Is preservation of the aortic valve different between acute and chronic type A aortic dissections?

Objectives: In repair of acute type A aortic dissection, the type of proxim al repair of the ascending aorta has been of great interest; however, very few reports are available regarding this issue in chronic aortic dissection . The surgical strategies for proximal repair in chronic dissection may not the same as those for acute dissection. We reviewed our 10-year experience of both acute and chronic type A aortic dissections in order to elucidate the validity of valve preservation and the long-term results of aortic regu rgitation (AR). Methods: From 1990 to 1999, 93 patients (55 acute and 38 ch ronic dissections) underwent operation for type A aortic dissection. Five M artan patients were included in each group. The degree of AR was evaluated by echocardiography before and after (at hospital discharge and late follow -up) operation. Results: In acute type A aortic dissection (n = 55), 16 pat ients had AR grade II or greater (29%), of whom seven had AR grade III (13% ). In 29 patients, dissection was found below the sinotubular junction (STJ ) and 14 patients had AR grade II or greater (48%). The aortic valve was re placed in four patients (7%), of whom three had Marfan's syndrome. Only one non-Marfan patient required aortic valve replacement because of valve sten osis. In those whose aortic valve was preserved (n = 51), three patients st ill had AR grade II at hospital discharge, while at late follow-up, AR had deteriorated to grade III in two of them, although no reoperation. has been required so far. In chronic type A aortic dissection (n = 38), 14 patients had AR grade It or greater (37%), of whom 11 had AR grade III or greater ( 29% vs. 13% in acute dissection; P = 0.051). In 15 patients, dissection was found below the STJ and 12 patients had AR grade II or greater (80% vs. 48 % in acute dissection; P = 0.043). The aortic valve was replaced in eight p atients (21% vs. 7% in acute dissection; P = 0.051), including three Marfan patients. Of those whose aortic valve was preserved (n = 30), two patients required reoperation for severe AR. The freedom from postoperative AR grad e III or greater was 89% at 5 years for operative survivors with acute diss ection and 92% for those with chronic dissection, respectively. Conclusions : This retrospective study suggests that preservation of the aortic valve i n acute type A aortic dissection is feasible in non-Marfan patients regardl ess of the degree of AR. In chronic dissection, aortic root replacement nee ds to be considered when the degree of AR is greater than moderate because of a dilated STJ and/or annulus. In both acute and chronic dissections, sat isfactory mid- to long-term results with a low incidence of reoperation wer e obtained in those whose aortic valve was preserved. (C) 2001 Elsevier Sci ence B.V. All rights reserved.