Normothermic Cardiopulmonary Bypass and Myocardial Cardioplegic Protection for Neonatal Arterial Switch Operation

Objective: Hypothermic cardiopulmonary bypass (CPB) associated with cold myocardial protection is commonly used to perform neonatal cardiac surgery. Hypothermia is usually chosen to preserve the brain in case of failure of oxygen delivery whatever it may result from. Nowadays, there is a growing number of evidence demonstrating that hypothermia induces deleterious effects, which may culminate in organ dysfunctions. In 2001, we started a protocol where the heart and the body were no longer cooled, in all the procedures, including the arterial switch operation (ASO), except those with aortic arch reconstruction.

Methods: Because data on the neonatal arterial switch operation were prospectively gathered in our unit (and included fine biochemical analysis of myocardial damage), we have compared two consecutive populations of arterial switch operation to sort out the impact of normothermic CPB and normothermic cardioplegia.

Results: The results show that warm cardiopulmonary bypass associated with warm cardioplegia is feasible for ASO, and that most of the operative data are similar to hypothermic bypass, none are worse. Among the postoperative data, the cardiac troponin I (cTnI) time course showed significantly lower values in the normothermic group after 24h (4.46ngml(-1) vs 6.17ngml(-1) (p=0.027)), time to extubation is improved (32+/-26h vs 70+/-69h (p=0.02)) and there is a trend to reduce the ICU length of stay (3.5+/-1.5 days vs 5.6+/-3.9 days (p=0.08)), and consequently the cost of surgery.

Conclusion: Normothermic cardiopulmonary bypass is feasible for ASO and seems to allow a faster recovery time.