Risk Factors Analysis Of Aortic Dilatation After Endovascular Treatment Of Debakey â…¢b Aortic Dissection

Objective:The purpose of this study was to investigate the risk factors of aortic dilatation after thoracic endovascular aortic repair (TEVAR) of Debakey Ⅲb aortic dissection (Ⅲb-AD).Methods:Between August 2005 and August 2014, we retrospectively analyzed 112 patients who underwent TEVAR for Ⅲb-AD from two large referral centers (Zhongda Hospital and The First Affiliated Hospital of Dalian Medical University, China). Regular outpatients visits with CT angiography (CTA) were required within 2 weeks, at 3 months,6 months and then annually after the procedure. The main outcome measures were demographics, clinical features, procedural details, postoperative imaging characteristics, decending thoracic and abdominal (divided by the celiac axis) aortic dilatation after TEVAR during follow-up. The latter was defined as a>5mm increase in the maximal saortic diameter at a follow-up CTA compared with the preoperative measurement at each corresponding aortic segment, respectively. Stepwise Cox regression analysis was performed to study independent risk factors of postoperative decending thoracic and abdominal aortic dilatation, respectively.Results:Through an average CTA follow-up of 30.42±20.02 months, among these 112 postoperative patients (mean age,53.99±11.52; range,28-78; 95 male),37 (33.0%) developed decending thoracic aortic dilatation, and 19 (17.0%) were located at the abdominal aorta. Univariate analysis showed that, number of residual intimal tears (P<0.001; P=0.039), cumulative size of residual intimal tears (P<0.001; P=0.001) and incomplete false lumen (FL) thrombosis (P=0.002; P=0.045) at decending thoracic and abdominal aorta, number of visceral branches arising from FL (P=0.003), distal stent graft-induced new entry (dSINE) (P=0.049), and type la endoleak (P<0.001) were associated with decending thoracic aortic dilatation; while maximal FL diameter (P=0.002), number of residual intimal tears (P=0.003) and cumulative size of residual intimal tears (P<0.001) at abdominal aorta, percent dissection length (P=0.029), and type la endoleak (P=0.008) were related to abdominal aortic dilatation. Further analysis with a Cox proportional hazards model displayed that, cumulative size of residual intimal tears at decending thoracic aorta (hazard ratio [HR],1.297; 95% confidence interval [95% CI],1.189-1.414; P<0.001), dSINE (HR,7.097; 95% CI,2.616-19.250; P<0.001), and type Ia endoleak (HR,11.879; 95% CI,5.027-28.068; P<0.001) were the independent risk factors of decending thoracic aortic dilatation after TEVAR; however, cumulative size of residual intimal tears at abdominal aorta (HR,1.122; 95% CI,1.053-1.196; P=0.001) was the unique independent risk factor of abdominal aortic dilatation postoperatively.Conclusion:Cumulative size of residual intimal tears at decending thoracic aorta, dSINE, and type la endoleak were the independent risk factors of decending thoracic aortic dilatation after TEVAR of Ⅲb-AD; while cumulative size of residual intimal tears at abdominal aorta was the unique independent risk factor of postoperative abdominal aortic dilatation.