Evolving concepts in prevention of spinal cord injury during operations on the descending thoracic and thoracoabdominal aorta.

Spinal cord injury following operations on the descending thoracic or thoracoabdominal aorta remains a major problem. In certain subsets of patients, the risk of postoperative spinal cord injury is substantial. Although several adjuncts have been employed clinically to eliminate or reduce the frequency of this complication, none have proven to be completely effective. An important reason for this is the failure of these techniques to reliably and noninvasively localize the level of origin of arteries from the aorta that are critical to spinal cord circulation. Since postoperative spinal cord injury most likely results from ischemia or hypoxia of the lower segment of spinal cord, use of adjunctive techniques to preserve spinal cord function during aortic clamping by perfusing the distal aorta adequately with or without systemic hypothermia should be considered. To practically implement this, partial cardiopulmonary bypass for distal perfusion when the critical intercostal or lumbar arteries originate from the aorta distal to the excluded segment, and total cardiopulmonary bypass with systemic hypothermia and implantation of intercostal and lumbar arteries when these arteries originate from the excluded segment, can be used. In addition, whenever possible, intraoperative monitoring of spinal cord function should be performed.