Natural history of the false channel of type A aortic dissection after surgical repair: CT study.

To evaluate the false channel after surgical repair of a type A aortic dissection, postoperative computed tomographic (CT) scans were retrospectively reviewed in 33 patients. Initial CT demonstrated persistence of a double channel distal to the site of surgical repair in 26 patients (79%). In four of these patients serial CT demonstrated enlargement of the false channel, a finding that contributed to the decision to repeat surgery. Progression of thrombus was noted in five patients. Peripheral calcification within the aortic wall of the false channel, presumably located on the "pseudointima," was found in six patients. Because of the progressive nature of type A dissections in the postoperative period, serial CT examinations can provide important information on patients who have undergone surgical correction of a type A dissection.