Factors affecting survival after rupture of abdominal aortic aneurysm: effect of size on management and outcome.

Between 1970 and 1985, 172 consecutive patients (146 men, 26 women) underwent repair of ruptured abdominal aortic aneurysms. The mean age was 69.8 years. The overall death rate was 49.4%. The most significant predictors of death were an intraoperative urine output under 100 ml, systolic blood pressure less than 90 mm Hg on admission or in the operating room, cardiac arrest and a history of collapse. Discriminant analysis correctly classified 90% of the survivors and 84% of the nonsurvivors. Aneurysm size was documented in 133 cases; the average diameter was 8.78 cm, and 13 (10%) of the aneurysms were smaller than 6.0 cm. A correct diagnosis was made preoperatively in 46% of these 13 cases compared with 77% overall (p less than 0.05), and the time from arrival to transfer to the operating room was 6.71 versus 2.37 hours (p less than 0.05). The death rate for patients who had the small aneurysms was 77% versus 45% for those with larger aneurysms (p less than 0.06). This study confirms the continuing poor results after repair of ruptured abdominal aortic aneurysms. A subset of patients having small aneurysms (less than 6.0 cm) require an aggressive approach to diagnosis and treatment.