The epidemiology of surgically repaired aneurysms in the United States

Objective: The purpose of this study was to determine the results of surgery for hospitalized cases of aneurysms in the United States, thereby providing a standard of comparison for new techniques proposed to treat aneurysms. Methods: Data on hospitalized aneurysm cases were collected from the National Hospital Discharge Survey, a comprehensive database of patients hospitalized in the United States for treatment from the years 1984 to 1994. The National Hospital Discharge Survey samples non-federal, acute-care hospitals with an average length of stay of less than 30 days. All the cases had a diagnosis of or a surgical procedure for a non-cerebral aneurysm. Results: In the year 1994, 51,949 non-cerebral aneurysms were repaired in the United States, and 75% of these procedures were abdominal aortic aneurysm (AAA) surgeries. The operative mortality rates for AAA were higher than previously reported from multiinstitutional studies and were found to be 8.4% for elective repair and 68% for emergency AAA repair. The number of aneurysm surgeries per thousand population varied by region: surgery rates were more frequent in the Northeast and less frequent in the West. Surgical volume appeared to decrease for smaller hospitals and increase for larger hospitals for the period between 1990 and 1994. The overall mortality rates for all aneurysm surgeries diminished with hospital size. However, no significant difference was found for the rates of elective AAA repair between hospital sizes. The percentage of men with aneurysms who underwent surgery for repair was significantly higher than for women with aneurysms. In addition, the AAA repair rates increased for men from 1985 to 1994, and the number of women reported with repaired AAAs remained constant. Conclusion: The location of aneurysm, urgency of repair, region, sex, and hospital size are important factors related to patient treatment and outcome. These data provide a standard of comparison against which surgeons can compare their own results, and they provide a benchmark for the evaluation of interventional techniques proposed to treat aneurysms.