External Carotid Artery-to-Vertebral Artery Bypass With Craniocervical Vertebral Artery Decompression for Vertebrobasilar Insufficiency

BACKGROUND AND OBJECTIVES: Vertebrobasilar insufficiency (VBI) is a hemodynamic condition characterized by reduced perfusion to the posterior circulation causing vertigo, dizziness, and focal neurologic deficits. While medical and endovascular therapies have improved outcomes for many patients, a subset with medically refractory symptoms remains. Patients with severe stenosis or occlusion of the dominant vertebral artery are at particularly high risk. Although external carotid artery (ECA)-to-vertebral artery (VA) bypasses have been described, they involve significant technical complexity and high surgical risk. Moreover, significant dynamic compression of the vertebral arteries may persist at the craniocervical junction. In this series, we report the results of ECA-to-V3 VA bypass and V3 atlantoaxial decompression. METHODS: A retrospective cohort study was conducted in patients with medically refractory VBI who underwent ECA-to-V3 VA bypass and decompression between 2007 and 2025. Demographic, clinical, and radiographic data were obtained by chart review with independent angiographic analysis. The primary outcome was long-term symptom-free survival. The secondary outcomes included perioperative complications and long-term morbidity. RESULTS: Fifteen patients underwent ECA-to-V3 VA bypass and decompression, with a cumulative follow-up of 44.3 person-years. Dizziness was the most common presenting symptom (93.3% of patients), and nearly all patients had hypertension and hyperlipidemia (92.9%). While short-term and long-term improvement in symptoms was 100%, durable symptom-free survival was achieved in 75% of patients. No perioperative neurological complications or deaths were observed. Chronic neck pain was the most frequent long-term complication, affecting 42.9% of patients. CONCLUSION: ECA-to-V3 VA bypass with atlantoaxial decompression is a safe and effective surgical option for patients with medically refractory VBI, offering durable symptom control and a low risk of neurological complications. Although postoperative neck discomfort is not uncommon, the overall safety profile and efficacy of the procedure support its consideration in carefully selected patients.