Symptomatic delayed coil migration after balloon assisted embolization: An underreported adverse event?

Delayed intranasal coil extrusion after internal carotid artery pseudoaneurysm embolization

Internal carotid artery (ICA) injury is a rare but potentially life-threatening complication of skull base and neck surgery. Although usually manifested by massive intraoperative haemorrhage, impairment of the ICA might go unnoticed and result in formation of a pseudoaneurysm, causing delayed bleeding. Often additional complications are observed such as thrombosis, spasm, embolism or carotico-cavernous fistula formation. The risk of carotid artery injury in aggressive endonasal skull base surgical interventions ranges from 1% to 9%. Digital subtracted angiography remains the gold standard for evaluation of patients with iatrogenic carotid artery injury as it allows for endovascular treatment at the time of the procedure. Endovascular embolization is currently the preferred method for treating ICA pseudoaneurysms and a successful alternative to the surgical approach. Even though endovascular approaches are considered the safer option, delayed complications have been registered, such as endovascular coil extrusion and migration, which increases the risk of further episodes of bleeding. We present our experience with late coil extrusion in a patient who was previously treated with flow diverter stent and coiling for iatrogenic ICA pseudoaneurysm.