Microsurgical obliteration of C1 dural arteriovenous fistulas via a unilateral partial C1 hemilaminectomy: technical note

Dural arteriovenous fistulas (DAVFs) at the C1 level are rare, and conventional microsurgical treatment requires extensive bone resection. We hypothesized that C1 DAVFs supplied exclusively by dural branches of the vertebral artery (VA)—without intradural feeders—could be obliterated via a unilateral partial C1 hemilaminectomy. We retrospectively analyzed patients surgically treated for C1 DAVFs (January 2019–December 2024). Inclusion criteria required symptomatic fistulas supplied exclusively by dural VA branches, without ascending pharyngeal supply or an intradural feeder, on preoperative digital subtraction angiography (DSA). Via a partial C1 hemilaminectomy, the arterialized draining vein was exposed and obliterated. Three of five patients met the inclusion criteria (mean age, 61.3 years); all had Cognard type V fistulas. Presentations included subarachnoid hemorrhage ( n = 1) and myelopathy due to venous hypertension ( n = 2). In all cases, the hemilaminectomy provided sufficient exposure to identify, coagulate, and divide the fistulous connection. Postoperative DSA confirmed complete obliteration in all patients. One patient had transient occipital hypoesthesia that resolved within three months; there was no permanent morbidity. At one year, motor deficits and cord signal changes had fully resolved in both myelopathic patients, but neurogenic bladder improved only partially in one and persisted in the other; no recurrence was observed. When ascending pharyngeal supply and intradural feeders are absent on preoperative angiography, a unilateral partial C1 hemilaminectomy can achieve complete obliteration without conventional extensive bone resection.