Infrarenal abdominal aortic aneurysm: factors influencing survival after operation performed over a 25-year period.

This report is concerned with the factors influencing survival in 920 consecutive patients submitted to operation for infrarenal abdominal aortic aneurysm during the past 25 years. Rupture had occurred in 60 patients (6.5%) and survival was 77%, which did not vary during the period of study. Of the 860 patients (93.5%) treated for nonrupture, 819 (95%) survived operation. The mortality rate in this group varied from 18%, in the earlier period to 1.43% , in recent years. Risk factors including heart disease, hypertension, and advanced age accounted for 95% of the deaths that occurred within 30 days however, the mortality rate in patients with these problems decreased from 19.2% to 1.9% during the period of study although the average number of patients treated each year with these risk factors increased tenfold. Improvements in operative techniques and experience were responsible for decreasing mortality up to about 1971. Subsequent decrease in mortality was due to improvements in anesthesia, monitoring, and other supportive measures during operation and the early recovery period. Complete survival information was obtained in 816 (99.6%) patients, 191 of whom had been treated for periods over 15 years. Factors influencing long-term survival were associated disease and age at time of operation. Survival in percentage in patients without associated heart disease of hypertension for 5, 10, and 15 years was 84, 49, and 21; with heart disease, it was 54, 34, and 17. The median age of patients in the series was 65.5 years and survival at above intervals according to quartile was less than or equal to 60; 71, 53, and 24; 60 less than age less than or equal to 71; 66, 38, and 18; less greater than 71; 43, 13, and 11.