The Impact of Physician Specialization on Clinical and Hospital Outcomes in Patients Undergoing EVAR and TEVAR

Abstract

Endovascular aneurysm repair (EVAR) and Thoracic endovascular aortic repair (TEVAR) are commonly performed by interventional radiologists, cardiologists, general surgeons, cardiothoracic surgeons, and vascular surgeons, with each specialty having differences in residency structure, operative experience, and subspecialty training. The aim of this study is to evaluate the impact of surgeon specialty on outcomes following EVAR and TEVAR. Patients who underwent EVAR and TEVAR were identified from the 2007 to 2009 Nationwide Inpatient Sample (NIS). Physician identifiers in the NIS were used to determine surgical specialty and operative experience. Multivariate analysis adjusted for mortality risk was used to compare differences in demographics, complications, outcomes, and hospital covariates. A total of 5147 EVARs were identified within the NIS, of which 88.3% were completed by vascular surgeons. There were no significant differences in demographics between the specialties. Cardiothoracic surgeons were more likely to have a postoperative stroke (3.1% vs. 0.2%, odds ratio [OR] 14.6, 95% confidence interval [CI] 1.8-117.8, P<0.05) and cardiac complications (9.4% vs. 2.0%, OR 5.0, 95% CI 1.5-16.6, P<0.01) compared with other specialties. Costs were lowest for vascular surgeons ($32,094), and highest for cardiothoracic surgeons ($41,663, P<0.05). Only vascular surgeons completed more than 10 EVARs per year. A total of 2531 TEVAR cases were completed during the study period, of which 73.8% were completed by vascular surgeons, 15.8% by cardiothoracic surgeons, 8.0% by interventional radiologists, and the remainder by interventional cardiologists and general surgeons. Interventional radiologists had significantly more elective cases (77.8%, P<0.001) than cardiothoracic surgeons (47.2%) or vascular surgeons (53.8%), but had a significantly higher rate of stroke (7.6% vs. 1.1%, P<0.001) and cardiac events (7.2% vs. 3.6%, P<0.001). Length of stay (LOS, 10.7days) and median costs ($52,156) were similar across specialties. Vascular surgeons have a low stroke rate (1.1%, P<0.05 vs. interventional radiologists) and lower rate of cardiac events (3.6% vs. 6.1%, P<0.01) despite caring for patients with higher diagnosis-related group mortality scores (3.6 vs. 3.4, P<0.05). Vascular surgeons appear to have a comparative advantage over other specialties for EVAR because not only are their complication and mortality rates comparable but overall LOS and hospital charges are lower. Furthermore, primarily only vascular surgeons are performing the high volume of annual EVARs necessary to ensure optimal patient outcomes. For TEVAR, vascular surgeons have the lowest overall morbidity compared with the other specialties, and lower mortality compared with cardiothoracic surgeons. These findings may impact patient referral patterns and hospital privileges for providers.