Intracranial Aneurysms: Midterm Outcome of Pipeline Embolization Device—A Prospective Study in 143 Patients with 178 Aneurysms

To evaluate the midterm clinical and angiographic outcomes after pipeline embolization device (PED) placement for treatment of intracranial aneurysms. This prospective nonrandomized multicenter study was approved by the review boards of all involved centers; informed consent was obtained. Patients (143 patients, 178 aneurysms) with unruptured saccular or fusiform aneurysms or recurrent aneurysms after previous treatment were included and observed angiographically for up to 18 months and clinically for up to 3 years. Study endpoints included complete aneurysm occlusion; neurologic complications within 30 days and up to 3 years; clinical outcome of cranial nerve palsy after PED placement; angiographic evidence of occlusion or stenosis of parent artery and that of occlusion of covered side branches at 6, 12, and 18 months; and clinical and computed tomographic evidence of perforator infarction. There were five (3.5%) cases of periprocedural death or major stroke (modified Rankin Scale [mRS] > 3) (95% confidence interval [CI]: 1.3%, 8.4%), including two posttreatment delayed ruptures, two intracerebral hemorrhages, and one thromboembolism. Five (3.5%) patients had minor neurologic complications within 30 days (mRS = 1) (95% CI: 1.3%, 8.4%), including transient ischemic attack (n = 2), small cerebral infarction (n = 2), and cranial nerve palsy (n = 1). Beyond 30 days, there was one fatal intracerebral hemorrhage and one transient ischemic attack. Ten of 13 patients (95% CI: 46%, 93.8%) completely recovered from symptoms of cranial nerve palsy within a median of 3.5 months. Angiographic results at 18 months revealed a complete aneurysm occlusion rate of 84% (49 of 58; 95% CI: 72.1%, 92.2%), with no cases of parent artery occlusion, parent artery stenosis (