National outcomes after open repair of abdominal aortic aneurysms with visceral or renal bypass.

Background: We evaluated national outcomes after open repair of abdominal aortic aneurysms (AAAs) with visceral or renal bypass (VRB).

Methods: Using the National Inpatient Sample database from 1993 through 2006, AAA repairs were identified by ICD9 codes for diagnosis of intact AAA combined with a procedure of open AAA repair. VRB patients also had an aortorenal and/or mesenteric bypass or mesenteric endarterectomy. Dissections as well as thoracic and thoracoabdominal aneurysms were excluded. Demographics and comorbidities were noted. Mortality and complications were compared to infrarenal AAA (IRA) repairs without VRB. Predictors of perioperative mortality were analyzed by multivariate logistic regression.

Results: A total of 41,166 VRB and 362,808 IRA repairs were identified. VRB repair volume decreased by 58% and IRA volume decreased by 59% from 1993 to 2006. VRB patients had higher mortality (5.8% vs. 4.4%, p < 0.001) and more complications including acute renal failure (9.5% vs. 6.0%, p < 0.001), acute mesenteric ischemia (2.0% vs. 1.2%), and bowel resection (1.1% vs. 0.8%, p < 0.01). Patients requiring a bowel resection or with acute renal failure were 10 times more likely to die within the hospital stay regardless of repair type. Independent preoperative predictors of mortality were VRB (odds ratio [OR] = 1.3, 95% confidence interval [CI] 1.2-1.5), age (OR = 1.4 per decade, 95% CI 1.4-1.5), chronic renal failure (OR = 5.5, 95% CI 4.9-6.3), congestive heart failure (OR = 7.5, 95% CI 6.1-9.3), and pulmonary disease (OR = 1.2, 95% CI 1.1-1.2).

Conclusion: VRB repair volume decreased per year similarly to open IRA repair volume and may be related to increasing use of endovascular therapy. Mortality after VRB is high and dependent upon age, renal failure, and congestive heart failure. Overall, VRB repair was associated with worsened outcomes; however, this study cannot conclude that avoiding such a repair will improve outcomes. This should be factored into surgical decision making for these patients.