Moderate versus deep hypothermia for arterial switch operation.

ABSTRACT

BACKGROUND: We evaluated the impact of moderate versus deep intraoperative hypothermia on postoperative morbidity in patients receiving a standard arterial switch operation (ASO). METHODS: 71 newborns underwent ASO from 9/98 onwards. Patients were operated using moderate hypothermia (M, 24 degrees C to 30 degrees C, n=21) or deep hypothermia (D, 16-22 degrees C, n=50). Mean patient age was 9.5 (M) versus 10 (D) days, body weight 3.6+/-0.7 (M) versus 3.8+/-0.9 kg (D), P=n. s. Coronary anatomy was complex in 9.5% (M) versus 16% (D) of patients; additional VSD was present in 23.8 (M) versus 38% (D) of the patients, respectively. Mean follow-up is 2.3+/-1.6 years. RESULTS: Intraoperative rectal temperature was 25+/-2 degrees C (M) and 19+/-2 degrees C (D). Cross-clamping time was 95+/-24 (M) versus 108+/-31 min (D), P=n. s. Conventional ultrafiltration was performed at 114+/-46 (M) versus 129+/-69 ml/kg (D), P=n. s. One patient (D) with complex anatomy suffered myocardial ischemia required ECMO support and died. In-hospital mortality was 1.4%. All other patients were safely weaned from extracorporeal circulation with moderate inotropic support. Secondary chest closure was performed in 33% (M) versus 54 % (D) of the patients. Patients were extubated after 7.4 (M) versus 6 (D) days. There was no renal failure and no other serious complications. CONCLUSIONS: ASO can be safely performed using moderate hypothermia, even with complex anatomy, leading to comparatively good results compared to a conventional approach.