What Is A Liver Transplant? Why And How Is A Liver Transplant Performed?

What is a Liver Transplant?

Liver transplantation is a medical surgical procedure in which a liver that is no longer functioning properly due to chronic liver failure is removed and replaced with a healthy liver obtained from a donor. In this procedure, the damaged or non-functioning liver is removed and replaced with a healthy liver obtained from a donor.

Liver transplantation can be performed using an organ obtained from a deceased donor or a living donor. Factors such as the patient's general health and organ compatibility affect the success of the transplant process. Liver transplantation offers an effective solution for improving patients' quality of life and preventing long-term health problems.

The liver is the body's largest internal organ, located in the upper right abdomen, just below the diaphragm. It performs vital functions such as purifying the blood, eliminating toxins, storing energy and producing clotting factors.

These critical functions of the liver can threaten the patient's life in the event of serious liver disease. Liver transplantation is the process of replacing a liver that has irreversibly lost its function with a healthy liver, and this procedure is performed by specialist teams at liver transplant centres.

Liver transplantation, typically performed in cases of end-stage liver disease or acute liver failure, is vital for the patient's survival and improved quality of life. The central role of the liver clearly demonstrates why transplantation is such an important and complex medical procedure.

In Which Diseases is Liver Transplantation Performed?

Liver transplantation is generally performed in serious conditions such as liver failure, cirrhosis, chronic liver diseases such as hepatitis B and C, congenital metabolic disorders, or liver tumours. In liver transplant procedures, diseases such as cirrhosis, primary biliary cirrhosis, and primary sclerosing cholangitis are among the reasons requiring transplantation.

In addition, liver transplantation is also preferred as a life-saving treatment in emergency situations such as acute liver failure that develops suddenly.

Conditions that may require a liver transplant can be listed as follows:

• Chronic liver failure
• Acute liver failure
• Alcoholic liver disease
• Hepatitis B and Hepatitis C
• Primary biliary cirrhosis or primary sclerosing cholangitis
• Autoimmune hepatitis
• Liver tumours
• Congenital metabolic disorders
• Biliary tract anomalies
• Drug- or toxin-induced liver damage

Liver transplant assessment

The liver transplant evaluation process involves the transplant team determining the risk factors for each patient through detailed examination and laboratory tests. Transplantation is generally possible except in cases of incurable cancer and infectious diseases, refusal of treatment, psychiatric problems or mental incapacity.

A candidate requiring a liver transplant should have a reasonable life expectancy, be able to tolerate surgical procedures, and possess sufficient organ reserve to withstand the effects of immunosuppressive drugs.

Although the age limit for liver transplantation is generally 65, the patient's general condition is a more important criterion than their age. For patients diagnosed with end-stage liver disease, a recipient assessment lasting approximately 5-7 days and carried out in three phases is recommended.

The criteria for liver transplantation are generally as follows:

• Diagnosis of acute or chronic liver failure
• Model for End-Stage Liver Disease (MELD) score ≥15 and/or severe liver dysfunction
• The patient has no other serious and irreversible illnesses.
• Alcohol and substance abuse being under control
• A good social support system and positive results from psychosocial assessment
• The ability to comply with medication and follow-up after a liver transplant

Other systems such as the heart, lungs, kidneys and blood counts are tested and the presence of infection is ruled out. The liver specialist then decides how successful the operation is likely to be, based on the patient's condition and the cause and severity of the liver disease.

The final stage requires the patient to be psychologically and mentally prepared. The patient and their family are informed about the procedure, hospital stay, the likely course of events following surgery, follow-up care, and post-operative care.

Following liver transplant evaluation, the patient is placed on the waiting list for a cadaveric transplant or, if there is a willing and blood-type-matched relative, the person is evaluated for donation and the transplant is planned.

Patients placed on the waiting list for cadaveric transplantation are monitored by the transplant team until a suitable liver is found. If the patient's condition shows signs of deterioration, we generally recommend that the family consider living liver donation.

Diseases Evaluated In The Recipient

The recipient's health status should be comprehensively assessed prior to the transplant operation. Coronary artery disease should be carefully considered due to the high morbidity and mortality risk associated with cardiovascular diseases.

Angiography should be performed on symptomatic patients, non-invasive cardiac tests should be performed on asymptomatic patients in the high-risk group, and if necessary, they should be made suitable for bypass surgery.

In individuals with chronic lung disease, measures should be taken against the risk of post-operative infection when assessing whether current lung function is suitable for surgery. In patients with a history of malignant disease, complete recovery from the disease is a prerequisite for transplantation.

Depending on the type of cancer, waiting times can vary between 2 and 5 years. Furthermore, active infections are a contraindication for transplantation, and a detailed screening should be carried out for infections such as HIV, tuberculosis and cytomegalovirus.

