Active cooling during open repair of thoraco-abdominal aortic aneurysms improves outcome

Objective: Evaluate impact of active cooling with partial cardiopulmonary b ypass (CPB) and low systemic heparinization during open repair of thoracoab dominal aortic aneurysms. Methods: Prospective analysis of 100 consecutive patients undergoing surgical repair of thoracoabdominal aortic aneurysms. P artial CPB and normothermic (36 degreesC) or hypothermic (29 degreesC) perf usion was selected in accordance to the surgeons preference. In the hypothe rmic group, aortic cross clamp was applied when the target temperature of t he venous blood was achieved and rewarming was started after declamping. Re sults: 52/100 patients (62.2 +/- 10.9 years) received normothermic and 48/1 00 patients hypothermic perfusion (63.8 +/- 10.6 years: NS). Emergent proce dures accounted for 18/52 (35%) with normothermic vs. 21/48 (44%: NS) with hypothermia. The number of aortic segments (eight = maximum including arch and bifurcation) replaced was 3.9 +/- 1.5 with normothermia vs. 4.1 +/- 1.5 with hypothermia (NS); Crawford type II aneurysms accounted for 21/52 pati ents (40%) for normothermia vs. 20/48 (42%:NS) for hypothermia. Total clamp time was 38 +/- 21 min with normothermia vs. 47 +/- 28 min with hypothermi a (P = 0.05). Pump time was 55 +/- 28 min with normothermia vs. 84 +/- 34 m in with hypothermia (P = 0.001). Mortality at 30 days was 8/52 patients (15 %) with normothermia vs. 2/48 (4%) with hypothermia (P = 0.06; odds ratio = 4.1). Parapareses/plegias occurred in 4/52 patients (8%) with normothermia vs. 4/48 (8%) with hypothermia (NS). Revisions for bleeding were required in 4/52 patients (8%) with normothermia vs. 2/48 patients (4%) with hypothe rmia (P = 0.38). Revisions for distal vascular problems were necessary in 5 /52 patients (10%) with normothermia vs. 2/48 (4%) with hypothermia (P = 0. 25). Freedom from death, paraplegia, and surgical revision was 89.9% with n ormothermia vs. 94.8% with hypothermia (P = 0.04; odds ratio 2.0). Conclusi ons: Active cooling during repair of thoracoabdominal aortic aneurysms allo ws for longer cross-clamp times, more complex repairs and improves outcome. (C) 2001 Published by Elsevier Science B.V. All rights reserved.