MORTALITY RESULTS FOR RANDOMIZED CONTROLLED TRIAL OF EARLY ELECTIVE SURGERY OR ULTRASONOGRAPHIC SURVEILLANCE FOR SMALL ABDOMINAL AORTIC-ANEURYSMS

Background Early elective surgery may prevent rupture of abdominal aor tic aneurysms, but mortality is 5-6%. The risk of rupture seems to be low for aneurysms smaller than 5 cm. We investigated whether prophylac tic open surgery decreased long-term mortality risks for small aneurys ms. Methods We randomly assigned 1090 patients aged 60-76 years, with symptomless abdominal aortic aneurysms 4.0-5.5 cm in diameter to under go early elective open surgery (n=563) or ultrasonographic surveillanc e (n=527). Patients were followed up for a mean of 4.6 years. If the d iameter of aneurysms in the surveillance group exceeded 5 5 cm, surgic al repair was recommended. The primary endpoint was death. Mortality a nalyses were done by intention to treat. Findings The two groups had s imilar cardiovascular risk factors at baseline. 93% of patients adhere d to the assigned treatment. 309 patients died during follow-up. The o verall hazard ratio for all-cause mortality in the early-surgery group compared with the surveillance group was 0.94 (95% CI 0.75-1.17, p=0. 56). The 30-day operative mortality in the early-surgery group was 5.8 %, which led to a survival disadvantage for these patients early in th e trial. Mortality did not differ significantly between groups at 2 ye ars, 4 years, or 6 years. Age, sex, or initial aneurysm size did not m odify the overall hazard ratio. Interpretation Ultrasonographic survei llance for small abdominal aortic aneurysms is safe, and early surgery does not provide a long-term survival advantage. Our results do not s upport a policy of open surgical repair for abdominal aortic aneurysms of 4 0-5.5 cm in diameter.