Abdominal aortic aneurysms: survival analysis of four hundred thirty-four patients

Cases of 434 patients who underwent surgery for abdominal aortic aneurysms in five surgical departments in Norway have been studied with respect to survival patterns and survival probabilities. Of these, 200 patients (median age 63 years) had elective surgery, 173 patients (median age 69 years) had ruptured aneurysms, and 61 patients (median age 67 years) had impending rupture (i.e., emergency operations were performed, but no rupture was found). The hospital mortality rates in the groups were 3.5%, 59%, and 24.6%, respectively. The general probabilities of survival of these groups have been compared with those of a demographically similar population (standard population). Patients who had elective surgery had a slightly, but significantly, lower survival probabilities than did the standard population, whereas the patients who underwent emergency surgery and who survived the first postoperative month showed no increased risk of dying as compared with the standard population. For the elective surgery group, age had a significant effect on survival, whereas the period of operation did not. In the group with ruptured aneurysms both the age of the patient and the period of operation had significant effects on survival, whereas no such effects were found for patients with impending rupture. The survival probabilities for patients surviving the operation were generally good, with a high 5-year survival rate. The mortality rate for patients with ruptured aneurysms decreased significantly from period I (surgery performed before 1976) to period II (surgery performed in 1976 or later). The survival probabilities for patients of advanced age were relatively good, even for patients who had emergency surgery.