Intradural Extramedullary Surgical Lysis of an Arachnoid Web of the Spine: 2-Dimensional Operative Video.

Arachnoid web of the spine (AWS) is a rare and subtle lesion that can have severe neurological consequences. Patients typically present with progressive myelopathic symptoms and have no more than a slight indentation of spinal cord on imaging, commonly referred to as the "scalpel sign." A unique feature associated with this lesion is the extent of (and sometimes the rapidity of) the recovery that occurs following treatment. In this operative video, we highlight the treatment of a 32-yr-old male with a history of lumbar spondylosis, who, over a 2 wk period, developed progressive spasticity and weakness of the entire left lower extremity and left foot numbness. Magnetic resonance imaging revealed a T4-T5 "scalpel sign" and spinal cord compression on computed topography myelogram, which was subsequently taken to the operating theater. The major steps in this video include the following: A) a summary of the patient's presentation and preoperative imaging, B) the technical steps in the surgical lysis of the AWS, and C) his postoperative course. The patient tolerated the procedure well, demonstrating a rapid improvement in symptoms postoperative day 1. At the time of most recent follow-up (4 mo), the patient remains neurologically intact with a full return to his neurologic baseline. Surgical lysis of AWS demonstrated to be a curative procedure with rapid neurological recovery, showing no signs of recurrence or regression. Consent was given by the patient for the use of deidentified images and the intraoperative video for educational purposes at the time consent was obtained for the surgical procedure, in accordance with our institution's policy.