Broken Chains and Reneging

A Review of 1748 Kidney Paired Donation Transplants

N. Cowan; H. A. Gritsch; N. Nassiri; J. Sinacore; J. Veale


American Journal of Transplantation. 2017;17(9):2451-2457. 

In This Article

Abstract and Introduction


Concerns regarding the potential for broken chains and "reneges" within kidney paired donation (KPD) and its effect on chain length have been raised previously. Although these concerns have been tested in simulation studies, real-world data have yet to be evaluated. The purpose of this study was to evaluate the actual rate and causes of broken chains within a large KPD program. All patients undergoing renal transplantation through the National Kidney Registry from 2008 through May 2016 were included for analysis. Broken chains and loops were identified. A total of 344 chains and 78 loops were completed during the study period, yielding a total of 1748 transplants. Twenty broken chains and one broken loop were identified. The mean chain length (number of transplants) within broken chains was 4.8 compared with 4.6 of completed chains (p = 0.78). The most common causes of a broken chain were donor medical issues incurred while acting as a bridge donor (n = 8), donors electing not to proceed (n = 6), and kidneys being declined by the recipient surgeon (n = 4). All recipients involved in a broken chain subsequently received a transplant. Based on the results, broken chains are infrequent, are rarely due to lack of donor motivation, and have no significant impact on chain length.


Kidney paired donation (KPD) affords the opportunity for patients with chronic kidney disease and an incompatible donor a means to obtain the benefits of living donor transplantation while avoiding costly desensitization regimens. Since its inception in 1986, many barriers to KPD have been overcome, including the development of national registries, shipping kidneys via commercial flights, and incorporation of nondirected donors (NDDs) into chains.[1–4] One of the first suggested barriers to overcome was the risk of a donor deciding against donation, initially referred to as "reneging," once their intended (but incompatible) recipient had received a kidney transplant.[5] To mitigate this risk, the collaborators in the first successful kidney exchange recommended that all donor operations be performed simultaneously.[5] Although this approach was possible with the simplest forms of KPD, increasingly complex strategies evolved utilizing nonsimultaneous donor operations. This furthered concerns regarding the potential consequences of a donor withdrawing their intent to donate after initiation of a chain sequence.[3]

We sought to determine the specific causes of broken chains in a modern KPD cohort and the prevalence of donors who elected not to donate (i.e., reneged) after their intended recipient had received a transplant. To study the impact of donors backing out on KPD outcomes, early reports relied on computer simulations requiring hypothetical data points because little real-world data were available.[6,7] These hypothetical simulation data were highly variable and had significant influence on simulated chain lengths. In an effort to clarify the actual rate of donors deciding against donation and to determine the real-world effect on number of transplants facilitated, our study reviewed outcomes from the United States's largest national KPD program. Furthermore, we aimed to evaluate the rates of broken chains as well as the effect of broken chains on the number of transplants facilitated.