Hepatocyte growth factor and transforming growth factor beta1 contribute to regeneration of small-for-size liver graft immediately after transplantation

Hypoxia protects the liver from Small For Size Syndrome: A lesson learned from the associated liver partition and portal vein ligation for staged hepatectomy (ALPPS) procedure in rats

Portal hyperperfusion and "dearterialization" of the liver remnant are the main pathogenic mechanisms for Small For Size syndrome (SFSS). Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) induces rapid remnant hypertrophy. We hypothesized a similar increase in portal pressure/flow into the future liver remnant in ALPPS and SFSS-setting hepatectomies. In a rodent model, ALPPS was compared to SFSS-setting hepatectomy. We assessed mortality, remnant hypertrophy, hepatocyte proliferation, portal and hepatic artery flow, hypoxia-induced response, and liver sinusoidal morphology. SFSS-hepatectomy rats were subjected to local (hepatic artery ligation) or systemic (Dimethyloxalylglycine) hypoxia. ALLPS prevented mortality in SFSS-setting hepatectomies. Portal hyperperfusion per liver mass was similar in ALLPS and SFSS. Compared to SFSS, efficient arterial perfusion of the remnant was significantly lower in ALPPS causing pronounced hypoxia confirmed by pimonidazole immunostaining, activation of hypoxia sensors and upregulation of neo-angiogenic genes. Liver sinusoids, larger in ALPPS, collapsed in SFSS. Induction of hypoxia in SFSS reduced mortality. Hypoxia had no impact on hepatocyte proliferation but contributed to the integrity of sinusoidal morphology. ALPPS hemodynamically differ from SFSS by a much lower arterial flow in ALPPS's FLR. We show that the ensuing hypoxic response is essential for the function of the regenerating liver by preserving sinusoidal morphology.

Liver Transplantation in Asia: Past, Present and Future

With the technical advances and improvements in perioperative management and immunosuppressants, liver transplantation is the standard treatment for patients with end-stage liver diseases. In Asia, a shortage of deceased donor liver grafts is the universal problem to be faced with in all transplant centres. Many surgical innovations are then driven to counteract this problem. This review focuses on 3 issues that denote the development of liver transplantation in Asian countries. These include living donor liver transplantation (LDLT), split liver transplantation (SLT) and liver transplantation for hepatocellular carcinoma (HCC). Minimal graft weight, types of liver graft to donate and the inclusion of the middle hepatic vein with the graft are the main issues to be established in LDLT. The rapid growth and wide dissemination of LDLT has certainly alleviated the supply-and-demand problem of liver grafts in Asia. SLT is another attractive approach. Technical expertise, donor selection and graft allocation are the main determinants for its success. Liver transplantation plays a key role in the management of HCC in Asia. LDLT would be the main strategy in this aspect. The issue of extending the selection criteria for HCC patients for LDLT is still controversial. On the whole, future developments to increase the donor pool for the expanding recipient need in Asia would involve transplantation from non-heart beating donor and ABO incompatible transplantation.

Liver transplantation for hepatocellular carcinoma in Asia

Hepatocellular carcinoma (HCC) is a leading cause of cancer death, particularly in Asia where the major etiology, chronic hepatitis B virus infection, is endemic. The tumor frequently develops in a background of cirrhosis, and liver transplantation offers a chance to cure both the tumor and the underlying cirrhosis. The Milan criteria based on tumor size and number as an estimate of tumor burden are conventionally the gold standard in determining eligibility for transplantation, and the outcome is excellent. The shortage of organs from deceased donors has curtailed the adoption of extended criteria and led to the problems of long waiting times and dropouts. Several measures have been taken to tackle these issues, including prioritization of patients with HCC, use of pretransplant adjuvant treatment to prevent tumor progression, and living donor liver transplantation (LDLT). With a high incidence of HCC and a low organ donation rate, Asia has developed a distinctive pattern of indication and strategy in the application of liver transplantation. Over the last decade, the number of liver transplants in Asia has increased rapidly, by 10-fold, largely as a result of the development of LDLT. The proportion of patients who undergo liver transplantation for HCC is increasing and HCC comprises one third of the indication for liver transplantation in Asia. LDLT is the dominant strategy, accounting for 96% of the liver transplants for HCC. Many transplant programs accept patients beyond the Milan criteria, and the reported 3-year survival rate is about 60%. With the promotion of organ donation, better quantification of the benefit of LDLT for extended indications, and identification of predictors for survival, the practice of liver transplantation for HCC in Asia will continue to evolve.