The ethical limits in expanding living donor transplantation

The past decade has witnessed the emergence of novel methods to increase the number of living donors. Although such programs are not likely to yield high volumes of organs, some transplant centers have gone to great lengths to establish one or more of them. I discuss some of the ethical and policy issues raised by five such programs: (1) living-paired and cascade exchanges; (2) unbalanced living-paired exchanges; (3) list-paired exchanges; (4) nondirected donors; and (5) nondirected donors catalyzing cascade exchanges. I argue that living-paired and cascade exchanges are ethically sound, but will lead to only a few additional transplants. Unbalanced exchanges and list-paired exchanges raise ethical issues that should limit their permissibility. Nondirected donations can be ethically sound with adherence to strict eligibility criteria and fair allocation procedures. Nondirected donors catalyzing cascade exchanges can be ethically sound provided that individuals with blood types O and B are not made worse off.