The effect of hospital factors on mortality rates after abdominal aortic aneurysm repair

Abstract

Background: Patient factors that contribute to mortality from abdominal aortic aneurysm (AAA) repair have been previously described, but few studies have delineated the hospital factors that may be associated with an increase in patient mortality after AAA. This study used a large national database to identify hospital factors that affect mortality rates after open repair (OAR) and endovascular AAA repair (EVAR) of elective and ruptured AAA.

Methods: A retrospective analysis was completed using the Nationwide Inpatient Sample from 1998 to 2011. International Classification of Disease, Ninth Revision codes were used to identify patients who underwent elective or ruptured AAA repair by OAR or EVAR. The association between mortality and hospital covariates, including ownership, bed size, region, and individual hospital volume for these patients was statistically delineated by analysis of variance, χ(2), and Mann-Kendall trend analysis.

Results: A total of 128,232 patients were identified over the 14-year period, of which 88.5% were elective procedures and 11.5% were performed acutely for rupture. Most hospitals that complete elective OAR do between one and 50 cases, with mortality between 0% and 40%. Hospitals with mortality >40% uniformly complete fewer than five elective OAR cases annually and fall in the bottom 2.5% of all hospitals for mortality. Most hospitals that complete elective EVAR do between one and 70 cases, with mortality between 0% and 13%. Hospitals with mortality >13% uniformly complete fewer than eight elective EVAR cases annually and fall in the bottom 2.5% of all hospitals for mortality. The majority of hospitals that complete OAR or EVAR for ruptured AAA have between 0% to 100% for mortality, indicative of the high mortality risk associated with rupture.

Conclusions: Hospitals that complete fewer than five OARs or eight EVARs annually have significantly greater mortality compared with their counterparts. Improved implementation of best practices, more detailed informed consent to include hospital mortality data, and better regional access to health care may improve survival after elective AAA repair.