Hypothermic thoracic and thoracoabdominal aneurysm operation: a central cannulation technique.

Surgical resection of the descending thoracic and thoracoabdominal aorta is associated with the risk of spinal cord ischemic injury, particularly in patients with aortic dissection. Hypothermic total cardiopulmonary bypass with periods of circulatory arrest has been advocated for spinal cord protection with encouraging early results. However, techniques for this procedure are relatively complex. An alternative cannulation technique with venous return from the right atrium through the internal jugular vein and arterial return to the aortic arch is described. This has been used in 6 patients for replacement of the descending thoracic or thoracoabdominal aorta. Despite profound hypothermia and preservation of the principal spinal radicular artery, 1 patient suffered early paraparesis with some recovery but eventually died of multisystem failure. A second elderly patient with severe obstructive airways disease died of respiratory failure 11 days postoperatively. Four patients made a good recovery including 1 with a ruptured thoracoabdominal aneurysm who subsequently required gut resection for ischemic necrosis present preoperatively. This cannulation technique together with profound hypothermia has greatly improved the operating conditions for extensive aneurysms of the thoracoabdominal aorta. Paraparesis occurring despite hypothermic protection and attempted preservation of the spinal cord arterial supply suggests that unfavorable vascular anatomy still predominates in the risk factors for ischemic injury.