Direct Surgery for Spinal Arteriovenous Fistulas of the Filum Terminale With Intraoperative Image Guidance

Abstract

A technical case report of direct surgery for spinal arteriovenous fistulas of the filum terminale. We present 2 cases of spinal arteriovenous fistulas of the filum terminale directly fed by the anterior spinal artery that were successfully obliterated with intraoperative image guidance such as digital subtraction angiography, intra-arterial dye injection technique, or indocyanine green video angiography. The goal of direct surgery for spinal arteriovenous fistulas is the complete obliteration of shunt vessels while preserving the normal circulation of spinal cord. Safe isolation of feeding arteries, nidus, and draining veins needs to be obtained first. Vascular flow or anatomical orientation of shunt vessels also needs to be ensured with intraoperative image guidance. Two cases are presented. The first patient (case 1) had the lesion with a nidus formation at the L2 spinal level supplied directly by the anterior spinal artery via left L1 segmental artery. The second patient (case 2) had a lesion at the L4-L5 spinal level also supplied directly by the anterior spinal artery via the left T11 intercostal artery. Standard exposure of the lesion followed intraoperative image guidance to achieve the appropriate vascular flow or anatomical orientation of the shunt vessels. Complete obliteration of shunt vessels was successfully achieved without any complications in both cases. Although intraoperative image guidance is certainly not a prerequisite, the concept of safe and minimally invasive surgery makes it indispensable. It can facilitate identification of crucial or important landmarks where anatomic structures may be distorted.