Update on flow diverters for the endovascular management of cerebral aneurysms

To evaluate the safety and effectiveness of the Pipeline Embolization Device (PED; ev3/Covidien, Irvine, Calif) in the treatment of complex intracranial aneurysms. The Pipeline for Uncoilable or Failed Aneurysms is a multicenter, prospective, interventional, single-arm trial of PED for the treatment of uncoilable or failed aneurysms of the internal carotid artery. Institutional review board approval of the HIPAA-compliant study protocol was obtained from each center. After providing informed consent, 108 patients with recently unruptured large and giant wide-necked aneurysms were enrolled in the study. The primary effectiveness endpoint was angiographic evaluation that demonstrated complete aneurysm occlusion and absence of major stenosis at 180 days. The primary safety endpoint was occurrence of major ipsilateral stroke or neurologic death at 180 days. PED placement was technically successful in 107 of 108 patients (99.1%). Mean aneurysm size was 18.2 mm; 22 aneurysms (20.4%) were giant (>25 mm). Of the 106 aneurysms, 78 met the study's primary effectiveness endpoint (73.6%; 95% posterior probability interval: 64.4%-81.0%). Six of the 107 patients in the safety cohort experienced a major ipsilateral stroke or neurologic death (5.6%; 95% posterior probability interval: 2.6%-11.7%). PED offers a reasonably safe and effective treatment of large or giant intracranial internal carotid artery aneurysms, demonstrated by high rates of complete aneurysm occlusion and low rates of adverse neurologic events; even in aneurysms failing previous alternative treatments.

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.

Introduction The purpose of this study was to evaluate the safety and efficacy of the recently available flow diverter “pipeline embolization device” (PED) for the treatment of intracranial aneurysms and dissections. Methods Eighty-eight consecutive patients underwent an endovascular treatment of 101 intracranial aneurysms or dissections using the PED between September 2009 and January 2011. The targeted vessels include 79 (78%) in the anterior circulation and 22 (22%) in the posterior circulation. We treated 96 aneurysms and 5 vessel dissections. Multiple devices were implanted in 67 lesions (66%). Results One technical failure of the procedure was encountered. Immediate exclusion of the target lesion was not observed. Angiographic follow-up examinations were carried out in 80 patients (91%) with 90 lesions and revealed complete cure of the target lesion(s) in 47 (52%), morphological improvement in 32 lesions (36%), and no improvement in 11 lesions (12%). Six major complications were encountered: one fatal aneurysm rupture, one acute and one delayed PED thrombosis, and three hemorrhages in the dependent brain parenchyma. Conclusion Our experience reveals that the PED procedure is technically straightforward for the treatment of selected wide-necked saccular aneurysms, fusiform aneurysms, remnants of aneurysms, aneurysms with a high likelihood of failure with conventional endovascular techniques, and dissected vessels. While vessel reconstruction, performed after dissection, is achieved within days, remodeling of aneurysmal dilatations may take several months. Dual platelet inhibition is obligatory. Parenchymal bleeding into brain areas dependent on the target vessel is uncommon.