Clinical significance of a false lumen pathway through the arch in acute type A aortic dissection and its influence on cervical branch compromise.

OBJECTIVES Upon onset of acute type A aortic dissection, the aortic true lumen generally becomes fixed around the supra-aortic branches in the greater curvature and Botallo's ligament in the lesser curvature of the aortic arch. Therefore, the pathways of the false lumen through the arch can be categorized as anterior, bilateral and posterior. We investigated the relationship between a false lumen pathway through the arch and cervical branch compromise, stratified by primary tear location. METHODS Sixty-four consecutive patients with acute type A aortic dissection underwent emergency surgery at our institution between March 2005 and October 2013. Of these, 40 cases (63%) were DeBakey type I, 15 cases (23%) were type II and 9 cases (14%) were type III-D (retrograde type A). We conducted a retrospective review of preoperative computed tomographic angiography using three-dimensional image post-processing tools for 43 cases, excluding 15 cases with type II and 6 cases with type I for which preoperative digital image data were not available. RESULTS Of the 43 cases, 14, 18 and 11 revealed anterior, bilateral and posterior pathways, respectively. Twenty-one cases (49%) showed a primary intimal tear in the ascending aorta (8 anterior, 12 bilateral and 1 posterior), 12 cases (28%) showed a primary intimal tear in the aortic arch (5 anterior, 3 bilateral and 4 posterior) and 10 cases (23%) showed a primary intimal tear in the descending aorta (1 anterior, 3 bilateral and 6 posterior). Twelve of the 14 anterior pathway cases (86%) had a total of 26 supra-aortic branch compromises, 13 of the 18 bilateral pathway cases (72%) had a total of 20 supra-aortic branch compromises, while only 4 of the 11 posterior pathway cases (36%) had a total of four supra-aortic branch compromises. None of the 11 posterior pathway cases had a dissection extending into all 3 supra-aortic branches. CONCLUSIONS Posterior pathway cases generally showed primary tear locations in the arch or descending aorta, and cervical branch compromise was rare. Aortic dissections tended to extend into the cervical branches through the anterior side of the aortic arch. A false lumen pathway through the arch was strongly associated with cervical branch compromise in acute type A aortic dissections.