Transradial Approach for the treatment of a sacral dural arteriovenous fistula: how far can we go?

Abstract

Sacral dural arteriovenous fistulae (SDAVFs) are rare, constituting no more than 10% of all spinal dural fistulae. They are most commonly fed by the lateral sacral artery (LSA), a branch of the internal iliac artery (IIA). Catheterization of this vessel requires either a cross- over at the aortic bifurcation in case of right femoral access or retrograde catheterization from the ipsilateral common femoral artery. We present the case of a 79-year-old male with tethered cord syndrome and a symptomatic SDAVF fed by two dural branches from the left LSA (A,B). Spinal diagnostic angiography was made exceptionally challenging by an aorto-bi-iliac endograft, and selective catheterization of the left IIA was not possible (C). Given suboptimal cardiovascular profile and the tethered cord, consensus was to proceed with endovascular embolization. Right trans-radial approach (TRA) was chosen in order to have the straightest path possible for selection of the left IIA with the guiding catheter. A 6F dedicated glidesheath was introduced under ultrasound guidance in the right radial artery and a 6F, 131 Cm Sofia Plus catheter was navigated retrogradely until the left IIA, negotiating the aorto-iliac graft with an 0.038, 180 cm wire. A 165 cm Apollo microcatheter was advanced over a 0.007 Hybrid microwire into the LSA until the most distal fistulous point, which was embolized with Onyx 18 (figure D). The second, proximal feeder was selected with a 165 cm Magic 1.2 and was embolized with a 2:1 mixture of glue (NBCA) and Lipiodol (E), successfully occluding the SDAVF (F).Recently, TRA has gained more popularity in the neuroendovascular field. Advantages include fewer haemorrhagic complications (notably eliminating the risk for retroperitoneal hematoma) increased post-procedural comfort and access to vessels that would not be reachable through transfemoral approach. Device size and length are key considerations. Most radial arteries accommodate 6F sheaths, although successful usage of 8F systems has been reported for arteries larger than 2.5 mm. In distal lesions device length can also be a problem, as the treatment target might be too distal even for the longest microcatheter. We pre-operatively measured the length of right arm and abdomen in order to choose catheters long enough to not run out of length. The presented case is, to our knowledge, the first report of a spinal vascular malformation treated by TRA. This approach, granted appropriate equipment selection, can allow treatment of spinovascular pathologies with an otherwise unfeasible aorto-iliac anatomy.