Acute Intraoperative Conversion from Endovascular to Open vs Planned Open Operation for Abdominal Aortic Aneurysm: A Propensity-Score Matched Study from the American College of Surgeons NSQIP Targeted Database

Document Type

Journal Article

Publication Date



Journal of the American College of Surgeons




BACKGROUND: Evaluating outcomes for acute intraoperative conversion to open surgery during endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) was difficult due to low incidence. This study aimed to compare 30-day outcomes between patients with acute intraoperative conversion during EVAR and planned open surgery, and to identify risk factors associated with acute conversion. METHODS: Patients underwent EVAR or planned open AAA repair were identified in ACS-NSQIP targeted databases 2012-2021. Patients with acute intraoperative conversion during EVAR were selected. A 1:3 propensity-score matching was used to match demographics, baseline characteristics, surgical indications, aneurysm size and extent, and emergency cases between the conversion open and planned open groups. Thirty-day postoperative outcomes were assessed. RESULTS: Out of 20,566 EVAR, 177 (0.86%) had acute intraoperative conversion to open surgery. The conversion open group was matched to 504 out of 5,249 planned open patients. Conversion open and planned open groups had comparable 30-day mortality (23.43% vs 17.46%, p=0.09) and organ system complications including MACE (14.86% vs 10.71%, p=0.17), pulmonary complications (17.71% vs 24.01%, p=0.09), and renal complications (8.57% vs 11.11%, p=0.39). The conversion open group had lower bleeding requiring transfusion (48.57% vs 75.60%, p<0.01), shorter operation time (p<0.01), and shorter length of stay (p<0.01). Other postoperative outcomes did not differ. Risk factors associated with acute intraoperative conversion included ruptured aneurysm with or without hypotension. Protective factors included hypertension and aortic distal aneurysm extent. CONCLUSION: While this study does not endorse a universal "EVAR first" strategy for all patients with AAA, EVAR can be attempted first in eligible AAA patients. Even when EVAR is unsuccessful, intraoperative conversion to open surgery still appears to be safe compared to planned open repair.