Can we achieve better results by operating on smaller abdominal aortic aneurysms?

A small (i.e. less than 5 cm) abdominal aortic aneurysm (AAA) is a problem which faces a vascular surgeon with increasing frequency. CT- and ultrasound examinations that are performed for other suspected diseases often reveal an asymptomatic small AAA. It has been common practice to observe small AAAs until they reach 5-6 cm in diameter. In 1987 the practice of operating on small AAAs as they were diagnosed was introduced. The change towards more aggressive operative strategy was made in order to decrease the number of ruptured AAAs as well as mortality and morbidity rates. This paper compares the results of the more aggressive operative therapy conducted during the period 1987-1991 with the preceding 5 years (1981-1986). A total of 119 patients were seen during this ten year period. 43 had ruptured aneurysms and 76 were elective reconstructions. The patients tended to be older and had more associated diseases in the later period of the study. The mean size of resected AAAs was smaller in the later period but the ratio between ruptured and elective AAAs remained the same throughout. Total 30-day mortality decreased from 6.9% to 4.2%. There was no mortality among patients with electively repaired small AAA. In conclusion, small AAAs can be operated on with a low mortality and morbidity. In this study, however, the change in operative strategy towards a more aggressive direction did not decrease the ratio between ruptured and elective operations. It appeared, that those AAAs with the highest risk of rupture could not be detected by operating on asymptomatic, small aneurysms.