Introduction: To examine the current techniques of split liver transplantation.

Technique: Split liver transplantation can be performed ex vivo or in situ using left-right or conventional (left lateral segment [LLS] and right trisegment [RTS]) splitting techniques. Each has its own set of advantages and disadvantages.

Ex vivo split: Ex vivo splitting requires decreased donor operating room time and results in acceptable patient and graft survival. However, it involves inadvertent graft re-warming, biliary complications, bleeding from the liver’s cut surface, and poorer outcomes in critically ill patients

In situ split: In situ splitting allows rapid identification of biliary and vascular structures, hemostasis during the parenchymal transection, and less warm and cold ischemia time. It also can facilitate graft sharing among transplant centers. Disadvantages include longer donor operating room time, the need for a stable donor, and the need for a skilled procurement team at the donor hospital.

Left-right split: Recipient selection for left-right split involves informed consent at the time of listing for transplant. The vessels should be tailored for the index patient, and the recipient should have minimal portal hypertension, if possible. Graft size and weight matching should be as follows: left recipient <60 kg and > 1% body weight; right recipient <80 kg and >1 % body weight.

Current issues with left-right split liver transplantation include whether it should be done ex vivo or in situ, the problem of venous outflow in the right lobe graft, small for size syndrome in the left lobe graft, and logistical considerations of the index patient.

Conventional split: In conventional in situ splitting, the decision to split is made in the operating room upon visualization of the liver. It uses standard operating room equipment, but requires an additional 1-2 hours prior to aortic cross-clamp. LLS grafts demonstrated long-term graft and patient survival equal to living-donor and whole-organ liver transplant outcomes with a slightly increased incidence of complications. RTS grafts demonstrated equal or better graft and patient survival compared to whole-organ grafts.

Conclusions: Whether performed ex vivo or in situ, split liver transplantation is a challenging operation that requires meticulous patient selection and meticulous surgical technique. Split liver grafts exhibit outcomes similar to cadaveric whole organs with only a slightly higher rate of complications. Split liver transplantation offers immediate expansion of the donor pool, and its routine use may decrease the dependency on living donation, thus overcoming the concerns of living donor safety.