Outcomes of chimney and fenestrated endografting using Viabahn VBX and atrium iCAST stents.

Background: The Atrium iCAST balloon expandable stent is the traditional choice of stent for chimney and fenestrated endovascular aneurysm repair (ChEVAR and FEVAR respectively). Due to the iCAST's lack of flexibility, the Gore Viabahn balloon-expandable stent (VBX; W. L. Gore & Associates, Inc., Newark, DE, USA) has arisen as a flexible alternative for parallel or branch graft placement during complex EVAR. Our purpose was to analyze patients' outcomes after undergoing ChEVAR or FEVAR using VBX or iCAST stents with the major outcome of assessing stent graft patency. The secondary outcome was residual aneurysm sac behavior.

Methods: We retrospectively reviewed patients who were treated by ChEVAR or FEVAR with placement of iCAST or VBX stents from July 2012 to August 2018. Patients received follow-up CT scan and/or aortic duplex imaging.

Results: We examined 53 cases (70% ChEVAR and 30% FEVAR) with 15.6 months (0-76.5 months) mean follow-up period. Placement of stents included renal (65 iCAST and 38 VBX), superior mesenteric (12 iCAST and 13 VBX), celiac (4 iCAST and 5 VBX), and iliac arteries (1 iCAST and 5 VBX). A total of 143 stents (57% iCAST and 43% VBX) were successfully deployed with 100% initial patency. Follow-up patency was similar for both stent types (100% VBX vs 98.7% iCAST). VBX and iCAST had the same follow-up Type 1a endoleak occurrence (9%). Average aneurysm sac sizes for iCAST decreased more than VBX (9% iCAST and 4% VBX, P=0.21), however, the iCAST group had longer follow-up.

Conclusions: Our experience demonstrates that the use of VBX stents for ChEVAR and FEVAR is a safe and effective alternative to iCAST stents with excellent mid-term patency without a negative impact on endoleak frequency.