Ruptured posterior inferior cerebellar artery aneurysm in a neonate treated with coil embolization: A technical report.

Background: Intracranial saccular aneurysms in the neonatal population are exceedingly rare, with fewer than 50 cases in the literature, the majority of which are localized to the anterior circulation. Rarer still is endovascular treatment, occurring in only seven of these cases, with almost all interventions involving the sacrifice of the parent artery. Case Description: A 1-month-old term male presented lethargic and irritable with bulging fontanelles and no neurologic deficit. Transfontanelle ultrasonography showed intraventricular hemorrhage and hydrocephalus. Non-invasive angiography revealed subacute subarachnoid hemorrhage with hemosiderosis and multiple cystic septations suggestive of repeated hemorrhage from a distal right posterior inferior cerebellar artery (PICA) aneurysm. Digital subtraction angiography identified a right 8 mm × 5 mm telovelotonsillar segment aneurysm, subsequently coiled to occlusion without parent artery sacrifice. Cerebrospinal fluid diversion through an external ventricular drain, followed by ventriculoperitoneal shunt placement, was required. No evidence of cerebral vasospasm or delayed cerebral ischemia occurred in the postoperative period. Conclusion: Ruptured cerebral aneurysms in neonates remain exceptionally rare. We present the largest, coiled PICA neonatal aneurysm in the literature, and only the second neonatal aneurysm of any location endovascularly treated without parent artery sacrifice. Despite the inherent challenges of neonatal vascular access, endovascular treatment without parent artery occlusion can be considered when aneurysm morphology is favorable.