Early postoperative effects of the hypothermia level during hypothermic circulatory arrest in patients with ascending aortic aneurysm

Abstract

Aim. To compare the effectiveness and safety of ascending aortic hemiarch replacement performed during hypothermic circulatory arrest with different temperature regimens.Material and methods. The study included 104 patients with ascending aortic aneurysm, who underwent ascending aortic hemiarch replacement under hypothermic circulatory arrest and antegrade cerebral perfusion. Depending on the temperature regimen, all patients were divided into two comparable groups: group 1 (n=28) — patients operated on under mild hypothermia (29-31oС), group 2 (n=76) — patients operated on under moderate hypothermia (25-28oC).Results. Comparative analysis of intraoperative data between groups of patients with mild and moderate hypothermia revealed a significant difference in the duration of cardiopulmonary bypass (111 [97; 135] min vs 125 [108.5; 170] min, p=0,031) and surgery (240 [210; 270 ] min vs 275 [240; 330] min, p=0,003). In the early postoperative period, the best results were also obtained in patients of mild hypothermia group. In these patients, compared with moderate hypothermia group, there was a lower frequency of reoperation due to bleeding (3,5% vs 5,2%, p=0,572), a decrease in transfused fresh frozen plasma volume (2 [2; 4] vs 4 [2; 4], p=0,03), a decrease in the ventilatory support duration (10 [7; 16] hours vs 18 [10; 24] hours, p=0,002), as well as a bed-day decrease in intensive care unit (2 [2; 3] and 3 [2; 4] days, p=0,005). No neurologic deficit was found in any of the patients. In-hospital mortality had no significant intergroup differences (p=0,541).Conclusion. An increase in the temperature regimen during the ascending aortic hemiarch replacement performed under hypothermic circulatory arrest is relatively safe in relation to early postoperative complications. Mild hypothermia does not increase early postoperative surgical risks compared to moderate hypothermia.