Intracranial dural arteriovenous fistula associated with a spinal tumor: a case report.

Abstract

Dear Editor, We would like to present the case of a patient with a transverse-sigmoid dural arteriovenous fistula (DAVF) associated with a spinal dumbbell schwannoma. Intracranial DAVFs are characterized by an arteriovenous (AV) shunt between the dural arteries and major intracranial dural sinuses [1]. Predisposing causes have been reported to be the presence of an intracranial brain tumor [3], a past history of intracranial surgery [6], head trauma [2], and brain infarction [4]. The most frequent brain tumor in patients with DAVFs is meningioma, which commonly develops adjacent to, and invades into, the dural sinuses [3, 5, 7, 8]. To our knowledge, there have been no case reports of an intracranial DAVF associated with a spinal tumor. A 70-year-old female had become aware of a ‘floating’ gait 10 years prior to admission and later noticed bilateral pulsating tinnitus 2 years prior to admission. On admission, neurological examination revealed slight right spastic hemiparesis, sensory disturbances in the peripheries of the upper and lower extremities, and the Romberg sign. Spinal MR imaging revealed an extramedullary spinal dumbbell tumor, which significantly compressed the spinal cord at the C2 level (Fig. 1). There were many flow voids in the posterior cervical muscle layers around the tumor. Digital subtraction angiography revealed a right transverse-sigmoid DAVF without cortical venous reflux. There were multiple AV connections between the dural arteries and the transverse and sigmoid sinuses mainly at the sinus confluence; these dural branches were fed predominantly by the right vertebral artery as well as the bilateral maxillary and occipital arteries. Contrast-enhanced CT revealed that the right internal carotid vein was severely compressed at the right C2 level between the spinal tumor and anterior deep cervical muscles originating from the right styloid process. As a result, the right internal carotid vein was thrombosed, and the thrombus progressed into the right jugular foramen to the sigmoid sinus (Fig. 1d). Arterial blood flow into the DAVF drained out via the enlarged right condylar emissary vein into the deep cervical vein. We planned to treat the DAVF with endovascular embolization before open surgery because there was massive venous drainage around the tumor and severe bleeding during tumor removal was predicted. First, dural arteries were occluded with NBCA via a transarterial approach. Then, the deep cervical vein was occluded with NBCA via a transvenous approach. Finally, the right transverse and sigmoid sinuses were packed with coils, leading to the occlusion of the DAVF. In the second stage, we performed open surgery via a posterior midline approach. During surgery, bleeding was wellcontrolled because most of the deep cervical veins were occluded with NBCA. The dumbbell tumor, which was mostly located in the epidural space, was extensively removed, piece by piece, leading to successful decompression of the spinal cord. Total blood loss was 312 ml. The pathological diagnosis was schwannoma. * Keisuke Takai takai-nsu@umin.ac.jp