A 14-year experience with 6 cm as a criterion for surgical treatment of abdominal aortic aneurysm

Abstract

Background It remains unclear when to recommend operation for an asymptomatic abdominal aortic aneurysm (AAA). This study examined a prospective series of patients for whom standard criteria were applied. Methods Some 584 consecutive patients with an AAA of diameter 3 cm or greater detected by ultrasonographic screening have been observed for up to 14 years. Repeat ultrasonographic examinations have been performed at intervals. Surgery was not considered unless the aneurysm measured 6 cm in diameter, expanded at a rate equivalent to at least 1 cm per year, caused the patient symptoms, or an iliac aneurysm was present that required treatment. Results Operation was performed on 127 patients; the majority (80; 63 per cent) had an aneurysm that reached 6 cm in diameter. Use of the above criteria prevented rupture in all but 24 (4 per cent) of the 584 patients over the 14-year interval. Of these 24 patients, 11 were unfit for planned surgery and eight declined operation or follow-up. Rupture in the five remaining patients (1 per cent) who were available for treatment compared favourably with the reported 30-day mortality rate for elective surgical treatment of 1·4–12 per cent. Conclusion Repeated observation is preferable to surgical intervention until an aortic aneurysm measures 6 cm in diameter, expands by 1 cm per annum or causes symptoms.