and Endovascular Surgery, BIDMC

Research Group

Thomas C. Bodewes, MD
Jeremy D. Darling, BA, MS
Sarah E. Deery, MD, MPH
Chun Li, MD
Patric Liang, MD
Thomas F.X. O’Donnell, MD
Alexander Pothof, MD
Katie E. Shean, MD
Peter A. Soden, MD
Nicholas J. Swerdlow, MD
Klaas Ultee, MD, PhD
Sara L. Zettervall, MD

Research Focus

My clinical research group has an active interest in vascular surgery outcomes research on a local and national level. As emerging technologies evolve the way we practice medicine, comparative effectiveness research has been instrumental in the identification of best practices from among an increasingly complex set of therapeutic options. Our main interest is to compare outcomes after open surgery and endovascular surgery for a variety of vascular diseases, including aortic aneurysms, carotid disease, and lower extremity arterial disease, in order to help guide patient selection for each type of procedure. We utilize a wide range of observational, registry, and administrative data from real-world settings to better understand the impact of vascular treatments on disease processes.

Our experience at BIDMC, boasting the world’s largest series of distal bypass and tibial angioplasty procedures, provided rich data from which we have published on the effectiveness of primary endovascular therapy for critical limb-threatening ischemia and the benefits of statin dose intensities. We have used our institutional experience with novel imaging systems to show reduced radiation exposure and contrast dose for patients and providers. Joining other institutions in the region and nationally, we are an active participant in the Vascular Study Group of New England (VSGNE) and the Vascular Quality Initiative (VQI). These large databases provide detailed procedural and patient-related information from which we have investigated regional differences in patient selection, treatment, and outcomes of abdominal aortic aneurysms (AAA), carotid artery stenosis, and peripheral arterial disease (PAD), among other vascular diseases. We have developed and published work on risk prediction models that can be used in real-world settings to guide physicians in counseling a patient on his/her individual risk of surgery. Through the VQI as well as other databases such as the National Surgical Quality Improvement Project (NSQIP), we shed light on disparities in presentation, treatment selection, and outcomes across both genders and racial groups. 

In addition, administrative data such as the Nationwide Inpatient Sample (NIS), a 20% sampling of all inpatient admissions, and the State Ambulatory Surgery Databases (SASD), a database of all ambulatory surgical encounters by state, have been invaluable in addressing population-based clinical questions, including the epidemiologic trends in the diagnosis and treatment of acute and chronic mesenteric ischemia. Importantly, we have partnered with the Centers for Medicaid and Medicare Services (CMS) to obtain Medicare data for the study of open versus endovascular AAA management, including a comparison of different endovascular stent grafts for AAA repair. We have also demonstrated that late rupture after endovascular repair is a subsisting concern that merits further research. Finally, we have also combined data from several of these sources to comment on data quality, as in our review of the accuracy of administrative data versus clinical data for assignment of neurologic symptom status in patients undergoing carotid revascularization. Expertise in the use of these datasets against the backdrop of our busy clinical practice has allowed our group to produce tangible improvements in the management of vascular disease by translating clinical issues into tangible research questions.

Accomplishments 2016-2017

With over 55 peer-reviewed publications and over 35 presentations* at national and regional society meetings and international symposia in the last two years, my research group has continued to make significant contributions to vascular surgery in the area of comparative effectiveness research. This rich clinical activity has facilitated our participation in multi-center clinical trials in the areas of endovascular abdominal aortic aneurysm repair, best treatment for critical limb-threatening ischemia, and management of carotid artery atherosclerotic disease. Such activity has kept our Division of Vascular and Endovascular Surgery at the cutting edge of new advances in endovascular surgery and positioned us well to report on the effectiveness of these techniques in the literature.

