Thoraco-abdominal normothermic regional perfusion does not restore cerebral blood flow or electrical activity despite collateral supra-aortic blood flow in a porcine model.

Background: It is unknown whether ligation of supra-aortic vessels during thoraco-abdominal normothermic regional perfusion (TA-NRP) can prevent postmortem brain function, ensuring the permanence of death. Our objective was to determine if ligation of the supra-aortic vessels during TA-NRP prevents resumption of intracranial blood flow, brain electrical activity and clinical brain function in a porcine model of organ donation after circulatory arrest. Methods: Neuromonitoring was performed in 9 porcine experiments, in which supra-aortic vessels were ligated. Results: During TA-NRP and organ procurement, no motor reaction to pain, spontaneous ventilation, eye movement or change in pupillary function were observed. Angiography demonstrated absence of supra-aortic blood flow in 4 (44%) experiments and delayed, discrete and transient supra-aortic extracranial opacification in 5 (56%) experiments. No intracranial blood flow was observed. All electroencephalograms demonstrated absent brain electrical activity. Conclusion: In this porcine model, occlusion of the supra-aortic vessels during TA-NRP did not restore post-mortem cerebral blood flow or electrical activity and is in adequation with the permanence of death.