Research Profile: Marc L. Schermerhorn, MD

About Dr. Schermerhorn

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

Benjamin Allar, MD
Jane Cheng, MD
Kirsten Dansey, MD, MPH
Jeremy D. Darling, BA, MS
Sarah E. Deery, MD, MPH
Livia de Guerre, MD
Chun Li, MD, MPH
Jennifer Li, MD
Patric Liang, MD
Jinny Lu, MD
Christina Marcaccio, MD
Thomas F.X. O’Donnell, MD
Priya B. Patel, MD
Alexander Pothof, MD
Peter A. Soden, MD
Lucas Souza-Mota, MD
Nicholas J. Swerdlow, MD
Klaas Ultee, MD, PhD
Rens Varkevisser, MD
Jacqueline Wade, MD
Winona Wu, MD
Cecilia Yao, MD
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, nationally, and internationally, we are an active participant in the Vascular Study Group of New England (VSGNE), the Vascular Quality Initiative (VQI), and the International Registry of Acute Aortic Dissection (IRAD). These large databases provide detailed procedural and patient-related information from which we have investigated 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 sex and racial/ethnic groups.

In addition, administrative data such as the Nationwide Inpatient Sample (NIS), a 20% sampling of all inpatient admissions, have been invaluable in addressing population-based clinical questions including 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 to study 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 concern that merits further research. Finally, we have combined data from several of these sources to comment on data quality, as in our review of the accuracy of administrative versus clinical data for assignment of neurologic symptom status in patients undergoing carotid revascularization. We also compared the accuracy of administrative versus quality improvement data for AAA demographics and outcomes. 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 meaningful research questions.


With more than 34 peer-reviewed publications and more than 40 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 (10 presentations in 2019 and 5 presentations in 2020), the Society for Clinical Vascular Surgery, Vascular Annual Symposium (7 presentations in 2019, the 2020 meeting was cancelled due to COVID-19), New England Society of Vascular Surgery (4 presentations in 2019 and 2 presentation in 2020), Vascular Society Group of New England (6 presentations in 2019) and the European Society for Vascular Surgery (6 presentations in 2020).

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 and vascular surgery residency programs 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 ninth 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 & Publications