Flow Diversion for the Treatment of MCA Bifurcation Aneurysms—A Single Centre Experience

Flow diverters are important tools in the treatment of intracranial aneurysms. However, their impact on aneurysmal occlusion rates, morbidity, mortality, and complication rates is not fully examined. We conducted a systematic review of the literature searching multiple databases for reports on the treatment of intracranial aneurysms with flow-diverter devices. Random effects meta-analysis was used to pool outcomes of aneurysmal occlusion rates at 6 months, and procedure-related morbidity, mortality, and complications across studies. A total of 29 studies were included in this analysis, including 1451 patients with 1654 aneurysms. Aneurysmal complete occlusion rate was 76% (95% confidence interval [CI], 70%-81%). Procedure-related morbidity and mortality were 5% (95% CI, 4%-7%) and 4% (95% CI, 3%-6%), respectively. The rate of postoperative subarachnoid hemorrhage was 3% (95% CI, 2%-4%). Intraparenchymal hemorrhage rate was 3% (95% CI, 2%-4%). Perforator infarction rate was 3% (95% CI, 1%-5%), with significantly lower odds of perforator infarction among patients with anterior circulation aneurysms compared with those with posterior circulation aneurysms (odds ratio, 0.01; 95% CI, 0.00-0.08; P<0.0001). Ischemic stroke rate was 6% (95% CI, 4%-9%), with significantly lower odds of perforator infarction among patients with anterior circulation aneurysms compared with those with posterior circulation aneurysms (odds ratio, 0.15; 95% CI, 0.08-0.27; P<0.0001). This meta-analysis suggests that treatment of intracranial aneurysms with flow-diverter devices is feasible and effective with high complete occlusion rates. However, the risk of procedure-related morbidity and mortality is not negligible. Patients with posterior circulation aneurysms are at higher risk of ischemic stroke, particularly perforator infarction. These findings should be considered when considering the best therapeutic option for intracranial aneurysms.

Endoluminal reconstruction with flow diverting devices represents a novel constructive technique for the treatment of cerebral aneurysms. We present the results of the first prospective multicenter trial of a flow-diverting construct for the treatment of intracranial aneurysms. Patients with unruptured aneurysms that were wide-necked (> 4 mm), had unfavorable dome/neck ratios (<1.5), or had failed previous therapy were enrolled in the PITA trial between January and May 2007 at 4 (3 European and 1 South American) centers. Aneurysms were treated with the PED with or without adjunctive coil embolization. All patients underwent clinical evaluation at 30 and 180 days and conventional angiography 180 days after treatment. Angiographic results were adjudicated by an experienced neuroradiologist at a nonparticipating site. Thirty-one patients with 31 intracranial aneurysms (6 men; 42-76 years of age; average age, 54.6 years) were treated during the study period. Twenty-eight aneurysms arose from the ICA (5 cavernous, 15 parophthalmic, 4 superior hypophyseal, and 4 posterior communicating segments), 1 from the MCA, 1 from the vertebral artery, and 1 from the vertebrobasilar junction. Mean aneurysm size was 11.5 mm, and mean neck size was 5.8 mm. Twelve (38.7%) aneurysms had failed (or recurred after) a previous endovascular treatment. PED placement was technically successful in 30 of 31 patients (96.8%). Most aneurysms were treated with either 1 (n = 18) or 2 (n = 11) PEDs. Fifteen aneurysms (48.4%) were treated with a PED alone, while 16 were treated with both PED and embolization coils. Two patients experienced major periprocedural stroke. Follow-up angiography demonstrated complete aneurysm occlusion in 28 (93.3%) of the 30 patients who underwent angiographic follow-up. No significant in-construct stenosis (≥ 50%) was identified at follow-up angiography. Intracranial aneurysm treatment with the PED is technically feasible and can be achieved with a safety profile analogous to that reported for stent-supported coil embolization. PED treatment elicited a very high rate (93%) of complete angiographic occlusion at 6 months in a population of the most challenging anatomic subtypes of cerebral aneurysms.