A Case of Acute Type B Aortic Dissection Subsequent to Asymptomatic Chronic Type A Aortic Dissection Which Was Difficult to Distinguish from Acute Type A Aortic Dissection

Abstract

Aortic dissection presents with acute chest or back pain. However, it can be asymptomatic in the acute phase with delayed symptomatic presentation or incidental diagnosis upon chest imaging. We report a case of acute type B aortic dissection subsequent to chronic type A aortic dissection which was difficult to distinguish from acute type A aortic dissection. A 45-year-old man was admitted to a hospital with sudden back pain. An enhanced chest CT revealed a suspected acute type A aortic dissection. The patient was transferred to our hospital and we performed an emergent total arch replacement. Intraoperative findings showed that there were two entries at the origin of the brachiocephalic artery and the left subclavian artery. The ascending aorta presented wall thickening but the descending aorta did not present wall thickening. Histopathologically, the adventitia was obviously thickened with dissection findings in the tunica media. Thus it was diagnosed as acute type B aortic dissection subsequent to chronic type A aortic dissection. Great caution should be taken in asymptomatic chronic aortic dissection.