Adult liver transplantation was initiated at Stanford Hospital and Clinics in 1991 as part of the Multi-Organ Transplant Center. In 1995, the adult and pediatric liver transplant team, formerly at California Pacific Medical Center, was recruited to Stanford. The team has performed more than 1200 liver transplants and has had a good one-year survival rates.
Patients who may benefit from liver transplantation should be referred as early as possible, because the waiting time for a liver transplant may be two to three years in the Bay Area. Listed below are some of the selection factors and contraindications for liver transplantation:
Adult Patient Selection and Process of Listing with UNOS
Before final selection and listing for liver transplantation, the prospective candidate undergoes a pretransplant evaluation, which can usually be completed on an outpatient basis over 2 to 3 days. The transplant coordinator and transplant hepatologist are the key individuals who facilitate this evaluation and educate the patient and family members. A comprehensive evaluation is required to determine if absolute or relative contraindications are present and to define the current status of systemic diseases. All outside medical records and liver biopsy materials are reviewed. Routine evaluation includes hematologic and blood bank studies, complete chemistry profile, viral serology (HBV, HCV, HIV, CMV), chest X-ray, and computed tomography of the abdomen or abdominal ultrasound with examination of blood flow in hepatic vessels. Patients also have routine electrocardiogram and undergo pulmonary function testing if there is a history of lung disease. PPD testing for tuberculosis is routinely performed. Renal function is assessed by creatinine clearance. Transplant candidates over the age of 60, candidates over the age of 50 with risk factors for coronary artery disease, and patients with a history of cardiac disease undergo cardiology consultation with appropriate cardiac studies, often including stress thallium and/or cardiac catheterization. Doppler of carotid of peripheral vessels may also be appropriate. Consultations with a social worker, financial counselor, and psychiatrist are routine in most centers. Cancer screening with pap smear, mammogram, fecal occult blood testing, and flexible sigmoidoscopy, depending upon age and gender, is completed.
Once the pretransplant evaluation is complete, the patient is presented to the Liver Transplant Selection Committee made up of the entire transplant team, including consultants, for categorization and prioritization. Patients are generally assigned to one of four categories: 1) suitable and ready, with listing for a donor organ; 2) suitable but too well, with placement on inactive status and continued follow-up with the referring physician; 3) potentially reversible current contraindication, with treatment and recategorization at a later date; and 4) absolute contraindication, with denial of transplantation.
Patients who are approved for liver transplantation by the selection committee are then listed for a donor organ with UNOS, and final approval by the insurance carrier or third party payer is sought. UNOS had has a federal contract to operate the national Organ Procurement and Transplantation Network since 1986. Livers are donated in the spirit of altruism and are a limited national resource; thus, it is only right that donor livers be allocated in a fair manner. Federally designated local Organ Procurement Organizations (OPO) facilitate equitable distribution of donor livers and act as a bridge between a donor hospital (a hospital with a patient who is an organ donor) and the local transplant center(s). It is the policy of UNOS that all potential recipients of organ transplants must be listed on the national UNOS computer waiting list, with the priority for a donor organ determined by factors discussed below. Patients with chronic liver disease must meet "minimal listing criteria" (Child-Pugh class B, or score >= 7, or episode of either variceal bleed or spontaneous bacterial peritonitis) to be listed with UNOS (see Tables 1 and 2).
