Conversion from endovascular to open abdominal aortic aneurysm repair

Previous studies have found conflicting results regarding the operative risks associated with conversion to open abdominal aortic aneurysm (AAA) repair after failed endovascular treatment (endovascular aneurysm repair [EVAR]). The purpose of this study was to assess the outcome of patients undergoing a conversion, and compare outcomes with standard open AAA repair and EVAR. In addition, we sought out to identify factors associated with conversion.

All patients undergoing a conversion to open repair, and those undergoing standard EVAR and open repair between 2005 and 2013 were included from the National Surgical Quality Improvement Program. Multivariable logistic regression analysis was used to identify factors associated with conversion, and to assess independent perioperative risks associated with conversion compared with standard AAA repair. Subanalysis for factors associated with conversion was performed among patients additionally included in the more detailed targeted vascular module of the National Surgical Quality Improvement Program.

A total of 32,164 patients were included, with 300 conversions, 7188 standard open repairs, and 24,676 EVARs. Conversion to open repair was associated with a significantly higher 30-day mortality than standard open repair (10.0% vs 4.2%; odds ratio [OR], 2.4; 95% confidence interval [CI], 1.6-3.6; P < .001), and EVAR (10.0% vs 1.7%; OR, 7.2; 95% CI, 4.8-10.9; P < .001). Conversion surgery was additionally followed by an increased occurrence of any complication (OR, 1.5; 95% CI, 1.2-1.9 [open]; OR, 7.8; 95% CI, 6.1-9.9 [EVAR]). Factors associated with conversion were young age (OR, 1.2 per 10 years decrease; 95% CI, 1.1-1.4), female gender (OR, 1.5; 95% CI, 1.2-2.0), and nonwhite race (OR, 1.8; 95% CI, 1.3-2.6). Conversely, body mass index >30 was negatively associated with (OR, 0.7; 95% CI, 0.5-0.9). Among anatomic characteristics captured in the targeted vascular data set (n = 4555), large aneurysm diameter demonstrated to be strongly associated with conversion (OR, 1.1 per 1 cm increase; 95% CI, 1.03-1.1).

Conversion to open repair after failed EVAR is associated with substantially increased perioperative morbidity and mortality compared with standard AAA repair. Factors associated with conversion are large diameter of the aneurysm, young age, female gender, and nonwhite race, whereas obesity is inversely related to conversion surgery.