Posterolateral cervical or thoracic approach with spinal cord rotation for vascular malformations or tumors of the ventrolateral spinal cord

This report describes a technique for exposing the ventrolateral quadrant of the spinal cord through an extended posterolateral approach that can be used in both cervical and thoracic regions. The surgical technique includes the following: 1) a midline skin incision with a transverse extension at the level of pathology; 2) unilateral division and retraction of the paraspinous muscles; 3) laminectomy and unilateral removal of facets and pedicles; 4) dural incision over the dorsal root entry zone; 5) multilevel division of the ipsilateral dentate ligaments; and 6) elevation and rotation of the spinal cord with dentate traction stitches. This technique provides exposure of the ventral root entry zone, the ipsilateral half of the ventral surface of the cord, and the anterior spinal artery. The surface of the spinal cord beyond the anterior spinal artery is not seen. This approach has been used for the treatment of seven ventrolateral spinal cord lesions: five spinal arteriovenous malformations (two Type II, one Type III, two Type IV), one hemangioblastoma, and one cavernous angioma. All the lesions were completely excised. Two patients had mild new neurological deficit after surgery, and one adolescent developed mild asymptomatic thoracic kyphosis, but no other spinal instability was observed over a follow up period of 1 to 4 years. This operative approach provides significant advantages for ventrolateral perimedullary or intramedullary lesions of the cervical or thoracic spinal cord.