Split liver transplantation — outlook to the future

Abstract

When I speak about complications related to liver transplantation with a patient, I never mention the main complication of liver transplantation — being not transplanted. According to UNOS a significant number of patients on the waiting list will have to wait longer than two years, which is unacceptable. It means, depending on the indication, that many of these patients will have to die. And due to expansion of indication and shortage of organs, mortality on the waiting list continuously rises. In Europe the number of liver transplantations has plateaued for about four years now. That means we cannot expect expansion of the numbers of donors in the next few years. So the only answer to this dilemma — beyond improving the liver transplantations in our patients we perform today — is shown in Fig. 1. It is a slide in a lecture one might give in 3 to 4 years routinely showing that a donor has to give 2 lungs, 1 heart, 2 kidneys and 2 livers. For many years, anatomy has already been talking about two livers. One speaks of removing the right liver or the left liver. Yet this is not anchored enough in the mind of the liver transplant surgeon. Today we must think of the liver as source for two liver grafts as a standard concept. The donor has to be considered as one with two livers and both have to be allocated like other paired organs. As reported by Azoulay et al. (1996), de Ville de Goyet et al. (1999) and Busuttil et al. (1999), the liver is a splitable organ in about 30% of the cases. So the first step is to define the donor that is ideal for splitting. Basic characteristics for the ideal donor would be an age of less than 60 years and more than 70 kg of body weight. There should be no history of cardiac risk and the donor should be in a dynamically stable condition with no or minimal vasopressors. The liver should be free of steatosis and the presumed liver weight should be above 1.8 kg. A donor like this should be reported to the allocating organization as a donor with two livers. To minimize organizational problems due to the fact that one has to deal with two recipient centers, surgical techniques to split the liver need to be standardized. The right liver should be the one without the vena cava, with the right hepatic vein only (no middle vein) and with part of the right pedicle. There is a lot of experience with this approach especially from living-related donation as reported by Professor Tanaka.