Type IV thoracoabdominal aneurysm repair: predictors of postoperative mortality, spinal cord injury, and acute intestinal ischemia.

Our purpose was to identify preoperative and intraoperative predictors of early mortality, spinal cord injury, or acute intestinal ischemia after repair of type IV thoracoabdominal aneurysm (TAA IV) as a basis for optimizing surgical indications and techniques. From January 1991 to June 2006 we operated on 171 patients for TAA IV. There were 149 men (87.1%) and 22 women (12.9%), with a mean age of 65.0 +/- 10.9 years (range 23-82). The underlying etiology was degenerative aneurysmal disease in 143 patients (83.6%). Twenty-two patients (12.8%) underwent emergent operation. Comorbidity included coronary disease in 72 patients (45.6%) including 39 who had undergone a revascularization procedure, arterial hypertension in 121 (70.1%), chronic obstructive pulmonary disease in 81 (47.4%), and chronic kidney insufficiency in 58 (33.9%). Seventy-six patients (44.4%) presented concurrent lesions involving at least one visceral artery. Spinal cord arteriography was performed in 91 patients (53.2%). In 25 cases (27.5%) arteriographic findings demonstrated the need for revascularization of the Adamkiewicz artery due to location of the ostium at or below the T12 level. Repair was carried out with cross-clamping only in 160 cases (93.6%). Partial cardiopulmonary bypass was used in 11 patients (6.4%). A total of 23 patients (13.4%) died postoperatively. The cause of death was acute intestinal ischemia in nine cases, multiple organ failure in seven, coagulation disorder in three, cardiac complications in two, and stroke in two. Spinal cord injury occurred in eight patients (4.7%) including two who died. According to univariate analysis, the significant predictors of early death were age over 70 years, degenerative aneurysmal disease, coronary artery disease, chronic renal insufficiency or visceral artery lesions, operator, duration of intestinal ischemia and use of a "complex" surgical technique. Although the only significant predictor of spinal cord injury was duration of digestive ischemia, an almost significant trend (p < 0.1) was observed for coronary artery disease, coronary bypass, and renal insufficiency. The significant predictors of acute intestinal ischemia were kidney insufficiency and visceral artery lesions, but coronary artery disease and previous coronary bypass were almost significant (p = 0.06). Frequent association of TAA IV with arteriosclerotic disease in elderly patients presenting coronary artery disease and chronic kidney insufficiency partly explains why early postoperative mortality remains high. The incidence of spinal cord injury suggests that preoperative spinal cord arteriography is mandatory for prevention. The frequency of intestinal ischemia is more problematic, but a better understanding of the underlying mechanism should enable development of preventive strategies.