Is surgery always mandatory for type A aortic dissection?

BACKGROUND: The International Registry of Aortic Dissections showed that 42% of the unoperated patients with type A acute aortic dissection were discharged from the hospital after intensive medical treatment. We analyzed our experience to identify a preoperative score for in-hospital mortality to propose an alternative strategy for type A acute aortic dissection. METHODS: From 1980 to 2004, 616 consecutive patients with type A acute aortic dissection underwent surgery in our center. The preoperative univariate risk factors with a probability value less than 0.05 were entered into multivariate analysis. A risk equation was developed: predicted mortality = exp(beta 0 + sigma beta i X i)/[1 + exp(beta 0 + sigma beta i X i)]. RESULTS: Early mortality was 25.1% (154 of 616 patients). Five risk factors were identified: age, coma, acute renal failure, shock, and redo operation. The beta i values are age 0.023, shock 0.771, reoperation 0.595, coma 1.162, acute renal failure 0.778; the constant (beta 0) is -2.986. CONCLUSIONS: Our large, single-center experience allowed us to develop a mathematical model to predict 30-day mortality for type A acute aortic dissection. When the expected mortality is 58% or less, surgery is always indicated. When the predicted mortality is greater than 58%, the possibility of survival is similar, according to International Registry of Aortic Dissections data, for surgery and medical treatment. In such cases surgery can no longer be considered mandatory, and a careful evaluation of the individual patient is recommended to choose the more suitable strategy.