Before undergoing a liver transplant, patients are put on a national waiting list. This list collects medical information for every person waiting for a new liver, allowing doctors to prioritize those with the most severe need. It is maintained by the United Network for Organ Sharing (UNOS).
How It Works
The national waiting list is a database that contains medical information (e.g., blood type, body size, and medical urgency) for anyone in need of a new organ in the United States and Puerto Rico. However, it is not a static list. Instead, whenever a new donor organ becomes available, its characteristics (e.g., size and blood type) are matched against the medical information of each candidate in the database. This generates a unique, one-time list.
Adult Liver Candidates
When a new liver becomes available, adult candidates (i.e., those over 12 years old) who are incompatible due to medical reasons (e.g., blood type or weight) are not included on the list. The remaining are prioritized based on medical urgency.
Patients with acute liver disease (less than 1 percent of all donor candidates) receive highest priority. For all other adult liver candidates, their priority score is calculated using the Model for End-Stage Liver Disease (MELD), which is a formula based on several lab tests:
- Bilirubin: A measurement of how effectively the liver excretes bile.
- INR: A measurement of the liver's ability to make blood clotting factors.
- Creatinine: A measurement of kidney function. Impaired kidneys are often associated with severe liver disease.
- Serum Sodium Level: A measurement of sodium in the blood.
Patients are rated on a scale of 6 (least severe) to 40 (most severe). The MELD score is then paired with additional factors, such as the patient’s distance from the donor hospital and chance of survival, to determine their priority.
Note: To ensure accuracy, MELD scores are continuously remeasured. The higher the score, the more frequently this is done:
- 6-10: Remeasured once a year.
- 11-18: Remeasured every 3 months.
- 19-24: Remeasured once a month.
- 25-40: Remeasured every week.
Read more about MELD and use the online MELD calculator on the Organ Procurement and Transplantation Network (OPTN) website.
Pediatric Liver Patients
For pediatric patients (12 years and younger), the Pediatric End-Stage Liver Disease (PELD) score is used to determine priority. Like MELD, it is based on lab tests such as bilirubin, INR, and creatinine. However, several other factors are also used:
- Albumin: Measurement of an essential protein made by the liver.
- Growth Failure: Measurement of the patient’s growth rate.
- Age: How old the patient is at the time of listing.
Read more about PELD and use the online PELD calculator on the Organ Procurement and Transplantation Network (OPTN) website.
An Alternative: Living Donor Liver Transplantation
Although the national waiting list helps allocate organs to those most in need, the demand for organs far outpaces the supply. For many, this means that wait times are an unavoidable part of the process.
For an alternative option, learn more about living donor liver transplantations.
If you or a loved one are in need of a liver transplant, we can help. Give us a call at (877) LIVER MD/ (877) 548-3763 or get in touch using our online request form.