Frequently Asked Questions - How Organ Matching Works

The Transplant Waiting List

All patients accepted onto a transplant program's waiting list are registered with UNOS. UNOS maintains a centralized computer network linking all organ procurement organizations and transplant centers. Organ placement specialists operate the network 24 hours per day, seven days a week.

The Matching Process

When an organ becomes available, the local procurement organization coordinates the surgical recovery team, accesses the UNOS computer, enters information about the donor organs and runs the match program. This computer program generates a list of patients ranked according to objectives medical criteria such as blood type, tissue type, size of the organ and the patient's medical urgency. Other factors are time spent on the waiting list and distance between the donor and the transplant center. The specific criteria differ for each type of organ.

The computerized matching process can locate best possible matches between donor organs and the patients who need them, but the final decision rests with the patient's transplant team.

UNOS Organ Center

The Five Steps In Organ Matching

1. An organ is donated
   When an organ becomes available, the OPO managing the donor sends information to UNOS. The OPO procurement team reports medical and genetic information, including organ size and condition, blood type and tissue type.

2. UNOS generates a list of potential recipients
   The UNOS computer generates a list of potential transplant candidates who have medical and biologic profiles compatible with the donor's. The computer ranks candidates by this biologic information, as well as clinical characteristics and time spent on the waiting list.

3. The transplant center is notified of an available organ
   Organ placement specialists at the OPO or the UNOS Organ Center contact the centers whose patients appear on the local list.

4. The transplant team considers the organ for the patient
   When the team is offered an organ, it bases its acceptance or refusal of the organ upon established medical criteria, organ condition, candidate condition, staff and patient availability and organ transportation. The transplant team has only one hour to make its decision.

5. The organ is accepted or declined
   If the organ is not accepted, the OPO continues to offer it for patients at other centers until it is placed.

The Organ Offer

When an organ is offered, the transplant team must consider several factors to decide the best medical care for each individual patient. It is not unusual for a transplant team to say "no" to a particular organ. This is a normal part of the matching process. After being turned down for one patient, the organ is offered to the next patient on the list. These offers continue until the organ is placed.

How Policies Are Made

The organ distribution and matching process is based on policies developed by UNOS members. As the science of transplantation continues to advance, UNOS policies also evolve. The goal of UNOS policy-making is to create a system that gives every transplant candidate a fair chance at receiving the organ he or she needs. Organ transplantation is the only discipline in American medicine in which patients have a formal role in the policy-making process.

Facts About UNOS

• Organ sharing policies forbid favoritism based upon political influence, ethnicity, gender, religion or financial or social status. Sharing is based upon medical and scientific criteria.

• UNOS' Scientific Registry contains data on every solid organ transplant since October 1, 1987. This is the most comprehensive data analysis system for a single mode of therapy anywhere in the world.

• UNOS data are available on request. However, to protect the privacy of all transplant patients and ensure anonymity, each patient's name is replaced with a code number at registration.

• UNOS data enable scientists and physicians to exchange information vital for the progress of transplantation and help patients make informed decisions about their care.