Comparison Of Self- and Balloon-Expandable Bridging Stent-Grafts in Branched Endovascular Aortic Repair (COVIBRI study)

Endovascular treatment of thoracoabdominal aortic aneurysms has become common, with satisfactory results. Nevertheless, long-term durability remains an issue mainly because of target visceral vessel (TVV) instability. Currently, no covered stent has been approved as a bridging stent-graft, demanding continuous research on this topic. This was a multicenter observational retrospective cohort study comparing mid-term results of the Bard Covera Plus and Gore VBX as bridging stent-grafts (BSGs) during branched endovascular aneurysm repair (BEVAR). The primary outcome was the comparison of the target vessel instability between the two groups. Primary patency, freedom from branch-related type I/III endoleaks and reintervention, and technical and clinical success were considered secondary outcomes. Logistic regression analysis was used to assess the association between selected baseline factors and TVV instability. TVV instability during follow-up was then evaluated using the Kaplan-Meier cumulative function. Three-hundred-forty-five TVVs in 106 patients were considered suitable for the analysis. Two-hundred-twenty vessels were stented with the Covera stent-graft (64%) and 125 with VBX (36%). Two-hundred-ninety-nine TVVs received a single bridging stent-graft (BSG), 45 two BSGs, and only 1 three BSGs. Bare metal stent relining was required in 36% of TVVs, mostly in the Covera group (89 (41%) vs. 36 (29%); P .030). The primary technical success rate was 96% (331/345), and the assisted primary technical success rate was 99% (342/345). The TVV instability rate within 30 days was 2% (1 Covera and 5 VBX; P .015). Three BSG occlusions (one Covera and two VBX) and three type 1c endoleaks (three VBX) were detected. Median follow-up was 13.9 months (range 5.8-25.5 months). Sixteen TVVs instabilities were detected during the follow-up. Twelve BSG occlusions (6 Covera and 6 VBX), 3 type Ic endoleaks (1 Covera and 2 VBX), and 1 type IIIc endoleak (VBX). The overall target vessel instability rate was 5% (16/342). TVV instability was associated with the use of Gore VBX in the univariable logistic regression (OR 3.0, 95%CI 1.1-8.0, P .027). Aneurysm rupture and aneurysm diameter were also associated with TVV instability in the univariable analysis (P .002 and P .008, respectively). The only factor predisposing to TVV instability in the multivariable logistic regression analysis was the use of Gore VBX as a BSG (OR 2.9, 95%CI 1.0-8.0, P .043). Kaplan-Meier analysis showed a sign