Influence of moderate hypothermic circulatory arrest on outcome in patients undergoing elective replacement of thoracic aorta

BACKGROUND: The ideal technique of cerebral protection in the surgical operation of the ascending aorta.is currently controversial. The current analysis evaluates the influence of moderate hypothermic circulatory arrest (MHCA) on elective replacement of the ascending aorta. METHODS: The study included 905 consecutive patients between 2001 and 2015, who underwent replacement of ascending aorta in MHCA. Patients were divided according to the postoperative 30-day mortality into survivor und non-survivor group. RESULTS: The average age was 66.5±11.1 in survivors vs. 70.0±10.5 years in non-survivors (P=0.057). The survivor group had a significantly lower Euro-SCORE II than non-survivors [4.0% (2.3, 6.6) vs. 9.5% (4.8, 20.9); P<0.001)]. The incidence of coronary heart disease (38.0% vs. 58.3%; P=0.022) and chronic renal failure (10.0% vs. 33.3%, P<0.001 was significantly higher in non-survivors. Intraoperatively, the cardiopulmonary bypass time [140 min (112, 185) vs. 194 min (164, 271); P<0.001] and cross-clamping time [91 min (64, 124) vs.119 min (94, 157); P<0.001] were significantly longer in non-survivors. However, the MHCA time was similar in both groups with statistical significance (P=0.023). Postoperatively, re-exploration due to bleeding was highly significant in non-survivors (5.4% vs. 33.3%; P<0.001) with a higher incidence of stroke (4.6% vs. 33.3%; P<0.001). The duration of mechanical ventilation was significantly shorter in survivors than in non-survivors [17 h (12, 26) vs. 147 h (49, 337); P<0.001] with a lower incidence of pulmonary infection (6.0% vs.16.7%; P=0.023). The multivariable logistic regression analysis showed age, female gender, aortic aneurysm, additional CABG, total arch replacement and cardiopulmonary bypass time were independent risk factors for 30-day mortality. CONCLUSIONS: The acceptable morbidity and mortality rates show that MHCA can be considered as a safe technique for cerebral protection in surgical replacement of thoracic aorta.