Case Report: Percutaneous intercostal artery catheterization to treat a difficult-to-access spinal dural arteriovenous fistula

Patient information

An adult patient with no relevant medical history presented with intermittent upper and lower limb paresthesias and motor deficits, sometimes associated with cold sweats, nausea, and palpitations. She had no fever, recent trauma, or incontinence.

Physical examination revealed right lower-limb weakness and hyperalgesia.

Diagnostic assessment

CTA showed aneurysmal dilation of the descending aorta with a mural thrombus. T2-weighted MRI sequences showed centromedullary edema over multiple spinal cord segments and dilated and coiled posterolateral perimedullary vessels. MRA done to locate the suspected SDAVF showed early venous filling with an arteriovenous shunt at the right T10 level (Figure 1).

Figure 1. Imaging protocol.

[A] Volume rendering reconstruction from CTA shows the aneurysm and associated mural thrombus in the descending aorta; Sagittal [B] and axial [C] T2-weighted MRI show centromedullary edema and dilated perimedullary vessels. Axial [D] and coronal [E] first-pass contrast-enhanced MRA images show early venous filling (arrowheads) and the presumed shunt point (arrow) at the right T10 level.

DSA showed delayed venous return in the great anterior radiculomedullary artery originating from the right T11 segmental artery (not shown); however, the partially thrombosed aneurysmatic dilation of the aorta and the morphology and disposition of the thoracic segment precluded the catheterization of some lower thoracic segmental arteries.

Therapeutic intervention

Surgical repair failed because the intradural vein receiving blood from the shunt could not be identified. The interdisciplinary team decided on a combined surgical and endovascular approach in which a minimal partial posterolateral rib resection with the patient in left lateral decubitus position exposed the ventral branch of the 10th right posterior intercostal artery (Figure 2), which was catheterized with a 4F introducer set (4F Micro-stick introducer set, Medcomp) and a 0.014 inch microwire. DSA revealed early venous filling and retrograde contrast uptake of the upper and lower radiculomedullary veins, confirming the diagnosis of SDAVF (Figure 3).

Figure 2. Therapeutical procedure.

[A] Minimal partial posterolateral rib resection with the patient in left lateral decubitus to expose the ventral branch of the 10th right posterior intercostal artery. [B, C] Catheterization of the ventral branch of the 10th right posterior intercostal artery with a micropuncture set and a 0.014-inch microwire.

Figure 3. Endovascular procedure.

[A] Unsubstracted fluoroscopic image showing the intercostal access and opacification of the Spinal dural arteriovenous fistulas (SDAVF) at the T 10 level. Superselective injection and 3D rotational DSA with MIP reconstruction [B] show the feeding artery (arrowhead), the shunting zone (arrow), and the proximal draining vein (asterisk). [C, D] Exclusion of the SDAVF after embolization and coil placement in the segmentary artery. [E] Sagittal Short tau inversion recovery (STIR) MRI image 3-months after treatment showing less evident cord edema.

Injection from the segmental artery verified the absence of supply to the spinal cord from the pedicle feeding the SDAVF. After 3D-rotational DSA to better characterize the lesion, we injected approximately 0.5 cc of ethylene vinyl alcohol copolymer (SQUID-18, Emboflu; Gland, Switzerland, supplied by Balt) into the fistula with little pass to the draining vein. Finally, we placed a coil in the segmentary artery to mark the level of the fistula. Control images demonstrated the exclusion of the fistula and patency of the segmental artery (Figure 3).

Follow-up and outcomes

The patient was discharged without complications after 2 days.

At follow-up, her lower limb strength had improved and on follow-up MRI three months after procedure (Figure 3) the prominent perimedullary vessels and cord edema were less evident. Even though there was not complete pass to the draining vein, it was enough to diminish the flow to the fistula and to get symptomatic relief.

Patient perspective

“My family and I had a bad time when the neurologic symptoms started and progressed. I had great support during and after the treatment. I’m walking again and taking care of my grandchildren. I’m really grateful with Dr. Rodríguez and his team.”