Evaluation of Cerebral Blood Pressure During Normothermic Regional Perfusion

Normothermic regional perfusion (NRP) is an effective method for recovering donation after circulatory death (DCD) organs. However, concerns remain that NRP may allow unintended cerebral perfusion despite clamping of the head vessels. This study aims to evaluate cerebral blood pressure as a surrogate for flow during NRP. After withdrawal of life-sustaining treatment (WLST) and a 5 minute standoff period, NRP was initiated. Pressures were obtained in the left common carotid artery and innominate artery at 30 and 60 minutes, alongside perfusion flow and mean arterial pressure. Seven donors underwent thoracoabdominal NRP and one underwent abdominal NRP. Average time from WLST to asystole was 20.0 ± 7.2 minutes and from declaration of death to initiation of perfusion was 10.86 ± 3.5 minutes. Average NRP duration was 92.1 ± 27.6 minutes. Post-NRP initiation pressures ranged from 4 to 25 mm Hg. These pressures were consistent with mean circulatory pressure filling pressures, reflecting a nonflow state. Our findings suggest that NRP does not result in appreciable cerebral blood pressure or effective intracranial perfusion following clamping of brachiocephalic vessels. These data support the physiological validity of current NRP protocols in preventing unintended cerebral reperfusion.