Pushing the Limits of Live Donor Liver Transplantation: Is the Western World Ready for Dual Grafts?

I n this era of critical organ shortage, particularly in Asia, live donor liver transplantation (LDLT) has emerged as an effective option to reduce wait list mortality. However, at most centers, only 1 candidate is accepted out of every 3 or 4 applicants. Anatomic concerns are common reasons for exclusion. Some potential donors have right lobes that that are too small for the recipient, whereas others have vascular issues or a predicted liver remnant volume after resection that is too small for safe donation. To address these anatomic limitations, surgeons at the Asan Medical Center in Seoul developed and first described the use of dual grafts for adult-to-adult LDLT in 2001. Fifteen years later, this group now reports a 14-year experience with this innovative and technically challenging technique. Their use of dual grafts has grown over time. Even though the dual grafts liver transplants are a technical ‘‘tour de force,’’ the authors report outcomes in over 400 recipients nearly equivalent than those achieved with single grafts. Using dual grafts for adult LDLT, they have expanded their donor pool by 12%. Importantly, the risks to individual donors were not increased. Surgeons at the Asan Medical Center are to be congratulated for pushing the limits to find an innovative solution to the severe scarcity of donors suffered by Asian countries. Now that this procedure has become an integral part of their program, the question must be asked: Is the Western world ready for dual live donor liver transplants? To address this question, we have reflected on our own experiences. In 2016 at the University of Toronto, live liver donor transplants account for 17% of all adult cases (34/200 year to date) and 77% of pediatric cases (17/22 year to date). We have not yet offered ABO-incompatible LDLT, paired exchange, or dual live donor grafts, but we have promoted LDLT through education programs about the benefits of these procedures, by safely using older donors, by using small for size grafts, and by offering treatment of fatty livers with prescribed diets. Despite these measures, 50 to 100 patients listed for transplantation in our program die or are disqualified each year due to debility or cancer progression. This gap between donor liver supply and demand at our center, which also exists at most other programs in the Western world, provides a strong rationale to consider novel techniques such as dual graft transplants to alleviate wait list suffering and death. What is the potential increase in case volumes that might be achieved if we offer dual grafts? Since 2000, we have performed 570 adult live donor liver transplants. During this interval, there were also another 307 listed recipients who had 2 or more donors with unsuitable anatomy for a single liver graft who waited for a deceased donor liver transplant. Assuming that not all of the latter cases would be candidates for dual liver transplantation, our data suggest that offering dual grafts for LDLT in Toronto might increase the yearly adult LDLT activity by as much as 15% to 30%. Is it ethical to offer LDLT in the Western world where the option of deceased donation exists? From the recipient’s perspective, this question is easy to answer. The slight increase in rates of technical complications is clearly dwarfed by the overwhelming advantages of avoiding the risks of death or disqualification and regaining good health more quickly than waiting for a deceased donor liver. From the donor’s perspective, it could be argued that the total risk is doubled as 2 donors are put into risk. Nevertheless, the Seoul experience shows that the individual donor risk remains the same whether there are 1 or more donors. Moreover, one could argue that performing a less extensive hepatectomy in 2 donors may actually reduce the individual risks of serious, life-threatening complications in some cases. Therefore, we conclude that offering this procedure in the Western world is ethical provided donor safety is maintained as the foremost priority, good outcomes are achieved with dual grafts, and parties in this process provide fully informed consent. Who should perform dual graft LDLT? Institutions must be fully committed to live donation