Split liver transplantation

Long-term results after adult ex situ split liver transplantation since its introduction in 1987

BACKGROUND

Split liver transplantation is still discussed controversially. Utilization of split liver grafts has been declining since a change of allocation rules for the second graft abolished incentives for German centres to perform ex situ splits. We therefore analysed our long-term experiences with the first ex situ split liver transplant series worldwide.

METHODS

A total of 131 consecutive adult ex situ split liver transplants (01.12.1987-31.12.2010) were analysed retrospectively.

RESULTS

Thirty-day mortality rates and 1- and 3-year patient survival rates were 13, 76.3, and 66.4 %, respectively. One- and three-year graft survival rates were 63.4 and 54.2 %, respectively. The observed 10-year survival rate was 40.6 %. Continuous improvement of survival from era 1 to 3 was observed (each era: 8 years), indicating a learning curve over 24 years of experience. Patient and graft survival were not influenced by different combinations of transplanted segments or types of biliary reconstruction (p > 0.05; Cox regression). Patients transplanted for primary sclerosing cholangitis had better survival (p = 0.021; log-rank), whereas all other indications including acute liver failure (13.6 %), acute and chronic graft failure (9.1 %) had no significant influence on survival (p > 0.05; log-rank). Biliary complications (27.4 %) had no significant influence on patient or graft survival (p > 0.05; log-rank). Hepatic artery thrombosis (13.2 %) had a significant influence on graft survival but not on patient survival (p = 0.002, >0.05, respectively; log-rank).

CONCLUSIONS

Split liver transplantation can be used safely and appears to be an underutilized resource that may benefit from liberal allocation of the second graft.

Why does living donor liver transplantation flourish in Asia?

The success of liver transplantation worldwide has brought increased demand for the liver graft. Western and Asian countries have coped differently with the problems of the shortages in organ donation. In the West, efforts have focused on promoting deceased donor organ donation, whereas in Asia the focus has been on living donor liver transplantation (LDLT), as this procedure is more acceptable in most Asian cultures. LDLT, which was initially devised for paediatric liver transplant patients, has evolved from using a left lobe graft to a right lobe graft for an adult recipient. To widen the donor pool, dual grafts for a single recipient have been used in LDLT, and donors with hepatitis B core antibody positivity have been accepted, as well as ABO incompatible donors and recipients. The great advances in the field of LDLT have been dictated by the needs and the norms of Asian society. In this Perspectives article, we outline the reasons why LDLT flourishes in Asia.

Life in the Fas lane: differential outcomes of Fas signaling

Fas, also known as CD95 or APO-1, is a member of the tumor necrosis factor/nerve growth factor superfamily. Although best characterized in terms of its apoptotic function, recent studies have identified several other cellular responses emanating from Fas. These responses include migration, invasion, inflammation, and proliferation. In this review, we focus on the diverse cellular outcomes of Fas signaling and the molecular switches identified to date that regulate its pro- and anti-apoptotic functions. Such switches occur at different levels of signal transduction, ranging from the receptor through to cross-talk with other signaling pathways. Factors identified to date including other extracellular signals, proteins recruited to the death-inducing signaling complex, and the availability of different intracellular components of signal transduction pathways. The success of therapeutically targeting Fas will require a better understanding of these pathways, as well as the regulatory mechanisms that determine cellular outcome following receptor activation.

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.

Ethics and rationale of living-donor liver transplantation in Asia

Living-donor liver transplantation took root in Asia as a natural result of circumstances, because the supply of organs from the cadaveric pool remained scarce over the years. In contrast to Western countries, the majority of organs for liver transplantation in Asia come from live donations. As the expertise of the transplant teams grows, patient outcomes improve, and public awareness increases, the option of live donation of the liver is increasingly chosen. Although no live liver donor death has yet been reported from Asia, the risk is not eliminated and remains a major consideration in the potential donor's decision to donate. The low morbidity and mortality rate could be attributed to the extensive experience of surgeons in liver surgery, because surgical liver disease is highly prevalent in Asia. Although the donor risk is estimated to be low, live organ donation should be absolutely voluntary, with consent given on the basis of unbiased information and chosen only when the option for obtaining a cadaveric graft is practically nil. It is only under these conditions that living-donor liver transplantation should be perpetuated. Although the disease-donation-transplantation process involves a complex interplay of psychosocial and family dynamics, the potential candidate's perception will necessarily depend on the surgeon's explanation. The ethical soundness of the practice of living-donor liver transplantation rests primarily on the ones who deliver the service.