Eight patients with aneurysm of varying origins have had resection and graft replacement of the descending thoracic aorta with aid of vascular prosthesis bypass, partial left heart pump bypass, or femoral vein to femoral artery oxygenation bypass. All survived operation without post-operative renal malfunction and caudal neurologic deficients. Hemodynamic and enzymologic examinations reveal that the last adjunct procedure is most beneficial.