Preventing Renal Failure in Thoracoabdominal Aortic Aneurysm Repair

In our cumulative experience of 1004 thoracoabdominal and descending thoracic aortic aneurysm repairs, approximately 20% of patients have suffered from some form of postoperative renal dysfunction. Although slightly lower than rates in the era of cross-clamp-and-go, the contemporary incidence of renal failure and consequent morbidity and mortality remain significant. Between January 1991 and February 2003, we used and appraised many different forms of renal protection. After September 1992, we began to routinely use the adjuncts of distal aortic perfusion and cerebrospinal fluid drainage for all thoracoabdominal and descending thoracic aortic aneurysm repairs. The methods we examined for renal protection included aortic perfusion, followed by warm blood visceral perfusion, antegrade cold blood visceral perfusion, retrograde cold blood perfusion, and the perioperative use of a renal protective pharmacologic agent, fenoldopam. The results were not overly promising. We are currently testing a method of split perfusion in which the renal arteries receive cold lactated Ringer's solution while the visceral arteries are perfused with cold blood. The major predictors of postoperative renal dysfunction are preoperative renal function, cross-clamp time, and repair extending to the renal arteries. Distal aortic perfusion is protective, but only for aortic repair that does not directly involve the renal arteries. Evidence shows that patients with cold perfusion have superior survival and recovery rates, but none of the adjuncts clearly prevent acute renal failure. The current mortality rates associated with postoperative renal failure remain high, and the pursuit of the optimal method of renal protection is a top priority.