Background: Optimal management for patients who present acutely with uncomplicated type III dissections of the descending thoracic aorta remains controversial. Patients with dissecting aneurysms represent a subgroup at high risk of rupture who may benefit from early elective surgery as an alternative to standard medical therapy. METHODS. The authors constructed a Markov decision model to compare the following clinical strategies: 1) early elective surgery immediately after diagnosis (EARLY SURGERY), 2) medical therapy with periodic computed tomography and with elective surgery when aortic diameter is projected to reach 6 cm (CT FOLLOW-UP), and 3) medical therapy with urgent surgery for dissection-related complications (WATCHFUL WAITING). Data sources included Medline (1966-1995) and a case series of patients with type III dissecting aneurysms who received medical therapy with radiographic follow-up.
Results: For a typical 60-year-old patient with an acute, uncomplicated 5-cm dissecting aneurysm of the descending thoracic aorta and an operative 30-day mortality rate of 14% for EARLY SURGERY, the model predicts that EARLY SURGERY improves survival compared with CT FOLLOW-UP (9.91 vs 9.44 QALYs). Conservative management may be preferred for patients who have maximum aneurysm diameters < or = 4 cm, are elderly (> or = 75 years), or have higher-than-expected risk of operative mortality.
Conclusions: The choice between early surgery and medical therapy for uncomplicated dissecting aneurysm of the descending thoracic aorta should be tailored to the individual patient's operative risk, risk of dissection-related events, and age. Early surgery may be a reasonable alternative to medical therapy for carefully selected patients at centers with favorable perioperative mortality rates.