ABDOMINAL AORTIC-ANEURYSM RUPTURE RATES - A 7-YEAR FOLLOW-UP OF THE ENTIRE ABDOMINAL AORTIC-ANEURYSM POPULATION DETECTED BY SCREENING

Purpose: The goal of the current study was to identify the risk of rup ture in the entire abdominal aortic aneurysm (AAA) population detected through screening and to review strategies for surgical intervention in light of this information. Methods: Two hundred eighteen AAAs were detected through ultrasound screening of a family practice population of 5394 men and women aged 65 to 80 years. Subjects with an AAA of les s than 6.0 cm in diameter were followed prospectively with the use of ultrasound, according to our protocol, for 7 years. Patients were offe red surgery if symptomatic, if the aneurysm expanded more than 1.0 cm per year, or if aortic diameter reached 6.0 cm. Results: The maximum p otential rupture rate (actual rupture rate plus elective surgery rate) for small AAAs (3.0 to 4.4 cm) was 2.1% per year, which is less than most reported operative mortality rates. The equivalent rate for aneur ysms of 4.5 to 5.9 cm was 10.2% per year. The actual rupture rate for aneurysms up to 5.9 cm using our criteria for surgery was 0.8% per yea r Conclusion: In centers with an operative mortality rate of greater t han 2%, (1) surgical intervention is not indicated for asymptomatic AA As of less than 4.5 cm in diameter, and (2) elective surgery should be considered only for patients with aneurysms between 4.5 and 6 cm in d iameter that are expanding by more than 1 cm per year or for patients in whom symptoms develop. In centers with elective mortality rates of greater than 10% for abdominal aortic aneurysm (AAA) repair, the benef it to the patient of any surgical intervention for an asymptomatic AAA of less than 6.0 cm in diameter is questionable.