Intranasal coil protrusion after internal carotid artery embolization following endoscopic transnasal transsphenoidal surgery: A case report and literature review.

Background: Internal carotid artery (ICA) injury is a feared complication of transnasal transsphenoidal surgery (TNTS), with an incidence of 1-9%. Endovascular coil embolization remains a mainstay for managing ICA pseudoaneurysms; however, delayed complications such as intranasal coil herniation are exceedingly rare but potentially serious. Case Description: We report a 44-year-old male with a pituitary macroadenoma who sustained a left ICA injury during TNTS at a peripheral center. He was stabilized with nasal packing and referred to our institution, where coil embolization of the ICA pseudoaneurysm was performed. The patient declined definitive surgery at that time. Four years later, he presented with progressive visual decline. Imaging revealed coil migration into the nasal cavity. Pre-operative imaging highlighted a short intercarotid distance. Definitive endoscopic surgery was performed with intraoperative identification of herniated coils protruding into the sphenoid sinus. The coils were carefully trimmed to prevent entanglement, and tumor resection was successfully completed with preservation of both ICAs. Post-operative recovery was uneventful. Conclusion: Literature review revealed variable timelines of coil extrusion, with most cases managed endoscopically. Rebleeding, though rare, was documented in a few. Intranasal coil herniation is a rare, delayed complication requiring careful planning, radiological evaluation, and multidisciplinary management to prevent fatal outcomes.