What is kidney exchange?

People suffering from end-stage kidney disease are best treated with the transplantation of a donor kidney from a living donor. We will call these people looking to recieve a kidney recipients. Before the introduction of kidney exchange programmes, recipients had to find donors who were both willing and medically compatible. The choice to donate an organ is very personal, and so it can be tricky for a recipient to find a willing donor who may be medically compatible. A kidney exchange programme (KEP) helps to avoid this problem. Recipients pair up with a willing but medically incompatible donor. The kidney exchange programme will then assign donors to patients such that within each pair, the donor donates a kidney if and only if their paired recipient recieves a kidney. One form of kidney exchange is demonstrated below. Such an exchange is called a three-way exchange. In this exchange, recipient r1 is paired with donor d1, recipient r2 is paired with donor d2, and recipient r3 is paired with donor d3. The KEP has selected an exchange such that d1 donates to r2, d2 donates to r3, and d3 donates to r1.

A graphic depicting 6 people in three pairs of two. Each pair consists of a donor and recipient, and the pairs are indexed from 1 to 3. There is an arrow from d1 to r2, another arrow from d2 to r3, and an arrow from d3 to r1.

We see that in each pair, the donor is donating a kidney, and the recipient is recieving a kidney transplant. In this manner, we can increase the number kidney transplants that can be performed, saving the lives of people living with kidney disease.

On the next few pages, you will have a chance to find such exchanges for yourself.