Normothermic regional perfusion in a DCD-III scenario: first experience

I.J. Schurink, J.E. de Haan, J.I. Erdmann, V.A.L. Huurman, J.N.M. IJzermans, J. de Jonge, W.G. Polak

Thursday 15 march 2018

15:30 - 15:35h at Willem Burger Foyer

Categories: Donation, Session (poster)

Parallel session: Poster session 5: Donation

Due to the tremendous organ shortage, marginal grafts like grafts of donors after circulatory death (DCD) are used for liver transplantation. DCD grafts have higher complication rates, in particularly biliary complications. One of the most important factors of this higher complication rate is the donor warm ischemia time (DWIT). Normothermic regional perfusion (NRP) is a novel technique to abolish donor warm ischemia as soon as possible, by restoring the circulation with oxygenated blood in the isolated abdominal compartment in the donor. In this study we describe our first experiences with NRP.

In a pig DCD model, 2 hours of NRP was performed after a DWIT of 15, 30 or 45 min. To evaluate the quality of the liver, bile and blood was collected every 30 min in order to determine ALAT, bilirubin, lactate and biliary pH. Furthermore, the blood flow in the hepatic artery and portal vein was measured during NRP.

So far, 3 of 7 experiments have been done, including 15, 30 and 45 min of DWIT. Typical pump flow was 0.9-1.2 L/min, generating a physiological blood pressure of 120 mmHg. NRP restored hepatic arterial blood flow from 78 to 166 and portal blood flow from 460 to 600 ml/min. In all livers ALAT levels improved during NRP, with the biggest decrease in the 15 min DWIT pig. During NRP, the total bile production showed an inverse relation with the DWIT, ranging from 13.5 ml bile in the 15 minutes DWIT pig to 2 ml in 45 min DWIT. During the NRP, the acidity of bile initially increased, showing HCO3 excretion failure of cholangiocytes, but after 60-90 minutes biliary pH was restored for livers with 15 and 30 min DWIT. In 45 min of DWIT, pH was however further decreased. Interestingly, we did not find lactate clearance, as described in literature in the 15 and 30 minutes DWIT, Starting arterial lactate of 9.5mmol/l remained stable during NRP with limited extraction over the liver. In the 45 min DWIT, lactate increased to 180% of starting value. Histology of the liver and viability of the bile duct will be shown at congress.

In conclusion, the first experience with the NRP technique was successful, with no technical difficulties during establishment of the NRP circuit. Liver quality was assessable with transaminase levels and monitoring of bile production and acidity. NRP is a promising strategy to recover DCD donor livers from damage inflicted during DWIT. An human implementation strategy for DCD-III cases is being prepared by the stand-alone retrieval team West.