Microsurgical Excision of T12-L1 Pial Arteriovenous Malformation: 3-Dimensional Operative Video

This 29-yr-old man presented with progressive paraparesis, sensory loss, allodynia, bowel, and bladder dysfunction for 9 mo, acutely exacerbated in the preceding 24 h. Magnetic resonance imaging scan showed multiple dilated vessels involving the thoracic cord. Spinal angiogram revealed a T12-L1 pial arteriovenous malformation (AVM)/arteriovenous fistula on the left side. It was fed by an L1 radicular artery that filled the anterior spinal artery, which in turn had multiple feeders to a pial AVM. Because of the supply from the anterior spinal artery with multiple feeders to the AVM, and the danger of infarction of the conus, embolization was not performed. He underwent T11-L1 laminectomy laterally to the pedicles and excision of AVM. There was one large arterialized vein in the midline that had a fistulous connection with an artery coursing up from inferiorly. Despite occlusion of this fistula, the vein was still arterialized. On further exploration, there was a large artery coming in to the subarachnoid space at the T11 level and coursing inferiorly, and entering the intradural pial AVM with a glomus of vessels located at the T12 level in the left anterolateral subpial aspect of the cord. This major artery as well as multiple smaller vessels going into it were cauterized and divided, and the AVM was totally excised. Postoperative angiogram showed complete excision of the nidus. At 1 mo follow-up, he had complete recovery of motor and bladder functions but bowel dysfunction persisted. He was independent for his daily activities. Informed consent was obtained from the patient prior to the surgery that included videotaping of the procedure and its distribution for educational purposes. All relevant patient identifiers have also been removed from the video and accompanying radiology slides.