A middle-aged patient presented with subarachnoid hemorrhage and was found to have a ruptured superior cerebellar artery (SCA) aneurysm arising from the origin of a rare anastomotic branch between the right SCA and right posterior cerebral artery (PCA). The aneurysm was secured by transradial coil embolization, and the patient made a good functional recovery. This case demonstrates an aneurysm arising from an anastomotic branch between the SCA and PCA, which may represent a remnant of a persistent primordial hindbrain channel. Although variations in basilar artery branches are common, aneurysms rarely can form at the site of seldom- seen anastomoses between the branches of the posterior circulation. The complex embryology of these vessels, which includes anastomoses and the involution of primitive arteries, may have contributed to the development of this aneurysm arising from an SCA-PCA anastomotic branch.

PURPOSE: The Pipeline embolization device (PED) is approved in the USA for treating giant and large aneurysms arising from the petrous to superior hypophyseal segments of the internal carotid artery in patients older than 21 years of age. This study investigates off-label PED results in a large cohort. MATERIALS AND METHODS: Retrospective, single-center review of all patients who had off-label PED surgery. RESULTS: Sixty-two aneurysms (48 patients) underwent off-label PED treatment from 2012–2017. There were 44 females and four males (age 21 to 75 years; mean/median, 54.3/55.0 years). The most common presenting symptom was headache (47/62, 75.8%). All aneurysms were in the anterior circulation. Aneurysm size ranged from 1.4 to 25.0 mm (mean/median, 7.6/6.9 mm). Fifty-two aneurysms had post-operative imaging with total/near-complete occlusion of 84.6% (44/52). Aneurysm-based operative near-term complication rate was 9.7% while there were no permanent complications. For aneurysms and headache, 86.7% improved/resolved after embo-surgery, and were four times more likely to have a better clinical outcome (resolved or improved symptoms) after surgery (odds ratio [OR], 4.333; P=0.0325). Left-sided aneurysms had a higher occlusion rate (OR, 20; P=0.0073). Hypertension (OR, 4.2; P=0.0332) and smoking (OR, 7; P=0.0155) were more prone towards aneurysm occlusion. Patients without a family history were 14 times more likely to have favorable imaging outcome (P=0.0405). There is no difference of occlusion rates between untreated and previously treated aneurysms (P=0.6894). Overall, occlusion rate decreased by 14% with an increase of aneurysm size by 1 mm (P=0.0283). CONCLUSION: For anterior circulation aneurysms, the off-label application of PED is as effective and safe as reported for on-label intracranial aneurysms.
Aneurysm ; Carotid Artery, Internal ; Cohort Studies ; Female ; Headache ; Humans ; Hypertension ; Intracranial Aneurysm ; Male ; Retrospective Studies ; Smoke ; Smoking