[Midterm and long-term angiographic outcomes and efficacy analysis of the Pipeline Embolization Device in the treatment of intracranial aneurysms].

To investigate the midterm and long-term efficacy of flow-diverter device in treating intracranial aneurysms (IAs) and analyze its clinical outcomes in anterior circulation aneurysms and posterior circulation aneurysms. This is a retrospective case series study. The data of 566 intracranial aneurysm patients (681 aneurysms) treated with the flow-diverter device at Department of Neurosurgery, Beijing Neurosurgical Institute, Beijing Tiantan Hospital, Capital Medical University from January 2018 to January 2021 were retrospectively analyzed. There were 205 males and 361 females, with an age ((IQR)) of 55 (14) years (range:18 to 77 years). Twelve patients (12 aneurysms) had ruptured aneurysms before surgery, and 75 patients (172 aneurysms) had multiple aneurysms. Preoperative modified Rankin scale (mRS) >2 points in 16 patients.There were 444 patients (552 aneurysms) in the anterior circulation group and 122 patients (129 aneurysms) in the posterior circulation group. Postoperative follow-up was conducted via outpatient visits or telephone calls at 3 to 12 months after the procedure. Baseline aneurysm parameters, surgical information, and imaging and clinical outcomes were collected. Univariate and multivariate Logistic regression analyses were used to identify independent factors associated with long-term incomplete aneurysm occlusion. Intraoperative use of flow diverter-assisted coil embolization was performed in 221 patients (226 aneurysms), and balloon assistance was used in 20 patients (22 aneurysms).The intraoperative rupture rate was 0.5% (3/566), and the intraoperative thrombosis rate was 0.7% (4/566). The in-hospital mortality rate was 1.2% (7/566). Postoperative complications included subarachnoid hemorrhage in 5 patients (0.9%), intracerebral hemorrhage in 2 patients (0.4%), ischemic stroke in 19 patients (3.6%), and transient ischemic attack in 16 patients (3.0%). Imaging follow-up was available for 447 patients (548 aneurysms) with a follow-up duration of (16.7±6.7) months (range:3 to 45 months). Incomplete aneurysm occlusion occurred in 79 patients (95 aneurysms), accounting for 17.3% (95/548). Parent artery stenosis was observed in 63 patients (72 aneurysms), accounting for 13.1% (72/548). Clinical follow-up was available for 530 patients (644 aneurysms) with a follow-up duration of (29.4±11.3) months (range:3 to 54 months). One case of mRS score >2 points was observed in 18 patients, accounting for 3.4% (18/530). Among them, the rate of incomplete occlusion in the anterior and posterior circulation group was 16.9% (76/450) and 19.4% (19/98), respectively, and the rate of parent artery stenosis was 10.9% (49/450) and 23.5% (23/98), respectively; the rate of mRS score>2 points was 2.4% (10/415) and 7.0% (8/115), respectively. Univariate and multivariate Logistic regression analysis showed that aneurysm neck size (=0.075,=1.08, =0.028) and coil use (=-1.070, =0.034, =0.001) were independent factors influencing long-term aneurysm occlusion. The flow-diverter device demonstrates good safety and efficacy in the midterm and long-term treatment of overall IAs. However, further research is needed to focus on the midterm and long-term treatment outcomes of aneurysms with relatively wide neck and posterior circulation aneurysms.