Transcanal Approach for Removal of Displaced Petrous Carotid Aneurysm Embolization Coil in the Middle Ear

Introduction: Aneurysms arising from the petrous segment of the internal carotid artery (ICA) are rare. Surgical treatment of petrous ICA aneurysms can be challenging due to their close proximity to inner ear structures. In this case, a rare complication of endovascular coiling is described of a patient who presented with ear bleeding, pulsatile tinnitus, and hearing loss shortly after undergoing the embolization procedure. This case report describes our unique management of the patient through intraoperative removal of the displaced coil through a transcanal approach and correction of the tympanic membrane perforation.

Case Description: Patient is a 55-year-old woman who was found to have a left petrous ICA aneurysm coursing through the middle ear cavity over the cochlear promontory. She underwent endovascular stenting and coiling of the left petrous ICA. However, immediately after the surgery, the patient had ear bleeding, acute loss of hearing in the left ear, as well as complaints of pulsatile popping and crackling sounds in the ear. Physical examination revealed a tympanic membrane perforation and extrusion of the embolization coil through the perforation. She was scheduled to undergo a transcanal approach to access, clip, and remove the coil from the middle ear.

Procedure: Exploration of the middle ear revealed that the ossicular chain was eroded at the level of the incus, and that the coil was filling the majority of the middle ear space. Excess coil was clipped and removed from the middle ear. A conchal bowl cartilage graft was removed and fashioned to be placed medial to the tympanic membrane remnant and lateral to the remaining middle ear, coiling to prevent future extrusion of the coil.

Follow-Up: On follow-up 1 month after the procedure, the patient was satisfied to have resolution of her pulsatile crackling and popping sounds. On examination, the cartilage graft was well in place, with complete epithelialization of the tympanic membrane perforation. On 4-month follow-up, she remained free of any ear infections, continued to demonstrate full closure of the perforation with cartilage graft in place, and had no symptoms of tinnitus.

Conclusions: This case is a rare example of a complication arising from endovascular treatment of petrous ICA aneurysms using coil embolization. As evidenced in this case, close attention should be given to otologic symptoms postoperatively after endovascular embolization of petrous ICA aneurysms.

Our surgical technique to remove the excess coil, and repair the tympanic membrane provided the patient with improvement of her symptoms. In particular, the use of a cartilage graft to protect the remaining coil from protruding through the tympanic membrane proved especially useful.