Why Living Liver Donation?
There is a tremendous need for liver transplants that isn’t being met through cadaveric donation. UNOS figures show more than 16,000 people await liver transplants, yet only about 5,000 transplants actually occur. There is an enormous gap.
Enter living donation. The special characteristics of the human liver make living donation unique. While each of us has only one liver, it is a large, segmented organ that regenerates, allowing a surgeon to remove a portion yet have both the recipient and donor with complete livers within a matter of a few months.
Living donation has important advantages over cadaveric donation:
- The waiting time for a transplant recipient can be significantly reduced.
- The procedure can be scheduled at a time convenient for both the donor and recipient.
- The quality of the donated organ tends to be superior to cadaveric organs.
- The time between procurement of the organ and transplantation to the recipient is minimized.
While all of these things have proven valuable for living kidney donation, research has not yet clearly shown the advantages of living liver donation over cadaveric donation. Moreover, the surgery is more complex, bringing greater risk to the donor and recipient. However, graft and patient survival rates are very good. Graft (donated organ) survival results for living donors alone are not available, but results combined with cadaveric donations are:
|Time after Donation||
Percent of Grafts Surviving
The sample size of living liver donors is fairly small, and the characteristics can be a consequence of factors other than demographics. With that caution, here is a summary of living donor features from 1998:
- Most (64.1%) were between the ages of 18 and 34.
- Two-thirds were white, 20.5% black, and 12.8% Hispanic.
- Half were male, and half were female.
- 58.6% were blood type O, 32.9% were type A, 8.6% type B, and none were type AB.
- The majority of donors (84.2%) were parents of the recipient, 7.9% children, 2.6% identical twins, no siblings, 5.3% other relatives, and no unrelated donors. (Note that UNOS did not have data on the relationship for nearly half the donors.)
These results, combined with evidence that the majority of liver transplant recipients are children under age 18, suggest living liver transplants are mostly from parent to child.
Living liver donation grew out of experience with cadaveric donations, specifically the use of “reduced” or “split-liver” donations using just a portion of the liver. Physicians learned only a portion of a donated liver was needed. The first living transplant was from an adult to a child performed in Australia in 1989. The procedure is now common at major pediatric centers.
More recently, techniques have been developed for adult-to-adult donation, which requires a larger portion of the donor liver. The first such donation occurred in 1995.
As with kidney donation, there is increasing interest in “nondirected” or living unrelated donation from strangers. The first such donation in the US occurred in 1999.