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

BACKGROUND 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. METHODS 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. RESULTS 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. CONCLUSIONS 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.