Impact of Obesity on Outcomes after Open Surgical and Endovascular Abdominal Aortic Aneurysm Repair

Background

This study examined impact of obesity on outcomes after abdominal aortic aneurysm repair.

Study Design

Data were obtained from the Veterans Affairs National Surgical Quality Improvement Program. Body mass index (BMI) was categorized according to National Institutes of Health guidelines. Multivariate regression adjusted for 40 other risk factors to analyze trends in complications and death within 30 days.

Results

We identified 2,201 patients undergoing 1,185 open and 1,016 endovascular aneurysm repairs (EVAR) for abdominal aortic aneurysms from January 2004 through December 2005. BMI distribution was identical in both groups and reflected national population statistics: approximately 30% were normal (BMI 18.5 to 24.9), 40% were overweight (25.0 to 29.9), and 30% were obese class I (30.0 to 34.9), II (35.0 to 39.9), or III (≥40.0). After open repair, obesity of any class was independently predictive of wound complications (adjusted odds ratio = 2.4; 95% CI, 1.5 to 5.3; p = 0.002). Class III obesity was also an independent predictor or renal complications (adjusted odds rato = 6.3; 95% CI, 2.2 to 18.0; p < 0.0001) and cardiac complications (adjusted odds ratio = 4.5; 95% CI, 1.1 to 22.9; p = 0.045. After EVAR, obesity (any class) was predictive of wound complications (adjusted odds ratio = 3.1; 95% CI, 1.1 to 8.1; p = 0.026), but not predictive of other complications or death. Between the two types of operation, there were fewer complications and deaths after EVAR compared with open repair across all BMI categories, but outcomes were most disparate among the obese.

Conclusions

Obesity is an independent risk factor that surgeons should consider during patient selection and operative planning for abdominal aortic aneurysm repair. Obese patients appear to particularly benefit from successful EVAR over open repair, but if open repair is required, special attention should be paid to cardiac risk, perioperative renal protection, and aggresive wound infection prevention measures.

Abbreviations and Acronyms: AAA, abdominal aortic aneurysm, AOR, adjusted odds ratio, BMI, body mass index, CPT, Current Procedural Terminology, EVAR, endovascular aneurysm repair, NSQIP, National Surgical Quality Improvement Program, OR, odds ratio