Collaborative Research: Kidney Exchange

2004年9月，新英格兰肾移植监督委员会批准建立一个肾脏交换信息交换所。弗朗西斯·德尔莫尼科，苏珊·赛伊德曼和这一建议的作者，导致了2005年夏天新英格兰肾脏交换计划（NEPKE）的建立。作者与移植社区和实际实施的互动揭示了肾脏交换的几个有趣的方面。本文主要从以下几个方面进行分析：3-Way肾脏交换的重要性：为了避免捐赠者在他们所爱的人接受移植后选择退出系统，所有四项手术都应该同时进行2-way肾脏交换。同样，在三路肾交换中，所有六项手术应同时进行，以此类推。由于这种逻辑上的限制，双向交换一直备受关注。在赛德曼等人（2005）的模拟中，模拟结果表明，三方交换的可用性显著增加了通过交换接受移植的患者数量，而当更大规模的交换可用时，边际效益要小得多。我们提出了一个重要的三向肾交换理论。中心激励：肾脏交换的预期收益随着患者供体数量的增加而增加。美国的许多移植中心正在合作进行肾脏交换。例如，neke是由新英格兰所有14个移植中心参与建立的。该系统的一个重要障碍是避免单个中心只向集中池提供更难匹配的配对，并保持容易匹配的患者-供体配对在中心内进行匹配。研究者发展了一种中心激励理论和设计机制，以鼓励中心充分参与肾脏交换。与好撒玛利亚人交换肾脏：虽然很少，但偶尔会有好撒玛利亚人捐赠肾脏给肾病患者，而不期望得到肾脏的回报。将好心人的捐赠与肾脏交换结合起来是很重要的。这样，虽然每个好撒玛利亚人只捐出一个肾脏，但他/她可以促进其他在他/她不在时无法进行的移植。研究人员分析了好撒玛利亚人的模型，并模拟了将好撒玛利亚人捐赠与肾脏交换相结合的潜在收益。动态肾脏交换：现有的肾脏交换理论，就像许多关于各种匹配市场的理论一样，是静态的。然而，实际问题是动态的。研究者发展了肾脏交换的动态理论。建议活动的智力价值：建议的研究将有助于配对市场和实际机制-市场设计的文献。更广泛的影响：我们预计一些研究结果将影响美国包括新英格兰在内的各个地区肾脏交换的组织。

In September, 2004, the Renal Transplant Oversight Committee of New England approved the establishment of a clearinghouse for kidney exchange, proposed by Drs. Francis Delmonico, Susan Saidman and the authors of thisproposal which lead to the establishment of New England Program for Kidney Exchange (NEPKE) in Summer, 2005. The interaction of the authors with the transplantation community and practical implementation revealed several interesting aspects of kidney exchange. This proposal is on the analysis of the following aspects:1. The Importance of 3-Way Kidney Exchange: In order to avoid donors opting out from the system once their loved ones receive a transplant, all four operations should be conducted simultaneously in a 2-way kidney exchange. Similarly in a 3-way kidney exchange all six operations should be conducted simultaneously, and so on. Due to this logistical constraint, much attention has been on 2-way exchanges. In Saidman et al (2005), simulations reveal that availability of 3-way exchanges significantly increases the number of patients who receive transplants through exchange whereas the marginal benefit is much smaller when larger exchanges become available. We develop a theory of the importance 3-way kidney exchange.2. Center Incentives: Expected gains from kidney exchange gets larger as patient-donor pools increase in size. Many transplant centers in the U.S. are in the process of collaborating on kidney exchange. For example NEPKE was established by participation of all fourteen transplant centers in New England. One important hurdle for the system is avoiding individual centers to offer only harder to match pairs to the centralized pool and keep easy to match patient-donor pairs to be matched within the center. The investigators develop a theory of center incentives and design mechanisms to encourage full center participation in kidney exchange.3. Kidney Exchange with Good Samaritan Donors: Although rare, occasionally a good Samaritan donates a kidney to a kidney patient without expecting a kidney in return. It is important to integrate donations from good Samaritans with kidney exchange. In this way, although each good Samaritan donates only one kidney, he/she can facilitate other transplants which would not be possible in his/her absence. The investigators analyze the model with good Samaritans and simulate the potential gains from integrating good Samaritan donations with kidney exchange.4. Dynamic Kidney Exchange: The existing theory on kidney exchange, like much of the theory on various matching markets, is static. The practical problem, however, is dynamic. The investeigators develop a dynamic theory on kidney exchange.Intellectual Merit of The Proposed Activity: The proposed study will contribute to the literature on matching markets and practical mechanism - market design.Broader Impact: We anticipate some of the findings to influence the organization of kidney exchange in various parts of U.S. including in New England.