Application comparison of paediatric myocardial protection procedures in arterial switch surgery

Reliable myocardial protection is essential for a good outcome after arterial switch operation. We evaluated 56 neonates with arterial switch operation in this retrospective study. Three types of cardioplegia were used: antegrade Custodiol® (CCC) = 22, antegrade Custodiol® plus paediatric microplegia (mix) = 14, and antegrade plus retrograde intermittently paediatric microplegia (blood) = 20. We evaluated the extent of myocardial injury using troponin I, Creatine kinase (CK), CK-MB (CK in myocardial cells) and vasoactive inotrope score (VIS), immediately- and the first postoperative day, as well as outcome parameters. A statistical analysis was conducted using multiple linear regression, with adjustments made for the RACHS score and ischemia time, at a significance level of 5%. Preoperative data were comparable between the three groups. Aortic cross clamp time was significantly different between the three groups (CCC: 115 ± 26 min: mix: 162 ± 35 min: blood: 153 ± 31 min). We found significantly lower troponin I release in the blood group 14 ng/mL [CI95 10; 18] versus CCC group 36 ng/mL [CI95 27; 48] and versus mix group 27 ng/mL [CI95 19; 38]; troponin I 24 h blood group 8 ng/mL [CI95 6; 11] versus CCC group 14 ng/mL [CI95 10; 19]. No significant differences were found in CK, CK-MB, VIS, as well as in outcome parameters 30-day mortality, ventilation time, hospital stay or ECMO implantation. Intermittent paediatric microplegia led to a significantly lower release of troponin I, despite significantly longer ischemia times than after application of Custodiol®. Paediatric microplegia can be safely performed in neonates and also offers the advantage of miniaturization of the Cardiopulmonary bypass setup.