Computed Tomography-Based Study Exploring the Feasibility of Endovascular Treatment of Type A Aortic Dissection in the Chinese Population

Abstract

PURPOSE: To characterize type A aortic dissection (TAAD) in the Chinese population using high-resolution computed tomography (CT) and explore potential candidacy for endovascular repair of TAAD. METHODS: The imaging studies and medical records of all 302 patients presenting with TAAD at two Chinese hospitals from 2010 to 2013 were reviewed. Of these, 221 patients were excluded because of missing/inadequate preoperative CT scans. The remaining 91 patients (64 men; mean age 51.1±7.5 years) had CT data adequate to assess anatomical suitability for endovascular treatment. Entry tears were identified using multiplanar reconstructions, while morphological measurements were based on a centerline of flow (CLF) technique. Suitability for endovascular treatment was based on a proximal landing zone ≥20 mm long, a true lumen aortic diameter ≤38 mm, and a total aortic diameter ≤46 mm; no coronary bypass grafts originating from the ascending aorta; no malfunctioning aortic valve; and good cerebral and cardiac perfusion. RESULTS: In the 91 patients, the precise location of the primary proximal entry tear could be identified in only 34 (37.4%) patients; in these patients, the identifiable intimal tears were located 36.4±41.0 mm distal to the closest coronary artery. The CLF was successfully generated in the CT scans of all patients; the mean lumen and total aortic lumen diameters at the entry tear level were 37.6±6.3 and 44.3±13.3 mm, respectively. Based on the CT measurements, stent-graft repair would have been anatomically feasible in 35 (38.5%) patients. No proximal landing zone (n=23), large aortic diameter (n=15), abnormal aortic valve (n=10), previous coronary bypass graft surgery (n=5), and poor cerebral and cardiac perfusion (n=3) were obstacles that affected the suitability for this treatment. CONCLUSION: Based on high-resolution CT scans, our pilot study suggested that 38% of Chinese patients with TAAD could potentially be treated by stent-grafting based on the anatomical characteristics of the proximal dissection.