Liver transplantation is a surgery in which the diseased liver is removed and replaced with a healthy one. Cirrhosis of the liver is the commonest indication for a liver transplant. Other indications include liver cancer, acute liver failure of genetic diseases. Liver failure can be acute (one that can happen in a short period of time) or chronic (which can occur over a longer period of time). Across the world, there are thousands of patients who have had a liver transplant and are now leading normal lives.
Liver damage can occur suddenly or it can happen over a prolonged period due to various causes:
Sudden or Acute Liver Failure
Chronic (Long term) Liver Failure
In children, the liver can be damaged due to a condition called ‘Biliary Atresia’ and some other metabolic disorders and liver tumours.
Some of the important signs of liver failure are as follows:
The team at our hospital will examine you and evaluate all your blood and radiological results. Based on their assessment, they will recommend a liver transplant if it is required.
If a transplant is not deemed suitable or not required, they will treat you with the necessary medications.
If you do need a liver transplant, other aspects of your health including the condition of your heart, lungs and kidneys will be assessed.
There are two types of transplant
a) Cadaveric liver transplant
In these cases, the liver is harvested from a brain dead person whose heart is still working. Such a person is legally considered dead, but as long as the rest of his organs are well, they can be transplanted to the patient.
b) Living donor liver transplant (LDLT)
A healthy person from the patient’s family donates a part of his/her liver. This donor is called a ‘living donor’. The donors undergo a thorough and detailed evaluation of their health. Liver is the only solid organ that has a capacity to regrow and regenerate when it is cut, thus, making LDLT a realistic option.
In Asian countries including India, 90% of liver transplant are of the Living Donor Type. Safety and advances in liver surgery has enabled successful implementation of LDLT.
Blood group should be identical or compatible to the patient’s blood group. Positive or negative does not matter. Also, ‘O’ blood group people are universal donors and people with ‘AB’ blood group are universal recipients.
For eg: A patient of ‘A’ blood group (positive or negative) can receive a liver from either ‘O’ or ‘A’ group (positive or negative). A patient whose blood group is ‘AB’ can receive a liver from anybody.
It has been estimated that about 2, 00,000 deaths occur due to liver failure in India every year, of which many would be candidates for a life-saving liver transplant. The actual number of liver transplants performed in India is about 1200 a year- a minute fraction of the real requirement.
In this group of patients, timely referral is crucial. A delay in referral results in a sick patient, whose capacity to survive a major operation has been seriously compromised because, besides liver, even other organs have been severely damaged. The indications for liver transplantation may be divided into the following categories:
1. Chronic liver disease (cirrhosis)
This is the most common indication for liver transplantation. Cirrhosis, by itself, is not an indication for liver transplant but decompensated cirrhosis is. Complications of cirrhosis include ascites, encephalopathy, gastrointestinal bleeding (typically from gastro-esophageal varices), renal dysfunction (hepatorenal syndrome) and pulmonary problems (hepatic hydrothorax and hepatopulmonary syndrome).
The risk of mortality within one year in a patient with ascites and varices is about 20% and in a patient with ascites, who has had a variceal bleed is nearly 60%. A patient with even a single episode of spontaneous bacterial peritonitis has a one year mortality risk of 50%. There are scores to calculate the risk of mortality in patients with cirrhosis.
The Childs-Turcotte-Pugh (CTP) score would be familiar to everyone. It is based on five parameters: serum bilirubin, serum albumin, INR (International Normalized Ratio of Prothrombin Time), severity of ascites and severity of encephalopathy. Each of these parameters is given a score of 1-3. The normal CTP score is 5 and the highest possible is 15. Anyone with a CTP score of 10 or more should be referred for a transplant. The three-month mortality risk for a patient with this CTP score is over 50%. Another score used to assess risk of mortality is the Model for End Stage Liver Disease (MELD). This requires only the bilirubin, creatinine and INR. Patients with a MELD score of 15 or more need a liver transplant.
2. Acute liver failure (Fulminant Hepatic Failure)
This occurs when a toxic attack on the liver causes death of most of the liver cells. In the West, the commonest cause of FHF is paracetamol overdose. In India, the common causes are hepatitis B, hepatitis A, hepatitis E and some drugs, such as those used to treat tuberculosis. Jaundice, encephalopathy and coagulopathy are the indicators of a failing liver and a patient with hepatitis who becomes drowsy or confused or who has coagulopathy (an INR of more than 2), should be referred for an emergency liver transplant. These patients can deteriorate very rapidly (within a matter or hours) due to cerebral edema. If transplanted on time they do very well because they are usually otherwise healthy and often young and have not been debilitated by long standing chronic liver disease.
