In the United States, the National Kidney Registry organizes the majority of U.S. KPD transplants,[3][4][5] including the largest swaps.
KPD is also being used to find better donor–recipient matches for compatible pairs who want a lower lifetime mortality[1][13] and longer lasting transplant.
[8] For nearly a decade, only Park and his team in South Korea utilized this novel approach to facilitate transplants for incompatible donor–recipient pairs.
[26] The Hopkins program, which was based out of the Johns Hopkins Hospital, led the industry in early innovations including the critical "domino chain" breakthrough which allowed Good Samaritan donors to start chains,[27] dramatically increasing the number of pairs that could be matched in a swap compared to the loop approach that was used previously.
A bridge Donor is someone whose paired recipient has received a kidney but does not donate for some period of time (generally 1 week to 3 months).
Initially, NKR provided donors with the option of traveling to the matched recipient's hospital or donating locally and having their kidney shipped.
In 2009, several more key innovations were yielding results at a single center KPD program, the Methodist Transplant Institute, in San Antonio led by Dr. Adam Bingaman.
This approach accelerates the matching process, reduces swap failure rates and provides the ability to speculatively cross match potential donors for highly sensitized patients, leading to shorter wait times and more transplants for highly sensitized patients.
The only U.S. multi-center KPD program that successfully implemented cryo-preservation was the National Kidney Registry[32] but only after establishing a central lab and investing three years in software development.
The preselect concept eliminated the need to use supercomputers for match runs because the number of valid one-ways was dramatically reduced.
In 2012, the National Kidney registry organized the largest swap in history which included 60 surgeries, completed over five months.
In 2014, the National Kidney Registry set a new record by organizing a swap that included 70 surgeries completing over two months.
[36] Prior to KPD, there was no reason to ship living donor kidneys and therefore, there was no understanding of the impact of CIT on outcomes.
This concern proved to be unfounded as more living donor kidneys were shipped and the research demonstrated that CIT had no negative impact on KPD outcomes.
[39] Researchers are working to better understand why NKR KPD transplants have superior outcomes and believe it may be driven by better HLA and donor age matching and/or better avoidance of recipient antibodies.
As paired exchange grew and the process became faster and more reliable, patients with compatible donors that wanted a better match, began enrolling in KPD.
A favorable blood type compatible pair (i.e. O donor with non-O recipient) will facilitate at least one and as many as six additional transplants.
As adoption of Advanced Donation increased, due to the timing advantages that made donation surgery more convenient for the donor, the size and complexity of KPD swaps were reduced, with the logical extension of this trend being the eventual elimination of traditional chain and loop swaps, replaced by 1-deep chains.