Intraluminal Shunt for the Thoracic Aorta: Blood Flow and Function in Chronic Studies

Background. Aortic cross-clamping during operations on the thoracic aorta may result in paraplegia or kidney failure. Methods. A nonshunting method of repair was compared with intraluminal shunting in two groups of young pigs: the no-shunt group, which received simple aortic cross-clamping at the ligamentum for 15 minutes; and the shunt group, which received an aortic graft with a temporary intraluminal shunt and balloon occlusion of the inferior vena cava only during shunt insertion and removal. Blood flow to the spinal cord and viscera was measured with radiolabeled microspheres on days 1, 3, 5, and 7 after operation. Renal and neurologic function and histology also were studied. Results. In the no-shunt group, there was hyperemia of the lumbar cord compared with the shunt group. There were no significant differences in renal cortex blood flow or creatinine clearance. Seven of 10 animals in the no-shunt group had paraplegia, compared with none in the shunt group. Histologic studies of the lower lumbar cord showed bilateral central necrosis of gray matter in the no-shunt group, but no evidence of necrosis in the shunt group. Conclusions. An intraluminal shunt allowed thoracic aorta reconstruction without paraplegia. (Ann Thorac Surg 1997;63:419–24)