Beyond our institution, I have taken on leadership positions in the Vascular Study Group of New England (VSGNE) and the Vascular Quality Initiative (VQI), innovative quality-improvement initiatives at the regional and national level, respectively. The VSGNE, a consortium of over 30 regional hospitals, collects granular clinical data across institutions from which participants have published novel insights on the management of vascular diseases. The success of the VSGNE has provided a model for quality-improvement efforts nationally through the formation of the VQI, a cooperative of 18 regional quality groups in the U.S. and Canada, and endorsed by the Society for Vascular Surgery. As a member of the Executive and Research Advisory Committees for both organizations, I have worked with our research group to develop projects utilizing these data, resulting in many peer-reviewed publications.

* Vascular Annual Meeting for the Society for Vascular Surgery (9 presentations in 2016 and 5 presentations in 2017), and the Society for Clinical Vascular Surgery, Vascular Annual Symposium (11 presentations in 2016 and 10 presentations in 2017), Charing-Cross Symposium 2017 (2 plenary talks)

Teaching, Training, and Education

Under my mentorship, our research group has welcomed a number of tremendously productive clinical research fellows and PhD candidates in vascular surgery over the past years. Research fellows have come from our own general surgery residency as well as prestigious residency programs around the country. PhD candidates have come through an exciting international research exchange relationship with the University Medical Center Utrecht in the Netherlands, now in its seventh year of existence. In addition, we have developed research collaborations with Toronto, Rotterdam, Amsterdam, and Milan. All research fellows receive formal instruction in research methods and statistics through the Harvard T.H. Chan School of Public Health, and have gone on to present our work at national meetings in vascular surgery.

Selected Research Support

Carotid revascularization and medical management for asymptomatic carotid stenosis trial (CREST-2), NINDS, 2016-2017; PI: Marc L Schermerhorn, MD

Randomized, multicenter, controlled trial to compare best endovascular versus best surgical therapy in patients with critical limb ischemia (BEST-CLI); NHLBI, 2014-2017, Co-PI: Marc L. Schermerhorn, MD (PI: Allen D. Hamdan, MD)

Harvard/Longwood Training Grant in Vascular Surgery, NIH; Co-Investigator: Marc L. Schermerhorn, MD (PI: Frank LoGerfo, MD)

Selected Publications

O'Donnell TFX, Deery SE, Darling JD, Shean KE, Mittleman MA, Yee GN, Dernbach MR, Schermerhorn ML. Adherence to lipid management guidelines is associated with lower mortality and major adverse limb events in patients undergoing revascularization for chronic limb-threatening ischemia. J Vasc Surg 2017;66(2):572-578.

Deery SE, Soden PA, Zettervall SL, Shean KE, Bodewes TC, Pothof AB, Lo RC, Schermerhorn ML. Sex differences in mortality and morbidity following repair of intact abdominal aortic aneurysms. J Vasc Surg 2017;65(4):1006-1013.

Soden PA, Zettervall SL, Deery SE, Hughes K, Stoner MC, Goodney PP, Vouyouka AG, Schermerhorn ML; Society for Vascular Surgery Vascular Quality Initiative. Black patients present with more severe vascular disease and a greater burden of risk factors than white patients at time of major vascular intervention. J Vasc Surg 2018;67(2):549-556.

Pothof AB, Bodewes TCF, O'Donnell TFX, Deery SE, Shean K, Soden PA, de Borst GJ, Schermerhorn ML. Preoperative anemia is associated with mortality after carotid endarterectomy in symptomatic patients. J Vasc Surg 2018;67(1):183-190.

Deery SE, Schermerhorn ML. Open versus endovascular abdominal aortic aneurysm repair in Medicare beneficiaries. Surgery 2017;162(4):721-731.

Zettervall SL, Deery SE, Soden PA, Shean K, Siracuse JJ, Alef M, Patel VI, Schermerhorn ML; Vascular Study Group of New England. Editor's Choice - Renal complications after EVAR with suprarenal versus infrarenal fixation among all users and routine users. Eur J Vasc Endovasc Surg 2017;54(3):287-293.  

Dr. Schermerhorn's Harvard Catalyst Profile