Results of elective abdominal aortic aneurysm repair in the 1990s: A population-based analysis of 2335 cases

Objective: The safety and efficacy of conventional abdominal aortic aneurys m (AAA) repair are undergoing increased examination in parallel with the de velopment of less invasive repair methods. Because most published studies o f elective AAA repair report operations performed in tertiary referral inst itutions and thus may not reflect the outcome in the surgical community at large, the current population-based study was undertaken to document the re sults obtained across a broad spectrum of clinical practice in a defined ge ographic area and to examine the factors that influence the outcomes. Methods: The Maryland Health Services Cost Review Commission database was u sed to identify all the elective AAA repairs that were performed in all the nonfederal acute care hospitals in the state from 1990 to 1995. Results: Elective AAA repair was performed on 2335 patients (mean age, 70.4 years) in 46 of the 52 (88%) nonfederal acute care hospitals in the state, including seven high-volume (>100 cases), nine moderate-volume (50 to 99 c ases), and 30 low-volume (<50 cases) institutions. The in-hospital mortalit y rate was 3.5% and increased significantly with advancing age: less than 6 5 years, 2.2%; 65 to (59 years, 2.5%; 70 to 79 years, 3.5%; and more than 8 0 years, 7.3% (P =.002). Mortality rates were higher for women (4.5% vs 3.2 %; P =.17), for blacks (6.7% vs 3.2%; P =.046), and for patients with renal failure (11.8% vs 3.4%; P =.11) but not for patients with hypertension, di abetes, heart disease, and pulmonary disease. The operative mortality rate was inversely correlated with hospital volume (4.3% in low-volume hospitals , 4.2% in moderate-volume hospitals, and 2.5% in high-volume hospitals; P = .08), although no differences were noted in the mean ages or comorbidity le vels of patients who underwent operations in these three hospital populatio ns. The operative mortality rate was inversely correlated with the experien ce of the individual surgeon: one case, 9.9%; two to nine cases, 4.9%; 10 t o 49 cases, 2.8%; 50 to 99 cases, 2.9%; and more than 100 cases, 3.8% (P =. 01). Multivariate analysis results identified patient age (P =.002), low ho spital volume (P =.039), and very low surgeon volume (P =.01) as independen t predictors of operative mortality. The mean length of stay and mean hospi tal charges were 10.6 days and $17,589 and decreased with increasing surgeo n volume: one case, 22.7 days/$32,800; two to nine cases, 10.6 days/$18,509 ; 10 to 49 cases, 10.0 days/$16,611; 50 to 99 cases, 10.9 days/$17,843; and more than 100 cases, 9.6 days/$16,682 (P<.0001/P<.0001). Conclusion: Elective AAA repair is a safe procedure in contemporary practic e in Maryland. Operative risk is increased among the elderly and when opera tions are performed by surgeons with very low volumes or in low-volume hosp itals. Hospital lengths of stay were shorter and charges were lower when el ective AAA repair was performed by surgeons with higher volumes.