Ruptured Aneurysm of an Aberrant Internal Carotid Artery Successfully Treated with Simultaneous Intervention and Surgery in a Hybrid Operating Room

Background Aberrant internal carotid artery (aICA) is an anatomic anomaly whereby the internal carotid artery courses through the tympanic cavity without separation by bone. Because aICA is rare, there are no definite treatment strategies for aICA and its complications. Case Description We report a case of aICA accompanied by pseudoaneurysm formation and massive bleeding. The patient was a 31-year-old woman with a 2-year history of hearing loss, ear fullness, and pulsatile tinnitus in her left ear. After a diagnosis of otitis media with effusion, she underwent a myringotomy and massive arterial bleeding occurred. After the bleeding was temporarily stopped, aICA and pseudoaneurysm formation on the aICA were shown. To prevent rebleeding, we performed endovascular internal trapping around the pseudoaneurysm after performing common carotid artery to radial artery to middle cerebral artery bypass grafting. After surgery, the aneurysm disappeared. In addition, no new neurologic complications were observed, and the patient's hearing improved and the tinnitus diminished. Conclusions This is the first case report of an aICA complicated by pseudoaneurysm formation successfully treated with simultaneous endovascular trapping and high-flow bypass in a hybrid operating room.