Split liver transplantation: an overview

Liver transplantation (OLT) has become the only treatment modality for patients with end-stage liver diseases. Establishment of standard liver transplantation technique, development of better immunosuppressive medications and accumulated experience using them safely, and improvement of intensive care and anesthesia played major role to have current 88%-90% 1-year survival after liver transplantation. As liver transplantations became more successful with the growing experience and development in the field, the increased demand for liver allografts could not match the available supply of donor organs. As a result of this imbalance, each year nearly 3000 patients die in the United States awaiting liver transplantation on the national waiting list. Split liver transplantation (SLT) has been perceived as an important strategy to increase the supply of liver grafts by creating 2 transplants from 1 allograft. The bipartition of a whole liver also carries utmost importance by increasing the available grafts for the pediatric patients, where size-matched whole liver allografts are scarce, leading increased incidence of waiting list mortality in this group. In the common approach of the split liver procedure, liver is divided into a left lateral segment graft (LLS) to be transplanted to a child and a right extended liver lobe graft for an adult recipient. In a technically more challenging variant of this procedure, the principle is to split the liver into 2 hemigrafts and use the left side for a small adult or a teenager and the right for a medium-sized adult patient. Donor selection for splitting, technical expertise in both OLT and hepatobiliary surgery, logistics to decrease total ischemia time, and manpower of the transplantation team are important factors for successful outcomes after SLT. The liver can be split on the back table (ex situ) or in the donor hospital before the donor cross-clamp using in situ splitting technique, which was developed directly from living donor liver transplantation. The most important advantage of in situ splitting is to decrease the total ischemia time and increased the possibility of inter-center sharing. The in situ technique of splitting has other advantages, including evaluation of the viability of segment IV in case of LLS splitting and better control of bleeding from cut surface upon reperfusion on the recipient. Recipient selection for split liver grafts is also crucial for success after SLT. In this review, we aim to summarize the advances that have occurred in SLT. We also discuss anatomic and technical aspects, including both approaches to SLT, which is now considered by many centers to be a routine operation.