REGIONAL BLOOD-FLOW DURING PULSATILE CARDIOPULMONARY BYPASS AND AFTERCIRCULATORY ARREST IN AN INFANT MODEL

Background. Pulsatile perfusion systems have been proposed as a means of improving end-organ perfusion during and after cardiopulmonary bypa ss. Few attempts have been made to study this issue in an infant model . Methods. Neonatal piglets were subjected to nonpulsatile (n = 6) or pulsatile (n = 7) cardiopulmonary bypass and 60 minutes of circulatory arrest. Cerebral, renal, and myocardial blood flow measurements were obtained at baseline, on bypass before and after circulatory arrest, a nd after bypass. Results. Cerebral blood flow did not differ between g roups at any time and was diminished equally in both groups after circ ulatory arrest. Renal blood flow was diminished in both groups during bypass but was significantly better in the pulsatile group than in the nonpulsatile group prior to, but not after, Circulatory arrest. Myoca rdial blood now was maintained at or above baseline in the pulsatile g roup throughout the study, but in the nonpulsatile group, it was signi ficantly lower than baseline during CPB prior to circulatory arrest an d lower compared with baseline and with the pulsatile group 60 minutes after CPB.Conclusions. Pulsatile bypass does not improve recovery of cerebral blood flow after circulatory arrest, may improve renal perfus ion during bypass but does not improve its recovery after ischemia, an d may have beneficial effects on myocardial blood flow during bypass a nd after ischemia compared with nonpulsatile bypass in this infant mod el. (C) 1997 by The Society of Thoracic Surgeons.