Non-invasive measurement of hepatic oxygenation by an oxygen electrode in human orthotopic liver transplantation

Precise evaluation of graft reperfusion is difficult in clinical liver tran splantation. The oxygen electrode (OE) is a novel technique to detect blood flow indirectly by measuring the quantity of oxygen which can diffuse from the hepatic tissue to the surface electrode. Application of the surface OE does not influence the liver blood flow or parenchymal perfusion. Adequate graft oxygenation is essential to the outcome of organ transplantation and has not previously been analysed intra-operatively in liver transplant rec ipients. The OE was applied to the surface of the graft intra-operatively i n 22 human liver grafts after restoring portal vein and hepatic artery infl ow. OE readings were compared with liver blood flow using an electromagneti c flowmeter (EMF). Intra-operative haemodynamics and donor organ parameters known to influence graft function were correlated with the OE readings. Th ere was a significant correlation (r=0.89; p<0.001, n=14) between tissue ox ygenation using the OE and total liver blood flow measured by EMF, The tiss ue oxygenation measurements were reproducible with a coefficient of variati on of 5%, The hepatic tissue oxygenation increased significantly from basel ine following venous reperfusion of the graft (282+/-23 vs 3107+/-288 (+/-S E) nA, p<0.001), Hepatic arterial revascularisation resulted in a significa nt (p<0.001) increase of 41+/-7% in liver oxygen perfusion. There was signi ficant negative correlation (r=0.80, p<0.001, n=22) between cold ischaemic time and graft tissue oxygenation. The OE provides a reliable, cheap and no n-invasive method of monitoring liver graft oxygenation and perfusion durin g transplantation. (C) 2000 IPEM. Published by Elsevier Science Ltd, All ri ghts reserved.