Endosaccular Coil Embolization of Ruptured Anterior Inferior Cerebellar Artery Pseudoaneurysm After Gamma Knife Surgery for Vestibular Schwannoma: A Case Report and Literature Review.

Ruptured pseudoaneurysm of the distal anterior inferior cerebellar artery (AICA) in patients with a history of gamma knife surgery (GKS) for vestibular schwannoma (VS) is rare. Several previous reports have described treatment strategies for radiation-induced pseudoaneurysm in the AICA: either surgical trapping or endovascular parent artery occlusion of the AICA. We present the first case of endosaccular coil embolization for a ruptured pseudoaneurysm in a large-diameter AICA after GKS for VS, successfully preserving the parent AICA. Major recanalization of the coiled pseudoaneurysm was observed on follow-up imaging 3 months after the initial endovascular treatment. The patient subsequently underwent additional endosaccular coil embolizations for regrowth of the treated pseudoaneurysm buried in the VS. Two years later, another major recanalization was detected, prompting further retreatment. Subsequently, the patient has remained in a stable condition for 4 years. We suggest that endosaccular coil embolization of the distal AICA aneurysm with parent artery preservation might be a safe and feasible treatment option for radiation-induced saccular pseudoaneurysm arising from a large parent artery. However, close and regular follow-up imaging and preparation for potential retreatment are necessary, as pseudoaneurysms coiled within VSs are prone to recanalization.