Approaches to organ transplantation in HIV-positive patients have begun to change thanks to modern antiretroviral treatments, but the risks of post-operative complications are taken into account.

• Coronary artery disease: Angiography is performed in symptomatic patients; non-invasive cardiac tests are performed in asymptomatic, high-risk patients.
• Cardiovascular diseases: These are carefully assessed due to the high risk of morbidity and mortality.
• Chronic lung diseases: An assessment is made as to whether lung function is adequate for surgery.
• History of malignant disease: Proof that the disease has completely resolved is required; the waiting period varies between 2 and 5 years depending on the type of cancer.
• Active infections: Infections such as HIV, tuberculosis, and cytomegalovirus are screened for, and active infections are considered contraindications.
• HIV positivity: Transplantation is possible with modern antiretroviral treatments, but the risks of complications are assessed.
• Risk of post-operative infection: Detailed examination and precautions are required, particularly in individuals with chronic lung disease.

Laboratory investigations

Comprehensive laboratory tests are performed for pre-liver transplant evaluation. Blood and urine tests include haematological analyses, kidney and liver function tests, hepatitis and viral serology, and tumour markers.

Cardiological assessment is performed using ECG, echocardiography and, if necessary, coronary angiography. Radiological examinations such as chest X-rays and blood gas analysis are completed; endoscopic examinations are also performed when necessary.

Computed tomography is used as the primary imaging method, while PET scans, scintigraphy and thrombosis tendency tests are performed in specific cases. Consultations are requested from various departments such as chest diseases, cardiology, anaesthesia, dentistry, psychiatry, gastroenterology and infectious diseases, and all relevant tests are added.

• Blood and Urine Tests: Haematological tests, kidney and liver function tests, hepatitis markers, viral serology (CMV, EBV, etc.), tumour markers, fasting blood sugar, uric acid, calcium and phosphate levels, and urine analysis are performed.
• Electrocardiogram and Echocardiography: Heart function is assessed, coronary angiography is performed if necessary, and all cultures are taken to confirm that no infectious agent is present.
• Radiological Investigations: A chest X-ray is taken, blood gas analysis is performed, and endoscopic investigations are carried out when necessary (oesophagus, stomach, duodenum and colon).
• Other Investigations: Computed tomography is requested; if necessary, PET, scintigraphy and thrombosis tendency tests are performed, multidisciplinary consultations and relevant additional investigations are completed.

Preparation Before Liver Transplant Surgery

As is well known, blood group compatibility is important. Blood group incompatible transplants are also performed, but these have not been as successful as transplants between AB0 compatible groups.

Donors who have completed all tests are admitted to hospital 2-3 days before surgery. A detailed history (including personal and family history) is taken and a thorough physical examination is performed. A complete physical examination must be carried out systematically, ensuring that no system is overlooked.

During this examination, consultation with specialists in relevant fields should be sought for conditions requiring specific examination and assessment, such as ear, nose and throat, dental, gynaecological, cardiological, and chest diseases. Previously performed tests, such as complete blood count, urine test, ECG, chest X-ray, and blood biochemistry, are repeated.

Cytomegalovirus titration should be re-performed and checked. Two units of blood should be prepared according to the blood group. The donor must sign the consent form before the operation. It is advisable for the donor to wash the day before the operation.

The donor is kept fasting from 10 to 12 hours prior to the scheduled surgery time. During this period, 1000 ml of Lactated Ringer's solution is administered via infusion. Elastic bandages are applied to the lower extremities.

Laboratory tests performed on the donor

During the liver transplant process, numerous laboratory tests are performed to assess the suitability of the donor. These tests are conducted to determine the donor's overall health, infection carrier status, organ function, and tissue compatibility. In addition, the functionality, structural integrity, and suitability of the liver for the recipient without causing harm are also investigated in detail.

The main laboratory tests performed on donors for liver transplantation are as follows:

• Blood typing (for ABO and Rh compatibility)
• Complete blood count (hemoglobin, hematocrit, platelet, etc. levels)
• Liver function tests (AST, ALT, ALP, GGT, bilirubin levels)
• Kidney function tests (urea, creatinine)
• Coagulation tests (PT, aPTT, INR)
• Viral serologies (HBsAg, Anti-HBc, Anti-HCV, Anti-HIV)
• Infection screenings (CMV, EBV, Syphilis, Toxoplasma, etc.)
• Blood sugar and electrolyte levels
• Tissue typing and HLA compatibility assessment
• Blood cultures (especially in intensive care donors)

How is Liver Transplantation Performed?

Liver transplantation is generally performed in serious cases such as cirrhosis, hepatitis B or C, liver cancer, and metabolic liver diseases. Because liver dysfunction poses a life-threatening risk, this procedure is lifesaving for many patients. The need for a transplant is determined by the patient's general condition and liver function tests.