How does the UNOS list work? UNOS establishes policies regarding organ distribution and allocation based on broad consensus and periodically amends these policies. The historical allocation scheme has been that the sickest patient who has waited the longest receives the next available liver. Donor organs that become available in the local area (California Transplant Donor Network, or CTDN, is the OPO serving the Bay Area) are offered to patients on the waiting list of the local transplant centers, with the exception of patients listed as status 1 who may receive organs from anywhere in the entire UNOS region. When there is not a good match for any patient at a local center, a donor liver is sent out of the local area; conversely, local transplant centers also sometimes receive livers from distant hospitals, particularly for the most ill patients. In general, a donor is matched to a potential recipient on the basis of several factors: ABO blood type, body size, time waiting, and degree of medical urgency. UNOS utilizes a computerized point system to distribute organs in a fair manner. Recipients are chosen primarily on the basis of medical urgency and time waiting within each ABO blood group. The average waiting time for a patient to receive a liver once they are listed with UNOS has increased and may be as much as 12 to 48 months depending on disease severity. The waiting time varies according to the blood type, e.g. patients with O blood type wait longer on average, and patients with B blood type wait for a shorter period of time. Unfortunately, many more patients today who are referred and selected at an appropriate time in the natural history of their disease will deteriorate during the long wait for a donor organ. Local referral physicians and transplant center personnel together support patients approved and listed for transplantation during this crucial waiting period. The medical urgency, or disease severity, policies have undergone revision on a regular basis and are summarized as of January 2003.
| Table 1. Child-Pugh Classification | 1 point | 2 points | 3 points |
|
Bilirubin (mg/dL)
|
< 2 < 4 |
2 - 3 4 -10 |
> 3 >10 |
| Albumin (g/dL) | > 3.5 | 2.8 - 3.5 | < 2.8 |
|
PT: sec prolonged
|
1 - 3 < 1.7 |
4 - 6 1.8 - 2.3 |
> 6 > 2.3 |
| Ascites | none | slight | moderate |
| Encephalopathy | none | 1 - 2 | 3 - 4 |
|
PBC = primary biliary cirrhosis; PSC = primary sclerosing cholangitis; PT = prothrombin time; INR = international normalized ratio Child-Pugh class and score: A = 5-6 points; B = 7-9 points; C = 10-15 points |
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| Table 2. Non-disease-specific Minimal Listing Criteria. |
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| Table 3. Criteria for liver transplantation in fulminant hepatic failure. |
|
King’s College Criteria
|
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Clichy Criteria Hepatic encephalopathy, and:
|
The United Network for Organ Sharing (UNOS) implemented a new organ allocation
system in the spring of 2002. The recommendations regarding organ allocation
using the Model for End-stage Liver Disease (MELD) and corresponding Pediatric
End-stage Liver Disease (PELD) scoring systems that are summarized below were
developed by the UNOS Liver and Intestinal Organ Transplantation Committee,
on which Dr. Keeffe served as a member. The Board of Directors of UNOS endorsed
the MELD/PELD scoring system at their June 2001 meeting and give final approved
at their November 2001 meeting of the Board of Directors.
It is now important for routine laboratory studies on all of our patients on the UNOS waiting list to include not only serum total bilirubin and creatinine as before, but also INR. For patients with high MELD scores and likely to be transplanted in the near future, the individual MELD score for patients must be reviewed weekly and can be updated as frequently as daily to increase their priority status.
For those seeking further information, a comprehensive review of the MELD and PELD scoring system was recently published by Dr. Wiesner and colleagues (Liver Transplantation 2001;7:567).
| Hepatocellular Carcinoma: Revised UNOS Listing Criteria for Extra Priority |
Policy 3.6.4.4 Patients with T1 tumor (1
nodule <= 1.9 cm) Patients with T2 tumor (1
nodule 2.0 – 5.0 cm; 2 or 3 nodules, all < 3.0 cm) Patients with AFP > 500
ng./mL on any one occasion without tumor on imaging
studies may be listed as stage I (MELD = 20)
Additional MELD points =10% mortality (MELD score 3-4) may be added every 3 months with continued documentation of tumor by CT or MRI (chest CT and bone scan not required) Patients with downsized tumors (original/presenting tumor was > T2 and then treated with ablative therapy) must be referred to RRB for prospective approval before listing with extra priority MELD points A patient not meeting above criteria can still be transplant by individual centers, but will not receive the bonus MELD points. A patient with HCC not meeting above criteria can be referred prospectively to the RRB for consideration of bonus MELD points. Post-transplant pathology reports must be send to UNOS Policy Compliance Department; pathology reports not showing HCC will be sent to the local RRB. |