The objective of this study is to compare the performance between Viabahn balloon-expandable stents (VBX) and self-expandable covered stents (SES) (Viabahn and Fluency) used as bridging stents for directional branches during F-BEVAR of complex aortic aneurysms (CAA).
Patients with thoracoabdominal aortic aneurysms (TAAA)(Type I-IV) or pararenal aortic aneurysms either high risk for open repair or unsuitable for endovascular repair with commercially available devices were prospectively enrolled into a physician-sponsored investigational device exempt trial. Descriptive statistics of the cohort included demographics, risk factors, as well as anatomic and device characteristics. Individual branches were grouped as either VBX or SES and had data analyzed for primary patency, branched-related type I/III endoleaks, branch-instability, branch-related secondary intervention, and branch-related aortic rupture or death. Categorical variables were expressed as total and percentage, and continuous variable as median (interquartile range [IQR]). Kaplan-Meier curves were used to estimate long-term results. Groups were compared with the log-rank test. P-value <0.05 was considered statistically significant.
During the period from July 2012 through June 2019, 263 patients were treated for CAA(TAAA) with F-BEVAR. The devices used were either custom-manufactured device (CMD) or off-the-shelf p-branch or t-branch Cook devices. The median age was 71 (IQR 66-79) years old, 70% male and 81% Caucasians. The most common cardiac risk factors were smoking (92%), hypertension (91%), hyperlipidemia (78%) and COPD (52%). The total number of vessels incorporated into the repair was 977, with branches representing 18.4% (179 branches). Among these 179 branches, celiac artery(CA), superior mesenteric(SMA), right renal(RRA) and left renal(LRA), received 54(30%), 56(31%), 38(21%) and 31(18%) branches respectively. VBX and SES groups represented 96(54%) and 81(46%) of the branches implanted. The CA, SMA , RRA and LRA received VBX as bridging stents in 40%, 46.7%, 33.8% and 32.2% respectively. The overall cohort survival rate at was 78.5% at 24 months. There was no branch-related rupture or mortality. Primary patency at 24 months (VBX 98.1%, SES 98.6%, log-rank=0.95), freedom from endoleak (VBX: 95.6%, SES: 98.6%, log-rank: 0.66), freedom from secondary intervention (VBX: 94.7%, SES 98.1%, log-rank: 0.33) and freedom from branch-instability (VBX: 95.6%, SES: 97.2%, log-rank: 0.77) were all similar between groups.
This initial experience with VBX stents demonstrated excellent primary patency and similarly low rates of branches-related complications and endoleaks with no branch-related aortic rupture or death. Our results demonstrate that, in a high volume, experienced aortic center, the VBX stent is a safe and effective bridging stent option during the branched endovascular aortic repair. Multicenter studies with a larger cohort and longer follow-up are necessary to validate these findings.

Copyright © 2020. Published by Elsevier Inc.