Outcomes of flow diversion in intracranial aneurysms accompanied by parent artery stenosis

Background The impact of parent artery stenosis on the treatment of intracranial aneurysms by using flow diversion (FD) remains unknown. This multicenter retrospective study aimed to evaluate the clinical and radiological outcomes of patients with intracranial aneurysms accompanied by parent artery stenosis of different etiologies after FD implantation. Methods The study cohort included patients who received FD treatment at four comprehensive centers from March 2013 to June 2024. The etiological factors underlying intracranial arterial stenosis were categorized as intracranial atherosclerosis (ICAS), intracranial arterial dissection (ICAD), and matricidal aneurysms (MA). Results A total of 161 patients with intracranial aneurysms accompanied by parent artery stenosis were ultimately included for in-depth analysis. The procedures were successfully performed in all patients, with a low incidence of periprocedural complications. In the clinical and angiographic follow-up, all patients had a favorable outcome (modified Rankin Scale score 0–2), and the complete occlusion rate of aneurysms was 64.0% at median 8.0 months (IQR 6–13.5 months). A comparative analysis revealed that, in contrast to the ICAD and MA groups, the ICAS group exhibited a significantly higher rate of in-stent restenosis (28% vs 16.7% vs 5.5%, p = 0.020). Conclusions FDs demonstrated satisfactory performance in terms of periprocedural complications, favorable clinical outcomes, and complete occlusion on follow-up imaging in the management of intracranial aneurysms accompanied by parent artery stenosis. Notably, ICAS exerted a substantially greater influence on in-stent restenosis and entailed a higher requirement for repeat angioplasty compared with ICAD and MA.