Before the transplant, both the donor and recipient undergo a comprehensive evaluation process. The recipient is assessed for infection, cancer, or serious systemic diseases. For living donors, liver health, tissue compatibility, and psychological compatibility are checked. Ethics committee approval is also required during this process.

After the transplant, patients must take immunosuppressive medications for life. These medications prevent the body from rejecting the new liver. However, this can make the patient more vulnerable to infections. Regular follow-up and lifestyle changes increase the chance of success.

While liver transplantation is a complex surgical procedure, success rates are quite high in experienced centers. World-class practices are implemented in living donor transplants, especially in Türkiye. Appropriate center selection and multidisciplinary care are the most important factors determining long-term outcomes.

Left Half of the Liver

In a liver transplant, the ligaments holding the liver in place are first cut. A cholecystectomy is then performed, and intraoperative radiographs are taken to reveal the anatomy of the bile ducts. Following this, the vessels supplying the left lobe and the bile duct are exposed and suspended.

The suspended vessels are closed, and the area supplied by these vessels is determined. The structures supplying the right side of the liver are carefully preserved. The liver tissue is dissected in the midline, 2 cm to the right of the ligament suspending the liver.

After the liver capsule is cut with cautery, the parenchyma is separated using an ultrasonic tissue dissector and radiofrequency. The resulting vascular structures are controlled with clips, free ligation, or sutures. During transection, vascular control is usually not exercised, and arterial and portal blood continues to drain into the liver via the hepatic veins.

The bile ducts are isolated within the parenchyma and sectioned. The distal end is carefully sutured, leaving the proximal end open to visualize the biliary drainage. The left portal vein, left hepatic artery, and left hepatic vein are clamped and divided sequentially. Depending on the amount of liver required, all or part of the left lobe may be removed.

Right Half of the Liver

The favorable results observed in children with the removal of the left half of the liver have led to the idea that a similar procedure can be applied to the right lobe in adults. The advantage of this graft (segments 5-6-7-8) is that it fits perfectly into the space on the right side.

Disadvantages are a large cross-sectional area and vascular and bile duct anomalies. In the absence of an accessory artery, the right hepatic artery is generally a large artery. Venous drainage is characteristic and adequate liver drainage must be ensured with a wide anastomosis.

In the presence of a large second hepatic vein (inferior right hepatic vein), two separate anastomoses must be made or their mouths must be connected with artificial or specially preserved veins. For the bile ducts, one or more anastomoses to the intestine or the recipient's own bile ducts may be required, depending on the number of ducts.

The most important issues in adult liver transplantation are the maximum number of grafts that can be taken without putting the donor at risk and the minimum graft volume required for the recipient to survive.

Although the minimum adequate graft volume is unknown, a graft-to-body weight ratio of 1% or more or transplantation of 50%-60% of the estimated graft weight is thought to be sufficient.

The extended right lobe, which includes the middle hepatic vein but not the entire segment 4, greatly reduces the likelihood of graft failure for the recipient. However, since 2/3 of the liver is removed in this method, which requires major surgery, liver dysfunction is more common in the donor.

Cadaveric Liver Transplantation

The positive results observed in children using the left half of the liver have led to the idea that a similar procedure could be performed in adults using the right lobe. This graft (segments 5-6-7-8) fits perfectly into the space on the right side.

The right hepatic artery is usually a large artery unless there is an accessory artery. Venous drainage is characteristic and adequate liver drainage must be ensured with a wide anastomosis.

In the presence of a large second hepatic vein (inferior right hepatic vein), two separate anastomoses must be made or their mouths must be connected with artificial or specially preserved veins. For the bile ducts, one or more anastomoses to the intestine or the recipient's own bile ducts may be required, depending on the number of ducts.

The most important issues in adult liver transplantation are the maximum number of grafts that can be taken without putting the donor at risk and the minimum graft volume required for the recipient to survive.

Although the minimum adequate graft volume is unknown, a graft-to-body weight ratio of 1% or more or transplantation of 50%–60% of the estimated graft weight is considered sufficient.

The extended right lobe, which includes the middle hepatic vein but not the entire segment 4, greatly reduces the likelihood of graft failure for the recipient. However, since 2/3 of the liver is removed in this method, which requires major surgery, liver dysfunction is more common in the donor.

Back-Table (Preparing the Received Liver for Transplantation)

When removing a liver from a donor (cadaver or living donor), the liver, along with surrounding tissues, is removed in a sterile and cold environment. The liver is then cleaned of excess tissue and prepared for transplantation. On a completely sterile operating table, a bag containing the liver is placed inside a container filled with crushed sterile ice and cold serum, containing special solutions. This prevents other liquids and ice from entering the bag. This allows the liver to be prepared without removing it from the cold liquid environment. To this end, the veins and bile ducts are prepared, cleaned of surrounding tissue, and any punctures or injuries to the veins are identified and repaired. Patches are applied if necessary.

