[Abdominal aortic aneurysm discovered in a patient with renal insufficiency. A decision analysis]

Decision analysis is an explicit and quantitative technique which is particularly well suited for medical problems involving multiple complex clinical features. In this article, a decision analysis model was used to measure the risks and benefits between different therapeutic options, for a patient with a 4 cm diameter asymptomatic abdominal aortic aneurysm and concomitant end-stage renal failure. A Markov model was built to stimulate the natural history of abdominal aortic aneurysm, its risk of rupture, and the age-dependent dialysis-related mortality. Despite end-stage renal disease that limits life expectancy and increases the surgical risk, the model suggests that surgical resection of the aneurysm (immediate, or delayed if the diameter exceeds 5 cm in diameter) would result in greater life expectancy compared with therapeutic abstention unless the surgical risk exceeds 8.5% and 22%, respectively. Moreover, the gain in life expectancy between immediate and delayed surgery is not significant, and individual decision-making between these two options should include additional elements representing patients' preference. In conclusion, this model emphasizes the usefulness of decision analysis as a decision aid to medical problem-solving. The Markov simulation, which represents in a realistic manner the natural history of aortic aneurysm, and sensitivity analyses reinforce the credibility of this approach.