Implementation and design of customized ex vivo machine perfusion. Analysis of its first results

Abstract

The lack of organs available for transplantation is a global problem. The high mortality rates on the waiting list and the high number of discarded livers are reasons to develop new tools in the preservation and transplantation process.New tools should also be available for low-income countries. This article reports the development of customized normothermic machine perfusion (NMP). An ex vivo dual perfusion machine was designed, composed of a common reservoir organ box (CRO), a centrifugal pump (portal system, low pressure), and a roller pump (arterial system, high pressure). Porcine livers (n = 5) were perfused with an oxygenated normothermic (37℃) strategy for 3 hours. Hemodynamic variables, metabolic parameters, and bile production during preservation were analyzed. Arterial and portal flow remain stable during perfusion. Total bilirubin production was 11.25 mL (4-14.5) at 180 minutes. The median pH value reached 7.32 (7.25-7.4) at 180 minutes. Lactate values decreased progressively to normalization at 120 minutes. This perfusion setup was stable and able to maintain the metabolic activity of a liver graft in a porcine animal model. Design and initial results from this customized NMP are promising for a future clinical application in low-income countries.

Customized normothermic machine perfusion decreases ischemia–reperfusion injury compared with static cold storage in a porcine model of liver transplantation

“…The porcine model was chosen mainly due to technical reasons and the translational opportunities that might provide. We chose a 3‐h period for NMP, as we published recently, 16 since it is the minimal time frame, we found for lactate normalization and stable bile production, which are both good markers of hepatic function. We did a 5‐h postoperative follow‐up for a minimal time frame to evaluate liver function and IRI markers, in accordance with the authorization of the local Ethical Committee of Animal Welfare, mainly due to animal welfare constraints.…”

“…The donation procedure was carried out in the same way in all animals, as previously described 16 . As vascular access to the liver, portal vein and abdominal aorta (and hepatic artery) were preserved.…”

“…The donation procedure was carried out in the same way in all animals, as previously described. 16 As vascular access to the liver, portal vein and abdominal aorta (and hepatic artery) were preserved. During organ procurement, 30% of the total circulating volume (60 ml/kg, 650-850 ml) was collected from a central venous line.…”

“…Our customized machine perfusion integrates three main structures that have been extensively described previously. 16 A common reservoir, a centrifugal pump (CP), and a roller pump (RP). Briefly, perfusate is taken from the common reservoir by the CP.…”

“…Since this is the minimal time frame that we found for lactate normalization and stable bile production as we published previously. 16…”