Surgeons at the The Johns Hopkins Hospital in Baltimore, Maryland, USA, have carried out the first simultaneous six-way kidney transplant operation involving six donors and six recipients that were paired using a “domino” system that relies on altruistic donation to facilitate better matching of recipients with volunteer donors.

The whole procedure, said to be the first six way transplant of its kind, was carried out last Saturday, 5th April, and took 10 hours, used six operating theatres and required nine surgical teams, involiving a total of 100 nurses, doctors and other medical and adminstration professionals.

According to a statement released by the hospital yesterday, all 12 patients are doing well.

The six-way “domino” procedure began when five of the recipients attended the hospital for evaluation, each with a willing donor (a relative or friend known to the recipient), but in each case, the donor’s tissue and blood type did not match the recipient’s.

It was only when a sixth volunteer donor was found, a so called “altruistic” donor who was prepared to donate a kidney to no particular recipient and whose blood and tissue type matched one of the recipients, that it then became possible to swap the pairs around so that each of the five recipients was better matched to receive a kidney from one of the donors, who was not necessarily a person they knew (ie not the donor they originally came forward with).

The kidney from the donor whose blood and tissue was least compatible with that of the five recipients was then available to donate to the first patient on the “waiting list” with a good match. Thus six well-matched donor-recipient pairs were created in a sort of “domino” effect with the last domino being the patient on the waiting list. (The “waiting list” was the United Network for Organ Sharing’s (UNOS) recipient list.)

In this kind of system, the more incompatible pairs that come forward, the greater the chance that better matched pairs can be created.

All six donor surgeries took place at the same time, after which the kidneys stayed in the same rooms, which were then sterilized before admitting the recipients and giving them their new kidneys.

Johns Hopkins said that each of the donors will now be monitored for the rest of his or her life to make sure the kidney they have left remains healthy. And the recipients will be monitored weekly for six weeks, then monthly, then gradually tapering off.

According to the hospital, the average life expectancy of a live donor kidney is around 18 to 20 years.

The transplant team at Johns Hopkins are the pioneers of the system where kidneys are exchanged among incompatible donor-recipient pairs. The procedure is called KPD, short for kidney paired donation.

The hospital were the first to carry out a KPD triple transplant in 2003, and two years later, in 2005, performed the first domino triple transplant and a year later, in 2006, the first domino five-way transplant.

Chief of the transplant division at Johns Hopkins Hospital, Dr Robert Montgomery, together with researchers from the hospital, presented a system for wider pairing of altruistic donors and incompatible recipients in a paper published in the Lancet last year. The intention was to substantially increase the number of organs available and to better serve the needs of donors and recipients.

Montgomery said that such a universal system obviates the inconsistencies of allocation systems where only a single patient benefits from an act of altruistic donation. It is often the case that the kidney from an altruistic donor goes either to someone at the top of the waiting list (regardless of predicted outcome or need), to a patient who is likely to live longer, or to someone in greatest need.

“With domino paired donation”, said Montgomery, “all three of these ethical tenets are satisfied.”

“The likelihood of a good outcome is increased by spreading the risk of recipient graft loss across more people. The neediest are served, since in many cases incompatible donor-recipient pools have a high proportion of patients who are hard to match,” he added.

“And fairness is served,” explained Montgomery, “because the last paired donor’s kidney in the chain is allocated to the next compatible patient on the deceased donor waiting list.”

Source: Johns Hopkins Medicine press release.

Written by: Catharine Paddock, PhD