Endovascular treatment in spinal perimedullary arteriovenous fistula

Abstract

This study includes 20 patients with 21 spinal perimedullary fistulae. There were nine Type IVa (42.8%) lesions, ten Type IVb (47.6%) and two Type IVc (9.5%) lesions. The dominant arterial supply was from the anterior spinal artery (47.6%), posterior spinal artery (19%) and directly from the radiculomedullary artery (28.5%). Sixteen lesions in 15 patients were treated by endovascular route using n-butyl-2-cyanoacrylate. Endovascular treatment was not feasible in five patients. Of the ten patients with microfistulae, catheterization failed/was not attempted in 40%, complete obliteration of the lesion was seen in 60% but clinical improvement was seen in 40% of patients. Catheterization was feasible in all ten patients with macrofistulae (nine type IVb and two type IVc lesions). Complete obliteration of the lesions was seen in 60% and residue in 30%. Clinical improvement was seen in 80% and clinical deterioration in 10%. In conclusion, endovascular glue embolization is safe and efficacious in type IVb and IVc spinal perimedullary fistulae and should be considered the first option of treatment. It is also feasible in many of the type IVa lesions.

Keywords: embolization; perimedullary arteriovenous fistula; spinal cord.

Figure 1

A type IVa lesion of the conus region in a 46-year-old woman shows the long course of the anterior spinal artery feeding a small AVF (A) and the accompanying vein (B). Distal microcatheterization failed in this case.

Figure 2

A cervical type IVa lesion fed by the anterior spinal artery treated surgically 20 years earlier in a 52-year-old man. A) Rt vertebral angiography before surgery. B) Recurrence fed by Rt thyrocervical branch. C) The microcatheter tip is a little far from the fistula. D) Adequate glue cast reaching to the foot of the vein. E) Angiographic check in Rt thyrocervical trunk.

Figure 3

Case No. 15. A radiculomedullary artery feeding a type IVb lesion shows an aneurysmal dilatation close to the lesion. A) It also sends a twig to the descending anterior spinal artery before the fusiform aneurysm. B) Also note a posterior spinal feeder arising from the same intercostal artery, the aneurysm was coiled (black arrow). C) Check angiography shows a residual AVF and descending anterior spinal artery. The lesion required two subsequent sessions to complete the obliteration.

Figure 4

Case No. 7. A) MRI T2 weighted image in a 23-year-old man shows cord oedema and flow voids in the subarachnoid space in the thoracolumbar region. B) Left L2 injection shows ascending limb of RMA supplying a type IVa lesion. C) Venous phase. D) Microcatheter close to the fistula site. E) Precise glue cast taking the distal part of the feeder, the fistula and early part of the vein.

Figure 5

A cervical type IVb lesion fed by the RMA from the left vertebral artery (A) in a 24-year-old woman. B) Venous phase. C) Microcatheter close to the fistula. D) Post-embolization check angiogram. E) Glue cast. F) Large linear epidermal naevus on the neck and face.

Figure 6

MRI in a 2-year-old girl shows cord oedema and flow voids (A). B) Angiography reveals a large RMA feeder from the rt D8 intercostal artery. C) Venous drainage flows inferiorly and then exists the dural sac to flood the vertebral venous plexus and azygous system. D) Check angiogram after embolization. E) Glue cast.

Figure 7

A large type IVc lumbar lesion in a 6-year-old girl fed by a PSA feeder from the left L2 level (A). B) An ASA feeder from left L1 level. C) Microcatheter injection in the PSA feeder. D) Hyperform balloon inflated in the left L1 lumbar artery to reduce flow. E) Microcatheter injection in the ASA feeder after glue injection in the PSA feeder, F) Glue cast in the sac as well as the distal part of feeders. Check angiography shows preserved ASA axis (black arrow) (G) and PSA (white arrow) (H).