Branch Vessel Patency after Thoracic Endovascular Aortic Repair for Type B Aortic Dissection

Background: Thoracic endovascular aortic repair (TEVAR) for type B aortic dissections is used to promote false lumen (FL) thrombosis and favorable aortic remodeling, but its impact on occlusion of FL origin branch vessels has not been widely described. We compare FL versus true lumen (TL) branch vessel patency after TEVAR. Methods: Patients treated by TEVAR for type B aortic dissection in zones 2-5 in the Vascular Quality Initiative from 2009 to 2018 were evaluated. The primary outcome was postoperative branch patency. Secondary outcomes were need for branch vessel intervention, preoperative origin, and postoperative patency of individual branch vessels (celiac, superior mesenteric artery, renal arteries, and iliac arteries). A subset analysis was performed comparing acute and chronic dissections. Results: Of 11,774 patients, 1,484 met criteria for analysis. The left renal was the most common to have FL origin (21.6%), whereas right and left common iliac arteries were the most likely to originate off both lumens (BLs; 22% and 24%). Branch vessels that originated from the TL, FL, BLs, or were obstructed had postoperative patency rates of 99%, 99%, 99%, and 87% (P < 0.0001). Branch vessel treatment was performed in 5% of patients. The right (2.5%) and left (2.8%) renal arteries were the most frequently obstructed branches postoperatively. On multivariate analysis, preoperatively obstructed branches (odds ratio 0.03, P < 0.0001) were negatively associated with postoperative branch patency and branch vessel treatment (odds ratio 3.8, P = 0.004) was positively associated with postoperative patency. FL or BL origin, number of zones covered by TEVAR, urgency, dissection chronicity (acute versus chronic), and demo-graphics were not independently associated with patency. These findings remained unchanged in the subset analysis of only acute dissections. Conclusions: Branch vessel patency rates after TEVAR for a type B aortic dissection are high and are not significantly different for FL or BL origin vessels compared with TL vessels. Branches that are patent before TEVAR almost always remain patent after TEVAR, but branch vessel stenting may be required in less than 5%.