Postoperative brain complications following retrograde cerebral perfusion

This study was undertaken to investigate the neurological risk factors associated with the retrograde cerebral perfusion (RCP) technique, by examining the relationship between intraoperative parameters and post-operative brain complications. A total of 12 patients who underwent surgery for thoracic aortic aneurysms using the RCP technique were included in this study. Profound hypothermia was induced through cardiopulmonary bypass which was established with a femoral arterial cannula and bicaval return. During RCP, a venous drainage cannula from the superior vena cava (SVC) was switched over to the arterial return circuit, and oxygenated blood was retrogradely infused through the SVC. The perfusion flow rate was maintained at 273 +/- 113 ml/min and the SVC pressure was maintained at 15 +/- 6 mmHg. The RCP time was 68 +/- 27 min with a range of 27-130 min, and the lowest rectal temperature was 16 +/- 1 degrees C. The total elapsed time until emergence from anesthesia after the operation was 12 +/- 6 h. The operation time correlated with the awakening time (r = 0.729, P = 0.0088). Longer RCP times of up to 101 and 130 min tended to result in post-operative brain damage. The lowest rectal temperature also correlated with the awakening time (r = 0.697, P = 0.0149), and an inverse correlation between the SVC pressure and the awakening time was observed (r = -0. 727, P = 0.0091). These findings demonstrate the importance of reducing both the RCP and operation times to decrease the incidence of brain damage. If carried out under optimal conditions, including perfusion pressure and brain temperature, RCP could be marginally prolonged safely without causing major neurological complications.