Open distal anastomosis in conjunction with partial cardiopulmonary bypass and mild hypothermia for repair of descending thoracic aortic aneurysms.

The duration of spinal cord ischemia is probably the most important single factor in the pathogenesis of paraplegia after repair of descending thoracic aortic aneurysms. We describe a modification of open distal anastomosis technique originally presented by Dr. Cooley, in which we use partial cardiopulmonary bypass with femoral cannulation and mild hypothermia. Cardiopulmonary bypass is interrupted after lowering patient's temperature to 32 degrees C and the aorta is clamped using one proximal clamp. During the suturing of the distal anastomosis blood is sucked to reservoire and returned oxygenated to the patient via the venous line using a shunt which is installed between the arterial and venous lines. After completion of the distal anastomosis the graft is clamped and cardiopulmonary bypass reinstituted. Rewarming is started as bleeding intercostal arteries are sutured and proximal anastomosis performed. This modification shortens the distal ischemia time, but supports the circulation of the kidneys and splanchnic area immediately after the distal anastomosis is finished. Lowering the temperature should give additional protection for the spinal cord and the blood can be returned oxygenated to the patient. In our opinion, this combination of femoro-femoral perfusion, mild hypothermia, and open distal anastomosis offers several benefits and can be used in dissections and aneurysms, which extend up to aortic hiatus.