Visceral ischemia and organ dysfunction after thoracoabdominal aortic aneurysm repair. A clinical and cost analysis

Abstract

Objective: Repair of thoracoabdominal aortic aneurysms (TAAAs) is associated with significant postoperative morbidity and mortality. Reperfusion of acutely ischemic abdominal viscera in animals leads to release of multiple factors that cause local and distant organ damage, and similar phenomena occurring in humans after TAAA repair could contribute to the high morbidity/mortality and cost associated with this procedure.

Methods: Twenty-nine patients undergoing elective TAAA repair were studied prospectively. Preoperative organ dysfunction and intraoperative risk factors (cross-clamp time, blood loss, operative time) were assessed and compared with postoperative organ dysfunction (defined as: pulmonary, positive pressure ventilation for > 7 days; renal, increase in serum creatinine > 2.0 mg/dL over baseline; hepatic, lactate dehydrogenase > 500 international units and total bilirubin > 3.0 mg/dL or serum transaminase level > 200 international units; hematopoietic, platelet count > 50 K or leukocyte count > 4.5 K, mortality, and costs.

Results: No relationship between preoperative organ dysfunction, blood loss, or operative time and postoperative organ dysfunction or mortality was seen; however, cross-clamp times > 40 minutes were associated with a significantly greater incidence of pulmonary (59%), renal (47%), hepatic (35%), and hematopoietic (47%) dysfunction. In addition, multiple-organ dysfunction (> 2 organ systems) was more common after > 40 minutes of visceral ischemia and led to significantly greater overall hospital ($88,465 + $76,155 vs. $41,782 + $31,244) and intensive care unit ($26,726 + $28,256 vs. $11,234 + $12,146) costs (p < 0.01, Mann-Whitney U test). Mortality associated with leukopenia was 67% compared with 4% without leukopenia (p < 0.01).

Conclusion: Increasing durations of acute visceral ischemia led to significant multiple organ dysfunction after TAAA repair. Methods of limiting visceral ischemia or the systemic effects of visceral ischemia may decrease both the morbidity and mortality and the overall hospital cost associated with this procedure.