OPERATIVE RESULTS OF THORACOABDOMINAL REPAIR FOR CHRONIC TYPE-B AORTIC DISSECTION

From January 1991 to May 1994, we have operated. on 15 cases of Type B aortic dissection. In 10 of these patients, thoracoabdominal repair w as performed. According to Crawford's classification, 2 patients fell into Type I, 6 patients into Type II, and 2 patients into Type III. Th e aneurysms were exposed through a left thoracotomy extending into the retroperitoneum with the hemidiaphragm divided circumferentially. The operations were performed under femoro-femoral partial cardiopulmonar y bypass. in 6 of these cases selective perfusion of the visceral bran ches was used. The celiac axis was reconstructed in 10 patients, super ior mesenteric artery in 3, right renal artery in 7, left renal artery in 6. Abdominal vessels were reconstructed by the ''inclusion'' techn ique described by Crawford in 2 patients, by ''beveling'' the distal p rosthetic end in 6 and by. the ''interposition'' technique in 4 patien ts. Vessels arising from the false lumen were reconstructed by the ''i nterposition'' technique. To prevent paraplegia, the evoked spinal cor d potentials by direct stimulation of the cord (ESPs-dsc) were monitor ed perioperatively and the aneurysms were repaired sequentially in seg ments. In all patients except 2 with Crawford type III aneurysms, spin al cord ischemia was detected by ESPs-dsc. In 7 of these patients, 2 t o 8 pairs of intercostal/lumbar arteries (I/L aa.) that arose from the ''responsible'' aortic segment were reconstructed. Reconstruction tec hniques included the ''inclusion'' technique in 2 patients, the ''beve ling'' technique in 1, the ''interposition'' technique in 1 and the '' on lay grafting'' technique in 3 patients. One hospital death occurred in a patient who had chronic renal insufficiency and Liver cirrhosis preoperatively. Spinal cord injury occurred in 5 patients, including 4 paraparesis and 1 delayed-onset paraplegia In 2 of these patients, re sponsible I/L aa, were not reconstructed correctly despite ESPs change s, and injury might have been prevented if reconstruction of the ''res ponsible'' arteries had been performed. Thoracoabdominal repair for ch ronic Type B aortic dissection could be performed safely with an accep table mortality rate. Spinal cord injury remains an unsolved problem.