Thoracic Intramedullary (Anterolateral) Cavernoma

Abstract

Resection of an anterolateral intramedullary lesion requires an approach that best provides a direct in-line access to the part of the lesion that presents at the pial surface, which enables total removal without injuring the spinal tracts. In Video 1, we show the technique of resection of an anterolateral intramedullary cavernoma. The vertebral level was identified before surgery, with coils placed percutaneously within the pedicle. A partial unilateral posterolateral approach was realized. During a posterolateral durotomy, the arachnoid was opened and hitched up with stay sutures. The dentate ligament was identified, cut, and then turned medially with a stitch to allow gentle rotation of the spinal cord to enable visualization of the anterolateral surface of the cord. This allowed us to bring the anterolateral subpial part of the lesion to a relatively more posterolateral position. A pial stitch was used to enhance and maintain the visualization of the lesion. The cavernoma was dissected circumferentially and removed in toto. The endoscope was used intermittently during the dissection to enhance the microscopic view, especially for the anterolateral surface. At the end of the excision, the arachnoidal edges were apposed and welded together using fine bipolar forceps at low-current setting under saline irrigation. The dura was closed watertight. The wound was closed in layers. The posterolateral approach combined with rotation of the spinal cord by dentate ligament stitch allows direct visualization for lesions that present onto the anterolateral surface of the cord.

Keywords: Costotransversectomy; Dentate ligament; Intramedullary cavernoma.