Liver transplantation or hepatic transplantation is the replacement of a diseased liver with the healthy liver from another person (allograft). Liver transplantation is a treatment option for end-stage liver disease and acute liver failure, although availability of donor organs is a major limitation. The most common technique is orthotopic transplantation, in which the native liver is removed and replaced by the donor organ in the same anatomic position as the original liver. The surgical procedure is complex, requiring careful harvest of the donor organ and meticulous implantation into the recipient. Liver transplantation is highly regulated, and only performed at designated transplant medical centers by highly trained transplant physicians and supporting medical team. The duration of the surgery ranges from 4 to 18 hours depending on outcome. Favorable outcomes require careful screening for eligible recipient, as well as a well-calibrated live or cadaveric donor match.
Liver transplantation is a potential treatment for acute or chronic conditions which cause irreversible and severe ("end-stage") liver dysfunction. Since the procedure carries relatively high risks, is resource-intensive, and requires major life-modifications after surgery, it is reserved for dire circumstances. Judging the appropriateness/effectiveness of liver transplant on case-by-case basis is critically important (see Contraindications), as outcomes are highly variable.
Although liver transplatation is the most effective treatment for many forms of end-stage liver disease, the tremendous limitation in allograft availability and widely variable post-surgical outcomes make case selection critically important. Assessment of a person's transplant eligibility is made by a multi-disciplinary team that includes surgeons, medical doctors, and other providers.
The first step in evaluation is to determine whether the patient has irreversible liver-based diseased which will be cured by getting a new liver. Thus, those with diseases which are primarily based outside the liver or have spread beyond the liver are generally considered poor candidates. Some examples include:
- someone with advanced liver cancer, with known/likely spread beyond the liver
- active alcohol/substance abuse
- severe heart/lung disease
- existing high cholesterol levels in the patient
Importantly, many contraindications to liver transplantation are considered reversible; a person initially deemed "transplant-ineligible" may later become a favorable candidate if their situation changes. Some examples include:
- partial treatment of liver cancer, such that risk of spread beyond liver is decreased
- cessation of substance abuse (time period of abstinence is variable)
- improvement in heart function, e.g. by percutaneous coronary intervention or bypass surgery
- treated HIV infection
Before transplantation, liver-support therapy might be indicated (bridging-to-transplantation). Artificial liver support like liver dialysis or bioartificial liver support concepts are currently under preclinical and clinical evaluation. Virtually all liver transplants are done in an orthotopic fashion; that is, the native liver is removed and the new liver is placed in the same anatomic location. The transplant operation can be conceptualized as consisting of the hepatectomy (liver removal) phase, the anhepatic (no liver) phase, and the postimplantation phase. The operation is done through a large incision in the upper abdomen. The hepatectomy involves division of all ligamentous attachments to the liver, as well as the common bile duct, hepatic artery, hepatic vein and portal vein. Usually, the retrohepatic portion of the inferior vena cava is removed along with the liver, although an alternative technique preserves the recipient's vena cava ("piggyback" technique).
All donors are assessed medically to ensure that they can undergo the surgery. Blood type of the donor and recipient must be compatible but not always identical. Other things assessed prior to surgery include the anatomy of the donor liver. However, even with mild variations in blood vessels and bile duct, surgeons today are able to perform transplantation without problems. The most important criterion for a living liver donor is to be in excellent health.