3. Liver cancer
Primary liver cancer often occurs in a liver which is already cirrhotic and this limits the treatment options. In a normal liver, a large part of the liver can be resected in order to remove tumor (up to 75%) with the knowledge that the liver has enough reserve, not only to continue functioning but also to regenerate and rapidly grow back to its full size. In a cirrhotic liver, however, this reserve as well as capacity to regenerate is lost and a safe liver resection is not possible. In this situation a liver transplant is life-saving provided there is no spread outside the liver or invasion of the major blood vessels of the liver.
4. Rarer causes
There are many rarer diseases which require a liver transplant such as hepatic venous obstruction which progresses to cirrhosis, biliary atresia in babies (treated unsuccessfully or too late) or genetic disorders (Wilson’s disease, Crigler Najjar Syndrome, etc.).
The liver transplant operation
While planning a Living Donor Liver Transplant (LDLT), it is vital of explain to the family who can donate. Every living donor liver transplant has to be authorized by a committee. It is the committee’s responsibility, as well as the treating physicians, to ensure that no one is paid or coerced to donate. For practical purposes, this is impossible to establish unless the donor is a relative of the patient. The blood group of the donor must be compatible with that of the patient.
The following combinations are feasible:
|A||O or A|
|B||O or B|
|AB||O, A, B, AB|
From the above table, it is clear that ‘O’ blood group people are universal donors & ‘AB’ blood group people are universal recipients.
After establishing that the blood groups are compatible, a detailed history and physical examination is performed to establish that the donor does not have a medical condition that would increase the risk of surgery. For example, mild hypertension controlled with a single antihypertensive or with a low salt diet would not be a contraindication but sustained hypertension with a hypertrophied left ventricle and peripheral vascular disease would be. Similarly early diabetes controlled with diet, exercise and perhaps an oral hypoglycemic drug would not be a problem but long standing diabetes with retinopathy and nephropathy would be.
Next some basic blood tests are done. These include confirmation of the blood group, blood counts, liver and kidney function tests and tests for hepatitis B and C and HIV. A CT scan of the abdomen without contrast is done next. The LAI (Liver Attenuation Index) is used to estimate the extent of steatosis in the liver. If the CT shows a normal liver, we proceed to perform a contrast enhanced triphasic CT of the liver. This allows us to measure the liver (CT volumetry is done using specialized software). This allows us to decide which part of the liver to remove for transplant. As a general rule, the portion of the liver transplanted should be at least 0.8% of the body weight of the patient and the portion left behind should be at least 30% of the original liver volume. It is normally safe to remove up to 75% of the liver but we keep a margin of safety for the donor. The triphasic CT also demonstrates the vascular anatomy of the liver nicely and allows us to assess that the operation can be safely done leaving both the graft and the remnant with an arterial and portal venous supply, good venous drainage and bile duct suitable for reconstruction.
Subsequent tests are performed to assess the fitness of the donor to undergo surgery safely. This includes assessment by a Cardiologist, Pulmonologist, Psychiatrist, Gynecologist (for female donors), Hepatologist and Anesthetist. A multidisciplinary meeting is held and once there is unanimity regarding the need for transplant and the safety of the operation for patient and donor, the request for permission to perform the transplant is submitted to the authorization committee.
The patient is admitted 2 days before the transplant (if not already admitted) and the donor, the day before the transplant.
The donor surgery takes about 4-6 hours and involves resecting the right lobe with its vital structures (the right hepatic artery, right portal vein, right hepatic duct , right hepatic vein and in majority of the cases the middle hepatic vein). All the structures are looped and kept ready to cut in order to proceed with right lobe donation.
At the same time, the recipient team will remove the entire diseased liver and preserve the vital structures. (The right and left hepatic artery, main portal vein, the openings of the right, middle and left hepatic veins and the common hepatic duct). Once both the teams are ready, the donor liver (right lobe) is removed. It is then flushed with cold preservative solution and the structures are re-constructed on the ‘backbench”. It is packed in ice. This is the beginning of the cold ischaemia time.
Once the recipient liver (diseased) liver is out, the rejoining process of the donor right lobe structure to the recipient structures is commenced. It takes about 30- 60 mins for this procedure .The donor liver is removed from the ice bag. (end of cold ischaemia and beginning of warm ischaemia phase) The donor RHV and MHV is connected to patient inferior vena cava; the donor right portal vein to patients main portal vein. At this stage blood circulation is re-commenced via the portal vein (end of warm ischaemia phase). The artery and bile duct is then re-constructed.
Both the recipient and the donor are shifted to the Intensive care unit (ICU). The donor is admitted to ICU for 1 day and then shifted to the wards for 4-5 days. (average stay for donor is 5-7 days)
The recipient stays in the ICU for 4-5 days and then shifted to the wards for 5-13 days. (average stay for recipient is 10-21 days)
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