Retrograde cerebral perfusion through a superior vena caval cannula protects the brain

Retrograde cerebral perfusion through a superior vena caval cannula is a new technique for protecting the brain during aortic arch operations, In mongrel dogo (n = 10; 13 to 15 kg) we have performed retrograde cerebral perfusion (300 mL/min) by infusing blood through a superior vena caval cannula with aortic and inferior vena caval drainage. We have measurer the cerebral tissue blood flow, oxygen consumption, and carbon dioxide exudation during retrograde cerebral perfusion at normothermia (NT, 37 ° C) and hypothermia (HT, 20 ° C) and have compared these values with values obtained in dogs during cardiopulmonary bypass (1,200 mL/min). Cerebral tissue blood flow was measured by the hydrogen clearance method. During retrograde cerebral perfusion about 20% of the superior vena caval perfusate was returned through the aorta and the rest drained from the inferior vena cava. Cerebral vascular resistance during retrograde cerebral perfusion was lower than that during cardiopulmonary bypass (NT, 63.8 ± 52.5 versus 126.9 ±58.4; HT, 28.4 ± 32.8 versus 69.5 ± 28.7 × 10³ dynes · s · cm^-5). Retrograde cerebral perfusion provided half the cerebral tissue blood flow of cardiopulmonary bypass (NT, 14.7 ± 6.4 versus 34.3 ± 7.8; HT, 17.6 ±5.6 versus 37.2 ± 10.6 mL/min). Retrograde cerebral perfusion also provided a third of the oxygen (NT, 4.4 ±2.1 versus 12.3 ± 7.1; HT, 1.4 ± 0.8 versus 4.2 ± 1.3 mL/min) and discharged 20% of the carbon dioxide (NT, 0.24 ± 0.08 versus 1.19 ± 0.58; HT, 0.15 ± 0.06 versus 0.51 ± 0.17 mmol/mm) when compared with cardiopulmonary bypass. Retrograde cerebral perfusion may reduce ischemic damage during interruption of cerebral blood flow.