This is the Scientific Surgery Archive, which contains all randomized clinical trials in surgery that have been identified by searching the top 50 English language medical journal issues since January 1998. Compiled by Jonothan J. Earnshaw, former Editor-in-Chief, BJS
Risk factors for aneurysm rupture: results from the UK small aneurysm study and trial. BJS 2000; 87: 500-500.
Published: 6th December 2002
Authors: R. M. Greenhalgh, L. C. Brown, J. T. Powell
Background
The UK Small Aneurysm Trial has shown that ultrasonographic surveillance is a safe management option for patients with small abdominal aortic aneurysms (4·0–5·5 cm in diameter), with an annual rupture rate of 1 per cent. In this study risk factors associated with aneurysm rupture have been investigated using both patients randomized into the UK Small Aneurysm Trial and those monitored for aneurysm growth in the associated study.
Method
The cohort of patients included 1090 from the trial and 1167 from the associated study. In this cohort of 2257 patients (79 per cent men), aged 59–77 years, 103 instances of abdominal aortic aneurysm rupture were identified during the 7‐year follow‐up (1991–1998). The relationship between rupture and ten prespecified risk factors (including age, sex, aneurysm diameter, smoking status, plasma cholesterol, lung function and ankle: brachial pressure index) was investigated using Kaplan–Meier survival and Cox regression analysis.
Results
Almost all patients (98 per cent) had initial aneurysm diameters in the range 3–6 cm and the majority of ruptures (76 per cent) occurred in patients with aneurysms known to be larger than 5 cm in diameter. Kaplan–Meier survival and Cox regression analysis were used to identify baseline risk factors associated with aneurysm rupture. After 3 years, the annual rate of aneurysm rupture was 2·2 (95 per cent confidence interval 1·7–2·8) per cent. The risk of rupture was independently and significantly associated with female sex (P < 0·001), larger initial aneurysm diameter (P < 0·001), lower FEV1 (P = 0·004), current smoking (P = 0·01) and higher mean blood pressure (P = 0·01). Age, body mass index, serum cholesterol concentration and ankle: brachial pressure index were not associated with an increased risk of aneurysm rupture.
Conclusion
Within this cohort of patients women had a threefold higher risk of aneurysm rupture than men. Effective control of blood pressure and cessation of smoking are likely to diminish the risk of rupture. © 2000 British Journal of Surgery Society Ltd
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