LIVER TRANSPLANTATION SURGERY
Category: General Surgery
Abstract : Liver transplantation Definition : Liver transplantation is a surgery that removes a diseased liver and replaces it with a healthy donor liver. Purpose : A liver transplant is needed when the liver’s function is reduced to the point that the life of the patient is threatened. Demographics : Compared to whites, those with African-American, Asian, Pacific Islander, or
Liver transplantation
Definition : Liver transplantation is a surgery that removes a diseased liver and replaces it with a healthy donor liver.
Purpose : A liver transplant is needed when the liver’s function is reduced to the point that the life of the patient is threatened.
Demographics : Compared to whites, those with African-American, Asian, Pacific Islander, or Hispanic descent are three times more likely to suffer from end-stage renal disease (ESRD). Both children and adults can suffer from liver failure and require a transplant. Patients with advanced heart and lung disease, who are human immunodeficiency virus (HIV) positive, and who abuse drugs and alcohol are poor candidates for liver transplantation. Their ability to survive the surgery and the difficult recovery period, as well as their longterm prognosis, is hindered by their conditions.
Description
The liver is the body’s principle chemical factory. It receives all nutrients, drugs, and toxins, which are absorbed from the intestines, and performs the final stages of digestion, converting food into energy and replacement parts for the body. The liver also filters the blood of all waste products, removes and detoxifies poisons, and excretes many of these into the bile. It further processes other chemicals for excretion by the kidneys. The liver is also an energy storage organ, converting food energy to a chemical called glycogen that can be rapidly converted to fuel.
When other medical treatment interferes with the functioning of a damaged liver, a transplant is necessary. Since 1963, when the first human liver transplant was performed, thousands more have been performed each year. Cirrhosis, a disease that kills healthy liver cells, replacing them with scar tissue, is the most common reason for liver transplantation in adults. The most frequent reason for transplantation in children is biliary atresia—a disease in which the ducts that carry bile out of the liver, are missing or damaged.
Included among the many causes of liver failure that bring patients to transplant surgery are:
• Progressive hepatitis, mostly due to virus infection, accounts for more than one-third of all liver transplants.
• Alcohol damage accounts for approximately 20% of transplants.
• Scarring, or abnormality of the biliary system, accounts for roughly another 20% of liver transplants.
• The remainder of transplants come from various cancers, uncommon diseases, and a disease known as fulminant liver failure.
Fulminant liver failure most commonly happens during acute viral hepatitis, but is also the result of mushroom poisoning by Amanita phalloides and toxic reactions to overdose of some medicines, such as acetaminophen— a medicine commonly used to relieve pain and reduce fever. The person who is the victim of mushroom poisoning is a special category of candidate for a liver transplant because of the speed of the disease and the immediate need for treatment.
As the liver fails, all of its functions diminish. Nutrition suffers, toxins build, and waste products accumulate. Scar tissue accumulates on the liver as the disease progresses. Blood flow is increasingly restricted in the portal vein, which carries blood from the stomach and abdominal organs to the liver. The resulting high blood pressure (hypertension) causes swelling of and bleeding from the blood vessels of the esophagus. Toxins build-up in the blood (liver encephalopathy), resulting in severe jaundice (yellowing of the skin and eyes), fluid accumulation in the abdomen (ascites), and deterioration of mental function. Eventually, death occurs.
There are three types of liver transplantation methods.
They include:
• Orthotopic transplantation, the replacement of a whole diseased liver with a healthy donor liver.
• Heterotrophic transplantation, the addition of a donor liver at another site, while the diseased liver is left intact.
• Reduced-size liver transplantation, the replacement of a whole diseased liver with a portion of a healthy donor liver. Reduced-size liver transplants are most often performed on children.
When an orthotropic transplantation is performed, a segment of the inferior vena cava (the body’s main vein to the heart) attached to the liver is taken from the donor, as well. The same parts are removed from the recipient and replaced by connecting the inferior vena cava, the hepatic artery, the portal vein, and the bile ducts.
When there is a possibility that the afflicted liver may recover, a heterotypic transplantation is performed. The donor liver is placed in a different site, but it still has to have the same connections. It is usually attached very close to the patient’s original liver; if the original liver recovers, the donor liver will wither away. If the patient’s original liver does not recover, that liver will dry up, leaving the donor in place.
