Pre-retrieval reperfusion decreases cancer recurrence after rat ischemic liver graft transplantation.

BACKGROUND & AIMS Liver transplantation from marginal donors is associated with ischemia/reperfusion (I/R) lesions, which may increase the risk of post-transplant hepatocellular carcinoma (HCC) recurrence. Graft reperfusion prior to retrieval (as for extracorporeal membrane oxygenation--ECMO) can prevent I/R lesions. The impact of I/R on the risk of cancer recurrence was assessed on a syngeneic Fischer-rat liver transplantation model. METHODS HCC cells were injected into the vena porta of all recipients at the end of an orthotopic liver transplantation (OLT). Control donors were standard heart-beating, ischemic ones (ISC), underwent 10 min or 30 min inflow liver clamping prior to retrieval, and ischemic/reperfused (ISC/R) donors underwent 2h liver reperfusion after the clamping. RESULTS I/R lesions were confirmed in the ISC group, with the presence of endothelial and hepatocyte injury, and increased liver function tests. These lesions were in part reversed by the 2h reperfusion in the ISC/R group. HCC growth was higher in the 10 min and 30 min ISC recipients (p = 0.018 and 0.004 vs. control, as assessed by MRI difference between weeks one and two), and was prevented in the ISC/Rs (p = 0.04 and 0.01 vs. ISC). These observations were associated with a stronger pro-inflammatory cytokine profile in the ISC recipients only, and the expression of hypoxia and HCC growth-enhancer genes, including Hmox1, Hif1a and Serpine1. CONCLUSIONS This experiment suggests that ischemia/reperfusion lesions lead to an increased risk of post-transplant HCC recurrence and growth. This observation can be reversed by graft reperfusion prior to retrieval.