Novel short-term hypothermic oxygenated perfusion (HOPE) system prevents injury in rat liver graft from non-heart beating donor

Abstract

Objective: To assess a machine perfusion system in rescuing liver grafts from non-heart-beating donors (NHBD).

Summary background data: The introduction of extracorporeal liver perfusion systems in the clinical routine depends on feasibility. Conceivably, perfusion could be performed during recipient preparation. We investigated whether a novel rat liver machine perfusion applied after in situ ischemia and cold storage can rescue NHBD liver grafts.

Methods: We induced cardiac arrest in male Brown Norway rats by phrenotomy and ligation of the subcardial aorta. We studied 2 experimental groups: 45 minutes of warm in situ ischemia + 5 hours cold storage versus 45 minutes of warm in situ ischemia + 5 hours cold storage followed by 1 hour hypothermic oxygenated extracorporeal perfusion (HOPE). In both groups, livers were reperfused in a closed sanguineous isolated liver perfusion device for 3 hours at 37 degrees C. To test the benefit of HOPE on survival, we performed orthotopic liver transplantation in both experimental groups.

Results: After cold storage and reperfusion, NHBD livers showed necrosis of hepatocytes, increased release of AST, and decreased bile flow. HOPE improved NHBD livers significantly with a reduction of necrosis, less AST release, and increased bile flow. ATP was severely depleted in cold-stored NHBD livers but restored in livers treated by HOPE. After orthotopic liver transplantation, grafts treated by HOPE demonstrated a significant extension on animal survival.

Conclusions: We demonstrate a beneficial effect of HOPE by preventing reperfusion injury in a clinically relevant NHBD model.

Figures

FIGURE 1. Fresh resected reperfused livers () showed no significant AST release during 3 hours normothermic ex vivo reperfusion. Livers exposed to 45 minutes of warm ischemia + 5 hours cold storage (▴) showed significantly increased AST release, which could be prevented by HOPE before reperfusion (▪).

FIGURE 2. Bile flow was high in fresh resected livers () and severely decreased in livers after 45 minutes of warm ischemia + 5 hours cold storage (▴). HOPE resulted in significantly improvement of bile flow (▪).

FIGURE 3. A, Fresh resected livers showed normal gross appearance after 3 hours reperfusion on the IPRL. B, Histologic samples confirmed no necrosis of fresh resected reperfused livers. C, Livers after 45 minutes of warm ischemia + 5 hours cold storage showed macroscopically inhomogeneous perfusion pattern. D, Histologic samples showed multiple necrosis after reperfusion (45 minutes of warm ischemia + 5 hours cold storage). E, Livers treated by HOPE after 45 minutes of warm ischemia + 5 hours cold storage appeared macroscopically similar like fresh resected livers. F, Histologic samples demonstrated no necrosis after reperfusion (45 minutes of warm ischemia + 5 hours cold storage + 1 hour HOPE).

FIGURE 4. Perfusate lactate degradation during reperfusion was not different between fresh resected livers () and livers after 45 minutes of warm ischemia + 5 hours cold storage if HOPE was performed before reperfusion (▪). In contrast, ischemic livers not treated by HOPE exhibited a high amount of lactate, which could not be degraded to physiologic levels during 3 hours of reperfusion (▴).

FIGURE 5. Hepatic oxygen uptake (HOU) was low and constant during reperfusion of fresh resected livers (). After 45 minutes of warm ischemia + 5 hours cold storage, oxygen consumption was significantly increased (▴). HOPE before reperfusion decreased hepatic oxygen uptake during reperfusion (▪).