The Evolution of Surgical Techniques for Pediatric Liver Transplantation

The shortage of organ donors is currently the most critical problem in clinical liver transplantation. In pediatric patients, the need for an appropriately sized liver donor implies the difficulty in obtaining suitable organs. Malatack and coworkers at the University Pittsburgh reported that 25% of children died prior to the procurement of a suitable liver &, and the risk is reported to be even higher for infants. In the ‘80s, it had been estimated that in the United States between 25% to 50% of infants waiting for liver transplantation died before transplantation due to limitation in the organ supply &.
The better understanding of liver functional anatomy allowed to theorize that a portion of the liver, with sufficient functional hepatocyte mass, with its vascular pedicle, bile duct, and venous drainage, could be transplanted in a patient, as well as a whole organ. In 1984, Bismuth and Hussein published the first clinical application of reduced-size liver transplantation &. This technique was adopted by several pediatric centers, with reported results comparable to those obtained with whole organ transplantation, allowing to almost eliminate patient mortality on the waiting list. Reduced liver transplantation redistributed organs from adults to children: it increased the number of pediatric donor organs, withdrawing organs from the larger adult recipient pool.
To overcome the limits of reduced liver transplantation, the use of a portion of the liver from a living donor was first attempted by Raia and colleagues in 1988 &, and successfully performed by Strong and colleagues in 1989 &. Living-related liver transplantation rapidly become an accepted and widely utilized procedure to alleviate donor shortage in pediatric patients. Until now, more than 1000 living-related liver transplants have been performed worldwide, obtaining good results. Compared to cadaveric whole organ or reduced liver transplantation, living-related transplantation allows the selection of an ideal donor and elective scheduling of cases. Its major drawback, however, is that it exposes a healthy person to the risks of a liver resection.
Emerging as a natural evolution of the techniques of reduced liver and living-related transplantation, was the idea of dividing the liver of a cadaveric donor, and transplanting the two functional subunits into two recipients: an adult and a child. In 1988 Pichlmayr and associates &, and one year later Bismuth and colleagues &, reported the first experiences with split liver transplantation.
The first series of 30 split liver transplantations was presented in 1990 at the American Surgical Association by the University of Chicago &. Patient survival rates were inferior to whole organ or reduced size cadaveric liver transplantation, with high incidence of technical and biliary complications. Despite the unsatisfactory results of the early experience, the method was accepted because it increased the number of liver grafts available for transplantation. Several series were published between 1995 and 1998 reporting improved patient and graft survival rates, and when these results were compared to those of conventional orthotopic liver transplantation performed during the same time period, they did not show a significant difference. Accumulating experience with ex vivo split liver transplantation also evidenced some drawbacks of this approach. The division of the liver allograft on the bench results in long ischemia time, with possible rewarming, causing graft injury, particularly if the two portions of the liver are transplanted successively or if a split graft is transported to another center.
In 1996 Rogiers and colleagues published a retrospective study, including seven in situ split liver procurements. The procedure was performed in heart-beating cadaveric donors, using the technique described for procurement of the left lateral lobe of a living-related donor &. In situ split liver procurement considerably reduced cold ischemia, eliminating ex situ benching. Moreover the anatomic integrity of the two grafts was assured with optimal hemostasis of the cut section respecting bile ducts vascularization.