Repair of an acute type a dissection: Fate of the remnant false lumen and preserved aortic valve

From January 1992 through March 1997, 75 patients (DeBakey type I/II=56/19) underwent a surgical repair of a type A acute dissection. The patients included 37 men and 38 women ranging in age from 23 to 83 years with a mean of 65 years. All patients were admitted to our hospital with a mean interval of 2.2 days from the episode of onset. The overall hospital mortality rate was 25% (19/75). There were three late deaths among the 56 patients discharged from the hospital. The actuarial survival rate for the patients surviving the operation was 87% at 5 years after repair. A subsequent aortic operation was necessary in 6 patients, while 3 other patients who had late aortic complications were put on medical therapy alone. As a result, the aortic event-free survival rate was 54% at 5 years. For a type I dissection the false lumen was completely thrombosed after repair in 34%. The descending thoracic aorta with a patent false lumen was markedly enlarged in proportion to the follow-up time. After a conservative approach to the aortic valve, all but one patient demonstrated an adequate valve function throughout this study period. This experience with a midterm follow-up showed an acceptable durability of the preserved aortic valve and a progressive enlargement of the persistent false lumen with a high rate of aortic complications. Hence, all patients with a type A dissection need a close follow-up to assess the aorta for complications of either recurrent or residual aneurysms and dissections.