Reduced-size liver transplantation puts part of a donor liver into a patient. A liver can actually be divided into eight pieces - each supplied by a different set of blood vessels. In the past, just two of these sections have been enough to save a patient suffering from liver failure, especially if it is a child. It is possible, therefore, to transplant one liver into at least two patients and to transplant part of a liver from a living donor - and for both the donor and recipients to survive. Liver tissue grows to accommodate its job provided that the organ is large enough initially. Patients have survived with only 15–20% of their original liver intact, assuming that that portion was healthy from the beginning.
As of 2003, the availability of organs for transplant was in crisis. In October 1997, a national distribution system was established that gives priority to patients who are most ill and in closest proximity to the donor livers. Livers, however, are available nationally. It is now possible to preserve a liver out of the body for 10 to 20 hours by flushing it with cooled solutions of special chemicals and nutrients, if necessary. This enables transport cross-country.
Description
Once a donor liver has been located and the patient is in the operating room and under general anesthesia, the patient’s heart and blood pressure are monitored. A long cut is made alongside of the ribs; sometimes, an upwards cut may also be made. When the liver is removed, four blood vessels that connect the liver to the rest of the body are cut and clamped shut. After getting the donor liver ready, the transplant surgeon connects these vessels to the donor vessels. A connection is made from the bile duct (a tube that drains the bile from the liver) of the donor liver to the bile duct of the liver of the patient’s bile duct. In some cases, a small piece of the intestine is connected to the new donor bile duct. This connection is called Roux-en-Y. The operation usually takes between six and eight hours; another two hours is spent preparing the patient for surgery. Therefore, a patient will likely be in the operating room for eight to 10 hours.
The United Network for Organ Sharing (UNOS) data indicates that patients in need of organ transplants outnumber available organs three to one.
Diagnosis / Preparation
The liver starts to fail only when more than half of it is damaged. Thus, once a person demonstrates symptoms of liver failure, there is not much liver function left.
Signs and symptoms of liver failure include:
• jaundice
• muscle wasting (loss of muscle)
• forgetfulness, confusion, or coma
• fatigue
• itching
• poor blood clotting
• build-up of fluid in the stomach (ascites)
• infections
• bleeding in the stomach
A doctor will diagnose liver disease; a liver specialist, a transplant surgeon, and other doctors will have to be consulted, as well, before a patient can be considered for a liver transplant. Before transplantation takes place, the patient is first determined to be a good candidate for transplantation by going through a rigorous medical examination. Blood tests, consultations, and x rays will be needed to determine if the patient is a good candidate. Other tests that may be conducted are: computed tomography (CAT or CT) scan, magnetic resonance image (MRI), ultrasound, routine chest x ray, endoscopy, sclerotherapy and rubber-band ligation, transjugular intrahepatic portosystemic shunt (TIPS), creatinine clearance, cardiac testing (echocardiogram [ECHO]) and/or electrocardiogram [EKG or ECG]), and pulmonary function test [PFTs]), liver biopsy, and nutritional evaluation. A dietitian will evaluate the patient’s nutritional needs and design an eating plan. Since a patient’s emotional state is as important as their physical state, a psychosocial evaluation will be administered.
Once test results are reviewed and given to the liver transplant selection committee, the patient will be assessed for whether he or she is an appropriate candidate. Some patients are deemed too healthy for a transplant and will be followed and retested at a later date if their liver gets worse. Other patients are determined to be too sick to survive a transplant. The committee will not approve a transplant for these patients. Once a patient is approved, they will be placed on a waiting list for a donor liver. When placed on the waiting list, a patient will be given a score based on the results of the blood tests. The higher a patient’s score, the sicker the patient is. This results in the patient earning a higher place on the waiting list.
Suitable candidates boost their nutritional intakes to ensure that they are as healthy as possible before surgery. Drugs are administered that will decrease organ rejection after surgery. The medical committee consults with the patient and family, if available, to explain the surgery and any potential complications. Many problems can arise during the waiting period. Medicines should be changed as needed, and blood tests should be done to assure a patient is in the best possible health for the transplant surgery. Psychological counseling during this period is recommended, as well.
When a donor is found, it is important that the transplant team be able to contact the patient. The patient awaiting the organ must not eat or drink anything from the moment the hospital calls. On the other hand, the liver may not be good enough for transplantation. Then, the operation will be cancelled, although this does not happen often.
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