What Is A Liver Transplant?

Individuals with severe liver failure, and other serious liver diseases, may have the opportunity to undergo a liver transplant to cure their disease or prolong their life.

Liver transplant surgery involves the removal of a person's diseased and dysfunctional liver. Following the removal, a portion of or an entire healthy liver from a donor is used to replace it. The donor can be alive or deceased.

Liver functioning is critical to your health as the liver is involved in numerous crucial body processes.

When can a liver transplant be performed?

Liver transplants are usually a last resort treatment for individuals at risk of severe complications due to liver failure. Liver transplant surgery can potentially save people’s lives. However, many more people are in need of liver transplants than there are deceased donors of livers.

Because suitable donors of complete livers are rare and may take too much time to find, an alternative is to have a living-donor liver transplant. The liver can fully regenerate in the donor after having a portion of it removed. 

Three factors help doctors to consider if a patient may be a good candidate for a liver transplant:

1. The patient has irreversible liver damage that would be fatal without a transplant.

2. The patient is in a condition where they can survive both the operation, post-operative period, and ongoing anti-rejection medications.

3. The patient will have a significant increase in quality of life and survival time following the transplant.

These criteria are decided by the Association for the Study of Liver Disease (AASLD).¹

Hepatocellular carcinoma 

Hepatocellular carcinoma is the fourth most common cause of cancer deaths worldwide. A liver transplant can be used to treat the underlying disease and remove the tumor. Around 15–50% of all liver transplants are for the treatment of hepatocellular carcinoma.²

However, because the number of organ donors is insufficient, patients are carefully selected for transplant based on their stage of liver damage and how beneficial a transplant would be. 

Patients eligible for liver transplants are prioritized on a system where the tumor characteristics, such as the size and number of tumors, as well as the waiting time, are taken into account.

In addition to these factors, the Milan criteria is typically used to select patients with hepatocellular carcinoma for a liver transplant.³

The Milan criteria was introduced in 1996 and is as follows:

1. Single tumor with a diameter of less than 5cm

2. No more than three foci of tumors, each must not exceed 3cm

3. No angioinvasion (i.e., no infiltration of blood vessels)

4. No extrahepatic involvement (i.e., the tumor activity is contained to the liver)

However, for children with hepatocellular carcinoma, the Milan criteria is not strictly followed.

Chronic liver failure

Chronic liver failure is sometimes referred to as end-stage liver disease and progressively worsens over time. Chronic liver failure is typically due to cirrhosis.⁴

Cirrhosis is a disease in which healthy liver tissue is replaced by scar tissue until liver failure occurs. A liver transplant is a good option for people with chronic liver failure. However, due to the lack of organ donors, waiting times are long. 

Liver transplants for chronic failure are considered when treatment is unable to control the complications that may arise from the disease.  

Acute liver failure

Acute liver failure is the rapid development of liver failure in an individual with no previous history of liver dysfunction. Acute liver failure is the reason for approximately 8% of liver transplants in both the United States and Europe.⁵ ⁶ ⁷

Acute liver failure has several causes, the most common being viral hepatitis infection. Drug-induced acute liver failure makes up approximately 50% of cases in developed countries, with one of the drugs causing these cases being paracetamol.

Before liver transplants were available as a surgery, acute liver failure had a high mortality rate. However, with liver transplants as an option, survival rates have been dramatically improved.

Liver transplant requirements

As mentioned earlier, patient selection for liver transplants is crucial to finding the best candidates based on their individual circumstances. 

In the US, the allocation of donor liver grafts to patients is based on waitlist mortality. Patients with the highest risk of mortality in the short term are offered transplants first. 

Patients on the waiting list for a liver transplant are given a Model for End-Stage Liver Disease-sodium (MELD-Na) score, which indicates how they should be prioritized. The MELD-Na score estimates the risk of death within 90 days without a transplant, with a higher score indicating a higher risk.⁸

However, some exceptions to this system exist. For patients with rapidly progressive liver disease who are given a time frame of hours to days to live if they don’t have a transplant, a status 1 listing is given. This means that they’re added to the top of the waiting list despite what their MELD-Na score may be.

Another exception to this scoring system occurs if a patient has a rare hepatic disorder in which the risk of them dying is not adequately captured by the MELD-Na score.

The Pediatric End-Stage Liver Disease (PELD) score is used for children younger than 12.

Liver donor requirements

Previously, all liver donors were deceased. However, as the need for more liver donations increased, the number of deceased liver donors became insufficient to supply everyone who needed a liver to survive. 

To keep up with patient needs, methods of using living donors for liver transplants were developed, as the liver can regenerate well within a healthy individual.

Several requirements need to be met in order for a healthy individual to donate a portion of their liver. These are:

• Must be between 18 and 60 years of age

• Must be in good physical shape

• Must have good mental health

• Must have a body mass index (BMI) less than 35%

• Needs to have a blood type compatible with the recipient of the liver

• Must not have any organs with a significant amount of disease

• Must not have cancer

• Must not have hepatitis

• Must not have any active infections or illnesses

• Must not have a chronic illness

• Must not abuse drugs or alcohol

Of note, it is illegal to sell or buy organs in the US, as such donations must be made voluntarily, and donors cannot be reimbursed monetarily. This is a result of the National Organ Transplant Act, which was passed by the US Congress in 1984.⁹

Life after a liver transplant

It can take a significant amount of time to recover from a liver transplant, but people typically have a much better quality of life following their transplant. 

Full recovery can take up to a year. However, typically after a few weeks, your activity can begin to return to normal. 

To ensure that your body accepts the liver donation, you need to take immunosuppressants. Unfortunately, these can cause side effects such as an increased risk of kidney problems, infections, and some types of cancer.

After you’ve been discharged from the hospital, you’ll likely have a series of regular follow-up appointments with your liver transplant team. These can be weekly, monthly, or only a couple of times a year, depending on how your recovery is progressing. 

While many factors affect survival, including the initial cause of liver disease, in general, 75% of patients who undergo liver transplants live for at least five years.

The lowdown

Liver transplants are used as a life-saving therapy for people with severe liver disease. Liver transplants are typically only performed on individuals who would not be able to survive without them. 

A significant shortage of livers from deceased donors exists, so liver transplants from living donors are becoming increasingly prevalent. In order to donate your liver, you must be in good health, and you must donate your liver voluntarily. Recovery from a liver transplant can take up to a year; however, quality of life is generally much improved afterward. 

Frequently asked questions

Why would someone need a liver transplant?

A person can have several reasons for needing a liver transplant. These include end-stage liver failure, acute liver failure, and hepatocellular carcinoma.

Where do donated livers come from?

Donated livers can come from both living and deceased donors. Because a shortage of deceased liver donors exists, and the demand for livers greatly outweighs the supply, living donor transplants are becoming more common. Liver transplants from living donors can occur due to the fast regeneration of the human liver if the donor is in good health. 

How does a person become a living liver donor?

Becoming a living liver donor involves a healthy volunteer having a part of their liver removed and grafted into the recipient. People can be living liver donors because the human liver can regenerate quickly. 

People who are interested in becoming living liver donors are required to meet a series of criteria to ensure that they are suitable candidates for donating their organs.