What is Liver Transplantation?
Orthotopic liver transplantation (OLT) has become the definitive treatment for end stage liver disease (ESLD) and its complications as well as acute liver failure (ALF), primary liver cancer (hepatocellular carcinoma-HCC) and some metabolic diseases. What are the types of liver transplant?
There are two types of liver transplant:
1) Cadaveric: Here the organ is harvested from a brain dead individual who was an organ tissue donor.
2) Live Donor: Here a portion of the liver is taken from the healthy relative of the recipient who had undergone extensive workup for suitability prior to the surgery.
Who allocates organs for liver transplant?
In the United States, cadveric organs are allocated by the United Network for Organ Sharing (UNOS).
How does UNOS allocate organs?
UNOS allocates organs based on the MELD (Model for End stage Liver Disease) scoring system. MELD is a liver disease severity scoring system that uses three major biochemical parameters of a patient, i.e., Prothrombin Time/INR, Total Bilirubin and Creatinine in a logarithmic formula to predict survival.
The MELD score was implemented by UNOS on Feb. 27, 2002 in an effort to prioritize organ allocation, since it is highly predictive of three-month mortality from cirrhosis.
Transplant work up is usually initiated when the MELD score reaches around 15 or a major complication of cirrhosis is encountered. MELD score emphasis is on the acuity of the patient rather than the time spent on the waiting list.
For MELD score calculation please visit www.unos.org.
What are the indications for a liver transplant?
The indications for liver transplantation can be either acute (fulminant) liver failure from medication toxicity (most commonly acetominophen) or other toxic ingestions. Rarely acute viral hepatitis B cause fulminant hepatic failure necessitating a liver transplant.
Most cases of liver transplants are offered for end stage liver disease from any cause. In the United State, the most common indications for OLT are Cirrhosis from Hepatitis C, Alcohol, NASH, PBC and PSC. Less common causes are cirrhosis from Hepatitis B and metabolic diseases like hemochromatosis and Wilson’s disease.
Patients with Hepatocellular Carcinoma (HCC) are considered for liver transplantation if they meet certain criteria (Milan Criteria) which have been adopted by UNOS. This criteria state that there must be single tumor of less than 5cm or 3 tumors each measuring less than 3 cm.
Rare causes for a liver transplant are Alagille’s Syndrome, amyloidosis, sarcoidosis, polycystic liver disease (with or without simultaneous kidney transplantation), selected cases of neuroendocrine tumors, secondary biliary cirrhosis developing on the basis of previous common bile duct injuries.
What are the contraindications for a liver transplant?
Absolute Contraindications
- Active alcohol and or substance abuse
- Severe cardiopulmonary or other comorbid conditions that would preclude meaningful recovery after transplant
- Active extrahepatic malignancy
- Hepatic malignancy with macrovascular or diffuse tumor invasion and extrahepatic metastasis
- Active and uncontrolled infection outside of the hepatobiliary
system
- Technical and/or anatomical barriers: i.e. prior major abdominal surgery
- Psychosocial factors that would likely preclude recovery after liver transplantation
- Brain death
Relative Contraindications:
What are the components of a liver transplant workup?
A liver transplant workup is performed by a well trained team of physicians, nurses, social workers, dieticians and also includes consultation with various specialists based on each individual patient’s need, several imaging studies and a battery of laboratory tests. Prior to presentation to the Liver Transplant Selection Committee, all patients are expected to undergo the following procedures:
A) Consultations
Once the transplant hepatologist (Liver Transplant Medical Specialist) identifies a liver transplant candidate patient, work up is initiated in coordination with the liver transplant surgical team. All patients and their immediate family members are interviewed by the transplant social worker. In the absence of psychosocial contraindications, work up is pursued with other essential consultations.
All patients undergo cardiac work, usually with a stress echocardiogram. Also, pulmonary function tests are obtained. Patients with certain risk factors might also be required to be evaluated by a neurologist. Renal, pulmonary, psychiatric consultations are obtained on an as needed basis.
