Catastrophic Rebleeding during Woven EndoBridge Treatment of a Large Ruptured Internal Carotid Artery Aneurysm with a Fetal-Type Posterior Communicating Artery: A Case Report

Intraprocedural rupture during Woven EndoBridge (WEB) treatment is most commonly reported in the early deployment phase, whereas rebleeding after substantial deployment is considered rare. We report a patient in their early 90s with poor-grade subarachnoid hemorrhage caused by a large ruptured internal carotid artery aneurysm with a fetal-type posterior communicating artery. After initial deployment, the bleb was already covered by the lateral surface of the device. During partial resheathing and repositioning to preserve the branch, the WEB rotated slightly, altering the configuration of the device relative to the bleb and thereby changing device-aneurysm wall interaction. Retrospective assessment of the procedural recording later suggested minimal contrast leakage just above the bleb, although massive hemorrhage became evident only during the final angiographic runs after detachment. Rescue treatment with balloon occlusion and n-butyl cyanoacrylate embolization achieved hemostasis; however, postprocedural cone-beam computed tomography revealed a massive intracerebral hematoma, and the patient died 3 days later despite supportive care. This case underscores that even after substantial deployment, repositioning maneuvers may carry a risk under specific high-risk conditions.