Impact of Endoluminal Flow Diverter Number on Aneurysm Treatment Outcomes: A Multicenter Study

The purpose of this study is to evaluate the impact multiple overlapping flow-diverting stents have on aneurysm occlusion rates and iatrogenic complications relative to single flow-diverting stents.

A retrospective review of a multicenter aneurysm database from 2012 to 2020 was performed to identify saccular aneurysms treated initially with single and multiple flow-diverting stents with ≥12-month angiographic and clinical follow-up. Aneurysm occlusion rates as a function of stent number served as a primary outcome measure with iatrogenic complications serving as a secondary outcome measure.

A total of 250 patients were initially treated with a single Pipeline embolization device (PED), and 48 patients were initially treated with multiple PEDs. There was no significant difference in aneurysm size, morphology, or dual-antiplatelet therapy regimen used between groups. There was no significant difference in the aneurysm occlusion (single, 83.6%, versus multiple, 83.4%; P=0.65) or retreatment rates (single, 8.0%, versus multiple, 10.4%; P=0.58) between groups. There was no significant difference in the number of procedure-related complications between groups (single, 8.0%, versus multiple, 4.2%; P=0.42), with 0.8% of patients treated with a single PED and 2.1% of patients treated with multiple PEDs experiencing a procedure-related ischemic stroke.

There is no significant difference in overall aneurysm occlusion rates between aneurysms treated initially with single versus multiple overlapping PEDs nor are there significant differences in procedure-related complications. Single PED flow diversion may be preferred whenever possible, with multiple PED constructs reserved for extenuating clinical circumstances as may be encountered with giant aneurysms.