Patients with hepatocellular carcinoma HCC are usually required to be seen in consultation with an oncologist and an interventional radiology specialist, in preparation for pre OLT treatment, i.e., transarterial chemoembolization (TACE) or radiofrequency ablation (RFA).
B) Radiology
All patients undergo radiological evaluation by ultra sound (US) and CT scan of the abdomen. US exam also involves Doppler study of the portal vein, to check for its patency. CT scan with three phasic IV contrast is usually a reliable way of searching for HCC. MRI of the liver can be ordered for further evaluation, if suspicious lesions are identified on CT/US exams. Patients with HCC are also worked up with CT of lungs and brain as well as nuclear bone scans to look for potential metastatic disease. Chest X Ray, sinus X-Ray, and Panorex (X Ray of teeth) are also obtained. Occasionally MR angiography and cholangiography might be needed.
C) Laboratory Studies
- Blood type and antibody screen,
- A viral hepatitis profile, to include serum HCV-RNA titers, HCV genotype, HBV-DNA, hep B “e” antigen and antibody
- Autoimmune markers as well as iron and copper studies, immune protein electrophoresis
- Cancer markers, i.e. alpha fetoprotein (AFP), CEA, PSA (prostate specific antigen), CA 19-9
- Complete blood count (CBC), complete metabolic panel (CMP) to include magnesium and phosphate
- Coagulation studies, i.e., PT/INR, fibrinogen levels
- Cytomegalovirus (CMV) status, varicella titers, cryptococcal antibodies
D) Miscellaneous Procedures and Cancer Screening
1. Esophago-gastro-duodenoscopy (EGD): to screen for esophageal/gastric varices and to determine the extent of portal hypertensive gastropathy (PHG). This is important for bleeding risk stratification while the patient is on the waiting list. Usually the esophageal varices are endoscopically ligated with rubber bands.
 | | Figure 10. Esophago-gastro-duodenoscopy (EGD) |
2. Colonoscopy: All patients with cirrhosis older than age 40, or younger patients with higher risk (history of colitis or family history of early colon cancer), undergo screening colonoscopy with prostate digital exam being performed in men at the same time. Polyps are identified and endoscopically removed. Patients with precancerous polyps and with history of colitis or PSC, will require further screening colonoscopies every few years following liver transplant.  | | Figure 11. Colonoscopy |
3. Endocopic retrograde cholangio-pancreatography (ERCP): Patients with PSC or history of colitis will require this procedure to identify the biliary strictures and potential cholangiocarcinoma. Biliary brushings are routinely obtained to rule out malignancy, although the yield is generally low.
These procedures are performed by your transplant hepatologist who also coordinates the rest of the workup.
Liver biopsy is not required for the work up. In rare instances, if it is indicated (i.e., cryptogenic cirrhosis, tumor), it will be performed by your hepatologist or the intreventional radiologist. In cases of acute liver failure, transjugular approach (neck vein) can be used to obtain a liver biopsy.
Other tests prior to liver transplant are:
4. Mammogram and pap smear for female patients
5. Nuclear cardiac stress testing or coronary arteriogram, if recommended by the cardiology consultant.
E) Vaccinations:
- Hep A and B vaccination, if there is no evidence of prior immunity.
- Pneumovax (pneumonia vaccine, needs to be repeated every five years).
- Flu vaccination once a year.
- PPD skin test for TB screening is also applied.
After the full preparation period, patient is evaluated by the liver transplant surgeon, before being officially presented to the selection committee.
The selection committee consists of the above mentioned group of physicians and Liver transplant Anesthesiologists, as well as the social workers, pre and post liver transplant nurse practitioners (NP) and nurse coordinators (RN), financial coordinators and a secretary recording the minutes.
For more information, you can also visit the Comprehensive Transplant Center at: www.hopkinsmedicine.org/transplant
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