Neurological deficit from a purely vascular etiology after unilateral vessel ligation during anterior thoracolumbar fusion of the spine

Study Design. Comprehensive analysis of patient records who underwent anterior approach to the thoracolumbar spine at a single institution. Objectives. To report on neurologic deficit from a purely vascular injury to the spinal cord occurring after unilateral anterior thoracolumbar spinal surgery that did not involve additional correction or other etiologies. Summary of Background Data. The largest study in the literature regarding the risks of neurovascular deficit during anterior exposure of the thoracolumbar spine reports that there exists no risk with unilateral ligature of the segmental arteries. Methods. The records and operative notes of 265 consecutive patients were reviewed. All adult neurologically intact patients, average age 40.2 years (range 18-85 years) who have had surgery between 1985 and 2002 that involved anterior approach to the thoracic spine were included. Segmental arteries were ligated midbody, away from the foramen and the aorta. Seventy-two percent of the approaches were left-sided. An average of 5.1 unilateral segmental artery ligations were performed per procedure. Results. Two patients out of 265 had major neurologic deficit after anterior thoracolumbar approach. Both patients had staged procedures: posterior spinal fusion then anterior spinal fusion to the thoracolumbar spine. One deficit occurred immediately after surgery and the other occurred 24 hours after surgery. No additional corrective maneuvers were performed; neither patient was hypotensive, nor did they experience blood loss anemia and their postoperative computed tomography myelogram study was normal. Conclusion. Neurologic deficit after anterior exposure to the thoracolumbar spine occurred in 0.75% of patients in this study exclusively from unilateral left-sided ligation of the T10-T12 segmental vessels. Both patients had common risks of prior kyphosis correction, revision surgery and left-sided approach.