Predictors of perioperative morbidity and mortality in open abdominal aortic aneurysm repair

The major advantage of endovascular abdominal aortic aneurysm repair (EVAR) over open repair (OAR) is improved perioperative morbidity and mortality. Long term results of the two modalities are comparable. We sought to quantify factors predicting perioperative morbidity and mortality in patients undergoing OAR.

Consecutive non-ruptured OAR were analyzed for patient demographic factors, perioperative variables including blood pressure, temperature, and glucose control, intraoperative factors, and complications including wound, pulmonary, renal and cardiac, and 30-day mortality. Uni- and multivariate analysis was performed to determine predictors of morbidity and mortality.

240 elective open AAA repairs over 10 consecutive years were performed. 46% required suprarenal clamping. At least one complication occurred in 47% and 30-day mortality was 5.4%. By multivariate analysis, independent predictors of morbidity (any complication) were suprarenal clamping (OR 1.8, 95% CI 1.1-3.2, p = 0.029), operative time (OR 1.005, 95% CI 1.002-1.008, p = 0.002), and low postoperative temperature (OR 1.6, 95% CI 1.1-2.3, p = 0.025). Multivariate predictors of 30 day mortality included advanced age (OR 1.2, 95% CI 1.1-1.3, p = 0.002) and operative time (OR 1.007, 95% CI 1.001-1.013, p = 0.024). Glucose control did not predict morbidity or mortality.

Control of postoperative temperature is a potentially modifiable factor that may reduce morbidity in patients undergoing open AAA repair, thereby minimizing the early advantage of EVAR.