OBJECTIVES:Experience regarding warm blood cardioplegia according to Calafiore results from its broad use in adult patients. In this experimental study, tepid (28°C) modified full blood cardioplegia (MBC) was adopted for paediatric use and compared with cold crystalloid cardioplegia (CCC).METHODS:Twenty male piglets (mean weight: 11.1 ± 1.0 kg) were operated on cardiopulmonary bypass (CPB) in moderate hypothermia (28°C) and randomized to MBC (n = 8) or CCC (n = 12) for 60 min aortic cross-clamping. Blood levels of myocardial proteins [N-terminal pro-brain natriuretic peptide (NT-pro-BNP), myoglobin, creatine kinase type MB and troponin-I] were investigated at the beginning of the experiment and after CPB. Haemodynamic measurements included thermodilution and conductance-catheter technique inserted through the left ventricle-apex. Pressure-volume loop analysis was performed with dobutamine-stress test and inflow occlusion, enabling preload independent evaluation of myocardial performance. Changes of measured data post-CPB were calculated in relation to baseline-levels (%).RESULTS:Baseline and operative data in both groups were similar. During the experiment, cardiac markers showed no significant variations between groups. Pressure-volume loop analysis during stress test revealed a significantly higher preload independent contractility (slope of end-systolic pressure-volume relation: Ees) with MBC compared with CCC (MBC: 123 ± 35% [confidence interval (CI95): 93-153] vs CCC: 78 ± 34% [CI95: 54-102]; P = 0.042), whereas cardiac output was not significantly different between groups {MBC: 122 ± 16% [95% confidence interval (CI95): 109-135] vs CCC: 105 ± 17% [CI95: 93-116]; P = 0.069}.CONCLUSION:This randomized animal study proves feasibility and safety of MBC for paediatric use. Haemodynamic evaluation and cardiac markers did not show inferiority to standard CCC. Moreover, MBC seems to be associated with superior contractility post bypass, which encourages us to use MBC in paediatric patients in the near future.

Einleitung: Die Blutkardioplegie nach Calafiore findet bisher in der Kinderherzchirurgie noch keine Anwendung. Wir postulierten geringere Elektrolytverschiebungen durch eine für Kinderherzen modifizierte Form der Blutkardioplegie nach Calafiore (MBC) im Vergleich zur kristalloiden Kardioplegielösung (CCC).

Background. Selective myocardial perfusion enables repair of congenital aortic arch obstruction without cardiac arrest. This study was inspired by the lack of prospective controlled studies of the beating heart (BH) technique compared with cold crystalloid cardioplegia (CC) regarding effects on myocardial performance, ischemic damage, and serum electrolyte levels.Methods. In a prospective study, 20 male piglets weighing 11.1 +/- 1.3 kg were operated on using cardiopulmonary bypass (CPB) and underwent 60 minutes of aortic cross-clamping. According to prospective randomization, myocardial protection included either a BH modification with selective myocardial perfusion using an individual roller pump or CC. Hemodynamic performance was evaluated by a conductance catheter technique before and after CPB and calculated in relation to baseline levels. Laboratory analysis included blood levels of troponin T and serum electrolytes.Results. Eighteen piglets entered analysis. There were significantly higher slopes of end-systolic pressure-volume relations (168% +/- 92% versus 89% +/- 16%; p = 0.046) and preload-recruitable stroke work (PRSW) (139% +/- 37% versus 103% +/- 31%; p = 0.040) in BHpiglets comparedwith those who underwent CC. Laboratory analysis during reperfusion revealed higher levels of troponin T (1.31 +/- 0.28 ng/mL versus 0.49 +/- 0.17 ng/mL; p < 0.01) andsodium(131 +/- 4 mmol/L versus 120 +/- 8mmol/L; p = 0.003) and lower levels of potassium(4.8 +/- 0.4mmol/L versus 6.4 +/- 1.0mmol/L; p = 0.001) with BH compared with CC, whereas no significant differences were calculated at the end of the experiment.Conclusions. The BH technique is associated with improved contractility compared with standard CC. There is comparable ischemic damage in both groups, with an earlier rise in blood levels of troponin T after BH and more fluctuation of serum electrolytes with CC. Evidence of ischemic changes should dissuade one from using the BH technique imprudently. (C) 2015 by The Society of Thoracic Surgeons

Objectives: Repair of congenital aortic arch obstruction can be performed on the beating heart (BH) with selective myocardial perfusion. We hypothesized an improved postoperative cardiac performance using the BH-technique compared to crystalloid cardioplegia (CC) in a piglet model.

Objectives: Aortic arch repair on the beating heart is well established in the clinical routine of congenital cardiac surgery. However, the method lacks validation in an animal model proving its superiority compared to the standard cardioplegia technique.