ABSTRACT
Jeffrey L. Ballard End-organ damage from ischemia and reperfiision of abdominal viscera, spinal
cord and lower extremities contributes greatly to the morbidity and mortality asso ciated with thoracoabdominal aortic aneurysm (TAA) repair. Adjunctive techniques such as left heart bypass with distal aortic and visceral perfusion, cerebrospinal fluid (CSF) drainage, monitoring of spinal somatosensory evoked potentials, reattach ment of intercostal arteries, epidural cooling, passive hypothermia, cardiopulmo nary bypass with hypothermia and profound hypothermic circulatory arrest are all selectively utilized in order to diminish this end-organ ischemia. These adjuncts appear to be successful in decreasing morbidity and mortality particularly associated with repair of type I and II TAAs which extend from the subclavian artery to above the celiac axis or opposite the superior mesenteric artery (SMA) but above the renal arteries (type I), or through the visceral vessels to the aortic bifurcation (type II). However, even those who have championed these methods do not necessarily use them for repair of type III or IV TAAs where the risk of spinal cord ischemia is less but the risk of gastrointestinal, hepatic, renal and lower extremity ischemia remains the same. These TAAs involve all four visceral vessels and extend through the aortic bifurcation with a type III beginning in the mid-descending thoracic aorta and a type IV beginning at the diaphragm.
