Extracranial-Intracranial (EC-IC) Bypass for Carotid Complications in Irradiated Head and Neck Cancer Patients

Background: Carotid complications represent a serious sequela in patients with previously irradiated head and neck cancers. Carotid blowout syndrome, often secondary to pseudoaneurysm formation, can be fatal, whereas carotid occlusion may result in stroke-like symptoms. An extracranial–intracranial (EC–IC) bypass surgery, which harvesting a vessel graft and bypass the threatened or occlusive ICA offers a means of maintaining adequate cerebral perfusion in this high-risk population. We present a case series of patients with prior head and neck cancer treatment who developed carotid complications and subsequently underwent EC–IC bypass surgery, with emphasis on preoperative considerations and surgical planning. Methods: We retrospectively reviewed patients who underwent EC–IC bypass between 2014 and 2025. Clinical data including cancer type and stage, presenting symptoms, vessel graft types, and recipient vessels were analyzed. Results: Eleven patients underwent EC–IC bypass, including four bilateral cases. The mean age at surgery was 49.1 ± 10.4 years (median 50.2). All were male, with four (36%) received re-irradiation. The interval between radiotherapy and bypass surgery was 11.5 ± 8.9 years (median 10, range 1–32 years). Ten patients had a history of nasopharyngeal carcinoma, and one had oropharyngeal carcinoma. Grafts included six saphenous veins and nine radial arteries. Ten grafts were anastomosed to M2 segment while 5 were to M3 segment. Two perioperative complications were recorded: one postoperative hemorrhage attributed to hyperperfusion and one intracranial abscess. A schematic of the preoperative evaluation process is presented in [ Figs. 1 ] and [ 2 ]. Conclusion: In this series, re-irradiation for nasopharyngeal carcinoma appeared to be a potential risk factor for carotid complications necessitating EC–IC bypass. While most patients developed complications more than a decade after radiotherapy, earlier onset within two years was also observed. Graft selection remains a critical factor in surgical planning. Overall, EC–IC bypass is a feasible and safe option that can preserve cerebral perfusion and improve quality of life in this complex patient population. Fig. 1 Clinical management pathway for carotid complications following head and neck irradiation Fig. 2 Algorithm of vessel graft selection Publication History Article published online: 27 February 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany