Abdominal aortic aneurysm repair in Veterans Affairs medical centers

Abstract

Purpose: This study was performed to define outcomes after abdominal aortic aneurysm (AAA) repair in Veterans Affairs (VA) medical centers during fiscal years 1991 through 1993.

Methods: With VA patient treatment file data, patients were selected from diagnosis-related groups 110 and 111 and were then classified in a patient management category. In the categories of repair of nonruptured and ruptured AAA, mortality and postoperative complication rates were defined for patients who underwent AAA repair in VA medical centers during the 3-year study period.

Results: Hospital mortality rates were 4.86% (166 of 3419) after repair of nonruptured AAA and 47.0% (126 of 268) after repair of ruptured AAA (p<0.001). Of 292 deaths after AAA repair, 136 (43.2%) followed repair of ruptured AAA, even though ruptured AAA comprised only 7.3% of total AAA surgical volume. AAA repairs were performed at 116 VA medical centers, with 31.8+/-23.1 (range, 1 to 140) procedures performed at each center. Although many lower-volume centers had excellent results, centers that performed >or=32 AAA repairs tended to have lower in-hospital mortality rates after repair of nonruptured AAA than those that performed <or=31 procedures (4.2%+/-3.5% compared with 6.7%+/-7.8%;p<0.05). Poisson regression analysis revealed an inverse relationship between the volume of AAA repairs and individual hospital mortality (p=0.001) and a direct relationship between illness severity and hospital mortality (p=0.008). The proportion of ruptured AAAs treated in a hospital was also directly related to individual hospital mortality rates (p<0.005). Postoperative complications were associated with an increased hospital mortality rate (11.7% with complication compared with 6.5% without; p<0.0001) and length of stay (23.6+/-17.1 days compared with 18.0+/-12.4 days; p<0.0001). In a logistic regression model, increased mortality rates after AAA repair were associated with hospital type (adjusted odds ratio [OR]=0.6), increasing age (OR=1.1), patient management category severity score (OR=2.2), hemorrhage (OR=2.3), myocardial infarction (OR=2.6), disseminated intravascular coagulation (OR=4.7), AAA rupture (OR=6.0), postoperative shock (OR=10.7), cardiopulmonary arrest (OR=15.4), central nervous system complications (OR=16.0) and urologic complications (OR=2.4).

Conclusions: Mortality rates after AAA repair in VA hospitals were comparable with those previously reported in other large series. Outcomes for veterans with AAA may improve by referring patients eligible for elective repair to VA medical centers with a greater operative volume or to lower-volume centers that have had excellent results.