Kidney exchange chains (a survey, including possibly the longest chain to date)

Here's a survey on non-simultaneous kidney exchange chains: Are Transplant Chains the Answer to Our Kidney Deficit? by Melissa Laracy

On long chains:
"Currently, the longest living kidney donor chain is the University of Alabama at Birmingham Kidney Chain. Started in December 2013, it has since grown to include 112 individuals, yielding a total of 56 kidney transplants as of December 2015."

See also "Celebrating the nation's longest kidney chain" at UAB