To explore the clinical features, diagnosis and surgical strategy of the dural arteriovenous fistula (DAVF) at the foramen magnum.

12 cases of occipital large pore area DAVF admitted to Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School from January 1, 2015 to December 31, 2020, among whom there were 10 males and two females aged from 27 to 61 years, were retrospectively analyzed. The cranial computerized tomography scans of all patients showed subarachnoid hemorrhage in 11 patients, abnormal vessels in the craniocervical region revealed by CTA in three patients. Pre-operative digital subtraction cerebral angiography showed a DAVF at the foramen magnum. The lesion located in the right side in 9 cases and left side in three cases. Nine DAVFs were fed by the meningeal artery from vertebral artery, whilst the others were fed by dural branches of the vertebral artery, occipital artery and/or the ascending pharyngeal artery. The far lateral suboccipital approach was performed with hemilaminectomy of C1 and C2. Surgical and postoperative conditions of patients with DAVF were analyzed.

11 patients underwent direct microsurgical electrocoagulation and disconnection of the arteriovenous shunt. One patient underwent resection of fistula and tortuous enlarged varix through the help of endovascular balloon control for the vertebral artery in the hybrid room via an enlargement of the foramen magnum and a hemilaminectomy at C1 by the far lateral suboccipital approach. Post-operative angiography confirmed complete obliteration of the fistula. All patients were uneventful except one patient with serious disability due to brainstem injury.

The far lateral suboccipital approach is suitable for operative exposure of a DAVF at the foramen magnum. It can be treated effectively and with minimal surgical trauma by microsurgical electrocoagulation and disconnection of the shunt. Attention should be taken for prevention of injury to normal vital vessels to the brainstem.