Transplanting the Liver to the Recipient

Mersedes incision is made in the recipient's abdomen, extending both to the right and left under the ribs and also extending to the midline. The liver is removed entirely above the great vein, preserving the hepatic vein and bile duct stumps.

A Before the liver is brought to the operating room, it is important to ensure that the vascular stumps and surgical field are prepared. The liver is first sutured to the main vein. The infrahepatic vena cava, which has been sutured in two rows, is brought to the liver area and sutured to the junction of the suprahepatic vena cava and hepatic veins.

The vessels that supply blood to the liver are then sutured to the recipient's vessels. At the completion of the anastomosis, the clamps on the vessels are removed. In patients with vascular problems, vein grafts (synthetic or autologous vein grafts taken from both the recipient and the donor) can be placed between them.

Arterial anastomoses are performed between similar arteries in both the recipient and the donor. Sometimes the splenic artery can be used for this purpose. If the recipient's artery is compromised, the liver artery can be connected directly to the main artery using veins taken from the recipient or donor, or synthetic vessels.

This procedure is performed under a microscope if necessary. The bile duct can then be sutured to the recipient's bile duct or intestine. A stent or T-tube may be used in this situation. If a drainage tube was used, it can be removed from the abdominal wall. After bleeding is controlled, drains are placed, and the abdomen is closed.

Cadaveric Donor Liver Transplantation

This type of transplant is performed on individuals who have donated organs during their lifetime or who have experienced brain death and whose family wishes to donate their organs. This occurs in patients who have been admitted to intensive care after suffering brain damage due to an accident or illness.

After the patient's death (brain death) is definitively determined, the family is consulted. After consent for organ donation is obtained, some of the donor's organs and the entire liver can be used for transplantation to other patients.

Following removal, the liver is safely stored outside the body in special preservation solutions for 1 to 15 hours. During this period, studies in integration with the National Coordination System (UKS) determine the most suitable recipients, and the liver is then sent to the appropriate center.

Living Donor Liver Transplantation

This type of transplant is performed on living donors who are not legally or healthily prohibited from having a portion of their liver removed. For this procedure to be performed, the donor and recipient must be related by blood or blood relatives up to the fourth degree.

In cases where there is no consanguinity but a long-term acquaintance or friendship, approval must be obtained from ethics committees established within the Health Directorates to assess the situation.

Due to advancing technology and a better understanding of liver anatomy, donor transplantation can now be performed safely. In healthy individuals, due to the large reserves of the liver, even a 70% liver transplant can meet the donor's metabolic needs. The liver regenerates rapidly in both the donor and the recipient within a few weeks, reaching nearly normal size after an average of one month.

Post-Liver Transplantation

The post-liver transplantation period requires meticulous monitoring to ensure the patient's recovery and the transplanted organ's adaptation. The patient is closely monitored in the intensive care unit to assess the transplanted liver's functions and identify potential complications early.

To reduce the risk of rejection, immunosuppressive medications are regularly administered, and the side effects of these medications are monitored. Because the risk of infection is high, appropriate preventive measures are implemented, and the patient's general health is monitored with regular blood tests.

Diet, physical activity, and lifestyle changes are important for the long-term health of the liver. Regular post-transplant checkups are crucial for preventing potential complications and maintaining overall health.

What are the Requirements for Liver Donation?

For living donor liver donation, the donor must donate of their own free will and be over 18 years of age. The donor must be related to the recipient up to the fourth degree, and a blood type match must be ensured.

Furthermore, the donor's liver structure and functions must be normal, there must be no other health problems in their systems, and the liver anatomy must be suitable for both the recipient and themselves.

The evaluation of these conditions and other technical suitability is usually carried out in detail by the transplant team during the pre-transplant evaluation, which takes 2-3 days.

Liver donation conditions can be listed as follows:

• The donor must make the donation of their own free will.
• The donor must be over 18 years of age.
• The donor must be a relative up to the fourth degree.
• The donor and recipient must have matching blood types.
• The donor's liver structure and function, as well as other systems, must be normal.
• The anatomy of the donor's liver must be suitable for the recipient and the donor themselves.

Frequently Asked Questions About Liver Transplantation

What is a liver transplant procedure?

Who is a candidate for a liver transplant?

How long does a liver transplant take?

Who can be a donor for liver transplantation?

What is the recovery process like after a liver transplant?

Is it necessary to use medication after liver transplantation?

Is living donor liver transplantation possible?

Is a liver transplant life-saving?