Early elective open surgical repair of small abdominal aortic aneurysms is not recommended: Results of the UK small aneurysm trial

Abstract

The modern era of aortic aneurysm repair started in AAA 4.0-5.5 cm in diameter. 5 The U.K Small AnEurope. The first successful resection of an abdominal eurysm Trial Participants were 126 vascular surgeons aortic aneurysm, with homograft replacement, was from 93 hospitals who collaborated in a randomised performed in Paris on 25th March, 1951, by Dubost trial to collect the evidence to answer the question: and colleagues, t Homografts were rapidly replaced does early elective surgery or ultrasound surveillance by prosthetic grafts of man-made fibres. Since then provide the better management for patmnts with small prostheses have been developed and standardised, AAA? the operative techniques refined and anaesthesia has In the 4-year period between Autumn 1991 and improved. The number of aneurysms repaired electAutumn 1995, 1090 patients, aged 60-76 years, were lvely each year continues to rise, with procedures m randomised to a treatment policy of either early electEngland and Wales having almost doubled recently, ive surgery (n=563) or a period of ultrasound surfrom 1405 to 2378 in the five years from 1990-1995. 2 velllance (n =527). Ultrasound surveillance was Few have stopped to consider to what extent the continued at regular intervals untd the anaurysm diapatmnt benefits from elective surgical repair of an meter exceeded 5.5 cm, the aneurysm became tender, abdominal aortic aneurysm. Since the start of ultraor the aneurysm grew by > 1 cm in a year. The trial sound screening programmes m the 1980s, more and protocol, together with details of how the trial was more asymptomatic abdominal aortic aneurysms executed, have been published previously in this (AAAs) are being detected. 3 Most of these screenjournal. 5 detected AAAs are small, <5.5 cm in diameter. Should The end points of the UK Small Aneurysm Trial such aneurysms be repaired electlvely? The first evlwere: all cause mortahty; aneurysm related mortality; dence to answer this question comes from Europe. quality of life; costs and cost-effectiveness. The U K. Small Aneurysm Trial reported at the Annual An independent Data Monitoring and Ethics CornMeeting of the Vascular Surgical Society of Great Britmlttee reviewed the progress of the trial after each ain and Ireland in November 1998. 4 The evidence, successive 70 deaths and was empowered to stop the outlined below, indicates that elective open surgical trial at any point, should either one treatment arm repair of an asymptomatic AAA of <5.5 cm in diameter be clearly superior or the 30-day operative mortahty should not be recommended, exceed 5% (allowing for appropriate confidence inThe U.K. Small Aneurysm Trial was established m tervals). The trial participants and Trial Steering Com1991 because many vascular surgeons in Britain were mittee were blind to all results until after the trial uncertain whether elective surgical aneurysm repair closed on 30th June, ] 998. At this time the mean patient should be offered to patients with small asymptomatic follow-up was 4.6 years and 309 deaths had been recorded. At randomisatlon, the baseline characteristics of the 563 patients randomised to early elective surgery and Please address all correspondence to l T Powell, Imperial College School of Medicine, Charmg Cross Hospital, Fulham Palace Road, the 527 patients randomised to ultrasound surveillance London W6 8RF, U K were very similar. The mean age of the surgery group