Navigating challenges in recipient selection for end-chain kidneys.

As a result of the increasing number of transplants being facilitated by kidney paired donation and newer initiatives such as voucher donation, end-chain (EC) kidneys now constitute a considerable proportion of kidney paired donation transplants in the United States. Data on EC kidneys are limited. They may be lower in quality compared with non-EC living donor kidneys. However, they can provide unique opportunities for recipient candidates without living donors. There are no data or algorithms available to guide recipient selection for EC kidneys accepted by a transplant center. Considering the ethical principles of utility, justice, and respect for persons that underlie organ allocation, we discuss 3 potential approaches for recipient selection: (1) adherence to the kidney allocation system, (2) utility maximization; and (3) priority to high-risk candidates, along with examples from our own center's experience. Similar considerations are also relevant to selection of recipients for nondirected donor organs and to out-of-sequence allocation for deceased organ donors. Because EC kidneys represent an increasing proportion of kidney paired donation-facilitated living kidney donor transplantation in the United States and will likely get more medically and surgically complex over time, ongoing research on their utilization and outcomes is needed.