Objective: This study reviews the indications, technical aspects, and experience with ex vivo and in situ split liver transplantation.
Background: The shortage of cadaveric donor livers is the most significant factor inhibiting further application of liver transplantation for patients with end-stage liver disease. Pediatric recipients, although they represent only 15% to 20% of the liver transplant registrants, suffer the greatest from the scarcity of size-matched cadaveric organs. Split liver transplantation provides an ideal means to expand the donor pool for both children and adults.
Methods: This review describes the evolution of split liver transplantation from reduced liver transplantation and living-related liver transplantation. The two types of split liver transplantation, ex vivo and in situ, are compared and contrasted, including the technique, selection of patients for each procedure, and the most current results.
Results: Ex vivo splitting of the liver is performed on the bench after removal from the cadaver. It is usually divided into two grafts: segments 2 and 3 for children, and segments 4 to 8 for adults. Since 1990, 349 ex vivo grafts have been reported. Until recently, graft and patient survival rates have been lower and postoperative complication rates higher in ex vivo split grafts than in whole organ cadaveric transplantation. Further, the use of ex vivo split grafts has been relegated to the elective adult patient because of the high incidence of graft dysfunction (right graft) when placed in an emergent patient. Reasons for the poor function of ex vivo splits except in elective patients have focused on graft damage due to prolonged cold ischemia times and rewarming during the long benching procedure. In situ liver splitting is accomplished in a manner identical to the living donor procurement. This technique for liver splitting results in the same graft types as in the ex vivo technique. However, graft and patient survival rates reported for in situ split livers have exceeded 85% and 90%, respectively, with a lower incidence of postoperative complications, including biliary and reoperation for bleeding. These improved results have also been observed in the urgent patient.
Conclusion: Splitting of the cadaveric liver expands the donor pool of organs and may eliminate the need for living-related donation for children. Recent experience with the ex vivo technique, if applied to elective patients, results in patient and graft survival rates comparable to whole-organ transplantation, although postoperative complication rates are higher. In situ splitting provides two grafts of optimal quality that can be applied to the entire spectrum of transplant recipients: it is the method of choice for expanding the cadaver liver donor pool.