Open Abdominal Aortic Aneurysm Repair Is Associated with Higher Mortality Among Nonobese Patients and Higher Risk of Deep Wound Infections Among Obese Patients

Background: Prevalence of obesity in the United States is increasing. The impact of obesity on outcomes after endovascular and open abdominal aortic aneurysm (AAA) repair is largely unknown. The purpose of this analysis was to compare the postoperative outcomes between obese and nonobese patients after these operations. Methods: The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database from years 2013-2015 was analyzed. Preoperative, intraoperative, and postoperative variables were compared between obese and nonobese patient groups. Then obese and nonobese patients were divided into 2 groups each, based on the type of surgery (endovascular repair of abdominal aortic aneurysms (EVAR) versus. open AAA repair), and the outcomes were compared. Then multivariant analysis was used to compare impact of operative modality on outcomes for obese and nonobese patients. Results: A total of 6,859 patients (men 80%, women 20%) underwent surgical procedures for AAA during this time period. Among these patients, 2,218 (32.3%) had body mass index (BMI) >= 30, and 4,641 (67.7%) had BMI <30. Obese patients were less likely to be > 80 years old, women, nonwhites, and smokers. Obese patients had lower mortality and higher risk of deep wound infections after surgery (P < 0.05). Among the obese patients, 83.1% underwent EVAR and 16.9% underwent open AAA repair; patients undergoing EVAR had shorter operative times, shorter length of hospital stays, and mortality (P < 0.05). Among nonobese patients, 81% underwent EVAR and 19% underwent open AAA repair. Patients undergoing EVAR had shorter duration of operation, length of hospital stay, and mortality (P < 0.05). Overall, mortality was the highest among nonobese patients undergoing open AAA repair (odds ratio (OR) 0.66, confidence interval (CI) 0.44-0.99, P < 0.05). Incidence of deep wound infections was the highest among obese patients undergoing open AAA repair (OR 4.3, CI: 1.2-14.6, P < 0.05). Conclusions: Nonobese patients have high mortality after open AAA repair, and obese patients have higher incidence of deep wound infections after open AAA repair. For patients deemed appropriate anatomic candidates, EVAR should be preferred for nonobese patients to improve mortality and for obese patients to reduce the incidence of deep wound infections.