When an organ is donated from a person who has died, it is made available to an eligible patient on the waiting list. Before the transplant can take place, however, several things happen.

1. The local Organ Procurement Organization (OPO) gathers information about the organ - size, condition, blood and tissue type - and sends this to the United Network for Organ Sharing (UNOS). UNOS is a national organization that operates the patient waiting list, assuring equal and fair access for all patients to organs for transplantation.

2. A patient on the UNOS list who is most qualified for the organ - due to waiting time, blood and tissue match, and other factors - is selected and his or her center is notified.

3. Although a patient meets all the criteria and appears to be a good match for the organ, the organ still has to be accepted by the transplant center. The transplant team has a very short time to consider several factors before accepting that organ for the particular patient. If, in the physician's judgment, the organ offered presents undue risks to the patient, it may be refused. There are a number of reasons for refusing an organ, such as:

• Patient condition - The patient may currently be too ill to undergo surgery. Or, the patient may be out of town or otherwise unavailable for surgery at that time.

• Donor condition - The donor might have had high blood pressure, diabetes or some other illness that might have harmed the donated organ.

• Organ condition - If an organ has been outside the donor's body for too long it might not work as well and may not help the patient. Or, the organ might have been damaged during recovery from the donor or during transit to the transplant center. Sometimes, final examination of the organ shows previously unseen risks, such as too much fatty tissue or badly formed blood vessels.

• Donor/recipient compatibility - Critical "matching" tests, done just prior to surgery, sometimes reveal unknown incompatibilities that would result in failure of the transplant.

• Transplant center factors - Geography may be a factor, as it may not be possible to get the organ to the center within a desirable amount of time.

There are some differences among transplant centers overall in terms of how often organs are accepted or refused. But recent studies have found that how often a center accepts or refuses transplant organs does not seem to affect such important factors as how long patients wait for transplant or how well those patients do either before or after transplant.*

* From the United Network for Organ Sharing (UNOS') Summary of Key Findings 1113197. The UNOS 1997 Report on Center-Specific Organ Acceptance Rates.