Spinal osseous epidural arteriovenous fistula with multiple small arterial feeders converging to a round fistular nidus as a target of venous approach

Abstract

We present two patients with spinal epidural arteriovenous fistulas involving the vertebral body recruiting dural and osseous branches as feeders. The fistulas, forming a round venous sac into which the multiple arterial feeders converge, were located near the round bony defect of the vertebral body, suggesting the osseous component of this vascular lesion. Transvenous coil embolization of the round venous sac results in near-total obliteration of the lesion, leading to symptomatic improvement.

Fig 1.

Patient 1, a 50-year-old female patient presented with severe radicular pain and bruit in the right cervical neck. Bone window setting of axial CT scan (A) reveals a bony defect with loss of cortical margin in the right side of the C5 body and pedicle corresponding to the area of the dilated venous sac. Anterioposterior views (B and C) of a right vertebral and costocervical arteriogram show multiple fine feeders of fistula draining into a dilated venous sac and cephalad epidural vein. Selective venogram (D) through the microcatheter was obtained in the dilated venous sac. Vertebral angiogram (E) obtained 4 months later reveals reduction of the fistula with a small residual shunt. The pain and bruit disappeared.

Fig 2.

A 21-year-old female patient presented with both lower leg weakness and voiding difficulty. Sagittal T2-weighted MR image (A) shows the high signal intensity of the diffusely swollen spinal cord. Note the tortuous vessels around the cord surface. Arterial phase of the L2 lumbar artery (B) shows multiple fine feeders of fistula draining into the dilated epidural venous sac. Venous phase (C) of the upper level shows medullary venous engorgement and venous drainage through the hemiazygos vein into the opening site of the azygos vein to the superior vena cava (arrow). Final angiogram (D) after GDC embolization shows complete obliteration of the fistula. Sagittal T2-weighted image (not shown) obtained 6 months later shows the normalized contour and signal intensity of the spinal cord. Contrast-enhanced axial T1-weighted image (E) reveals low signal intensity of the packed coils within the bony defect of the L2 body and pedicle maintaining dural integrity at the site of the dilated venous sac. The patient’s neurologic deficit had disappeared completely.