Abstract 1792: Quantification of Cerebral Protection During Selective Cerebral Perfusion in Complex Cardiac Surgery
Objective Aim of this study was to evaluate the potential for cerebral protection using different modes of selective cerebral perfusion (SCP) during correction of complex congenital cardiac defects.
Methods 15 piglets (7–10kg, age 3– 4 weeks) received SCP via the right common carotid artery during extracorporeal circulation at 25°C for 90 min of cardioplegic cardiac arrest. Regular brain perfusion (1 ml/g/min.), moderate hypoperfusion (0.5 ml/g/min) and extensive hypoperfusion (0.25 ml/g/min) were evaluated. Clinical parameters and tissue oxygenation index (TOI) were registered online until three hours of reperfusion. HE staining and immunohistological analyses for heat shock protein (HSP) 70, apoptosis inducing factor (AIF) and nitrotyrosine (NO-Tyr) were performed on sections of the hippocampus.
Results Intracranial pressure remained stable throughout the study and there was no tissue edema. Hemodynamic parameters, blood gas and lactate measurements were within the normal range until the end of the study. Extensive hypoperfusion led to a moderate reduction in TOI and a significant increase in HSP70 immunopositivity. AIF immunopositive nuclei were present in 23.5% after regular perfusion, in 37.6% after moderate and in 49.5% after extensive hypoperfusion. NO-Tyr levels were 7.1±2.7 at regular cerebral perfusion, 8.3±2.9 at moderate hypoperfusion (p=n.s.) and 15±5.8 at extensive hypoperfusion (p<0.05).
Conclusions Unilateral selective cerebral perfusion is a safe concept when using regular perfusion as well as moderate hypoperfusion. Extensive hypoperfusion (25% of regular blood flow) is associated with increased cerebral ischemia.