Surgical treatment for acute aortic arch dissection.

Between March 1983 and December 1993, 24 consecutive patients with acute aortic dissection resulting from a tear located in the aortic arch or at the base of the innominate artery underwent surgical treatment. Before 1988, 11 patients (group 1) underwent either isolated ascending aorta replacement (eight cases) or composite graft replacement (three) by the conventional method. In this group, the hospital mortality rate was 36.4%; two of seven surviving patients required reoperation for aortic arch. After 1989, 13 patients (group 2) underwent either hemiarch replacement (five cases), total arch replacement (three), extended ascending aortic replacement or composite graft replacement with hemiarch replacement (one) under a brief period of circulatory arrest (mean 33.3 min) at a mean(range) rectal temperature of 20.8(18-23) degrees C by open distal anastomosis. The operative mortality rate in group 2 was 15.4%. Ten of 13 surviving patients are free from reoperation (mean follow-up 40 months). In most patients with acute type A dissection in which the tear is located at the proximal aortic arch or at the base of the innominate artery, the use of an open technique during a brief period of hypothermic circulatory arrest is advocated to: (1) perform a more secure distal anastomosis; (2) provide a more accurate assessment and resection of intimal disruption; and (3) avoid further aortic injury from the cross-clamp.