Fenestrated endovascular aneurysm repair (FEVAR) is a well-established, effective technique for complex abdominal and thoracoabdominal aneurysm repair. Among various bridging stents, Atrium iCast (Maquet, Rastatt, Germany) covered stents have been adopted by many as the device of choice, with excellent outcomes. Recently, Gore Viabahn VBX stents (W. L. Gore & Associates, Flagstaff, Ariz) became commercially available in the United States. The aim of our study was to compare our experience with VBX and iCast as bridging stents during FEVAR. A retrospective review was performed of FEVARs for complex abdominal and thoracoabdominal aneurysms at a single institution from 2015 to 2018. All patients were at high risk for open repairs. Custom-manufactured or physician-modified devices were implanted. Bridging stents across reinforced fenestrations were included in the study. VBX and iCast stents were compared for technical success, branch patency, branch-related endoleak, and reinterventions. There were 75 patients who underwent FEVAR during the study period; 10 patients had juxtarenal, 23 had pararenal, and 41 had thoracoabdominal aortic aneurysms, and 1 had a pseudoaneurysm. Twenty-four patients were symptomatic, and three patients presented with rupture. A total of 197 branch vessels were targeted with fenestrations. Of 197 targeted branch vessels, 193 (34 celiac, 55 superior mesenteric artery [SMA], 104 renals) were bridged successfully (98%). Four target vessels (three renals and one dominant intercostal) could not be bridged because of severe aortic tortuosity causing fenestration misalignment. A total of 87 vessels were incorporated with iCast and 106 vessels with VBX. The mean follow-up was 5.5 months (6.7 months for iCast and 3.8 months for VBX). Secondary relining stents were used in 14 (16.1%) iCast branches (1 celiac, 3 SMA, and 10 renals) and 8 (7.5%) VBX stents (4 SMA, and 4 renals; P = .072). The 6-month branch patency for iCast was 96.2%, with one celiac and one renal in-stent stenosis; the 6-month patency for VBX was 97.4%, with one celiac branch occlusion (P = .661). At 6 months, there were no branch-related endoleaks for iCast, whereas six VBX branch (5.7%) vessels had type IC endoleak due to branch stent undersizing (P = .033). There were no type III endoleaks across the fenestration seal in either group. Overall short-term branch-related reintervention rate was 0% for iCast and 2.8% (3/106) for VBX (P = .253). One celiac and two SMA endoleaks were intervened on in the VBX group. Gore Viabahn VBX and Atrium iCast show high short-term patency and low endoleak rates as bridging stents during fenestrated endovascular repair of complex abdominal and thoracoabdominal aneurysms. Longer follow-up is needed to assess late device-related complications.