What is the liver?
Liver plays an important role in the normal functioning of the body. It is the largest solid internal organ in the body, and it weighs about 1.36 to 1.59 kilograms. Apart from various important functions, the primary functions of the liver include eliminating toxins from the blood and producing bile.
Structure of liver – anatomy, and microscopy
Liver is present on the right side of your body and is protected by the rib cage. It has two lobes – the larger right lobe and the smaller left lobe. Blood supply to the liver is maintained by the portal
vein and hepatic artery. All the nutrients that are absorbed by the digestion of food reach the liver through the portal vein. The filtered blood is drained from the liver through the hepatic veins and reaches the heart through the vena cava. The anatomical position of the liver is the body along with its parts is shown in the diagram below. The gall bladder is closely related to the liver. The bile fluid which is produced in the liver is stored in the gall bladder and is poured into the intestine during food digestion. Bile fluid reaches the gall bladder through bile ducts, hepatic ducts, and reach the intestines through the common bile duct. The microscopic picture of the liver is also shown in the figure below (Visual Representation) –
What tests are done to assess the function of the liver?
Various blood tests are done to look at the functioning of the liver. There are also many imaging tests to look at the structural changes in the liver due to a disease.
The most common blood test used to assess the liver is a panel of blood tests – Liver function test (LFT).
LFT incorporates estimation of serum proteins, Albumin, Bilirubin, enzymes like Alanine transaminase (ALT), Aspartate transaminase (AST), Alkaline phosphatase (ALP), and Gamma-glutamyl transferase (GGT). Derangements of each of the above parameters lead doctors to some differential diagnosis. Apart from LFT, L-lactate dehydrogenase (LD), Prothrombin time (PT), Complete blood tests (CBC)also aid in assessing liver function. Hepatitis markers like Hepatitis A, Hepatitis B, Hepatitis C, Hepatitis E, and Hepatitis D are available to identify the cause of liver disease if any. Liver biopsy is the gold standard in the diagnosis of any intrinsic liver disease.
Radiological examinations like an ultrasound of the abdomen, CT scan, MRI, MRCP help doctors to investigate and stage the liver disease.
What is liver fibrosis? What are its causes and stages?
Any injury or inflammation in the liver causes damage to the liver architecture and can lead to liver fibrosis (liver scarring). Unless the cause of the injury is ascertained and treated, fibrosis of the liver progresses to severe stages and can lead to irreversible cirrhosis stage. Common causes of liver fibrosis are non-alcoholic fatty liver disease (NAFLD), which is a lifestyle-related disease, and alcoholic liver disease, which results from excessive consumption of alcohol.
Liver fibrosis can also be caused by viral hepatitis – hepatitis B & C, Autoimmune hepatitis, Iron overload, etc.
Liver fibrosis can progress in stages from F1 to F4 where the liver progressively becomes firmer and harder.
F0: No fibrosis
F1: Portal fibrosis with no septa
F2: Portal fibrosis with few septa
F3: Numerous septa without cirrhosis
What is liver cirrhosis? What are its causes and stages?
Fibrosis, if not treated adequately and on time, further progresses to cirrhosis. In advanced liver cirrhosis, the liver generally shrinks in size and assumes nodular margins instead of smooth margins, and also can harbor cancer spots. Many diseases and conditions can cause liver cirrhosis. If it is in advanced stages, the condition cannot be reversed. Some of the conditions that lead to liver cirrhosis are:
Chronic alcohol abuse
Chronic viral hepatitis (hepatitis B, C, and D)
Non-alcoholic fatty liver disease
Liver disease caused by your body’s immune system (autoimmune hepatitis)
Iron builds up in the body (hemochromatosis)
Copper accumulation in the liver (Wilson’s disease)
Poorly formed bile ducts (biliary atresia)
Alpha-1 antitrypsin deficiency
Inherited disorders of sugar metabolism (galactosemia or glycogen storage disease)
Genetic digestive disorder (Alagille syndrome)
Destruction of the bile ducts (primary biliary cirrhosis)
Hardening and scarring of the bile ducts (primary sclerosing cholangitis)
Infection, such as syphilis or brucellosis
Medications, including methotrexate or isoniazid.
Cirrhosis of the liver can present as
Compensated cirrhosis: This stage is generally devoid of any symptoms. The liver is still able to do its job because it has healthy cells in reserve. A person with compensated cirrhosis can be in this stage for years.
Decompensated cirrhosis: In this stage, the liver has too much scarring and develops complications characterized by jaundice, fluid build-up in the belly (ascites), and enlarged and bleeding blood vessels.
Hepatic encephalopathy is a state in which toxins build up in a person’s brain and makes them confused/extremely tired.
Liver cirrhosis can further lead to impairment of kidneys known as a hepatorenal syndrome, and impairment of lungs called hepato-pulmonary syndrome and can also lead to liver cancer.
What is albumin? What are the uses of albumin in treating liver diseases?
Serum albumin is a major large-sized protein found in human blood and is primarily produced in the liver. It is one of the most abundant proteins in the plasma. Albumin in the blood plays an important role in the transportation of toxins, drugs, and metabolites. The amount of albumin can reduce in the blood in diseases of the liver, kidney, and malnourished conditions.
Infusion of human Albumin into the blood is now widely used to treat many conditions. It is mainly used in liver cirrhosis and its complications like the infection of water in the belly. It is found to improve circulatory and renal functions.
What is jaundice?
Jaundice is a condition that arises from too much bilirubin in the blood. It causes yellowish discoloration of a person’s eyes and skin. This is most commonly seen in people with liver disease.
What is ascites?
Excessive fluid accumulation in the belly is called ascites and the accumulated fluid is called ascitic fluid. Ascites are caused mainly by liver cirrhosis but also can be due to heart and kidney diseases. Tuberculosis infection can also cause ascites. People with ascites can have nausea, fatigue, breathlessness and it makes a person quite uncomfortable. The specific cause of ascites can be ascertained by an analysis of ascitic fluid and by other investigations. Based on the results and cause of ascites, treatment is initiated.
What are varices?
Varices are enlarged or swollen blood vessels. Common places in the body where varices can be seen are the lower end of the food pipe (esophagus), stomach, and rectum. Varices are normally seen in advanced liver disease due to alteration in the flow of blood. The major risk these varices pose is bleeding which can be life-threatening if not stopped adequately. Doctors hence advise appropriate screening for varices in patients with liver disease.
What is hepatic encephalopathy?
An important function of the liver is to filter out toxins from the blood. When the liver doesn’t function properly, the toxins get mixed into the blood and eventually end up in the brain. This causes confusion and fatigue and prevents a person from doing even regular household work. This is a very dangerous situation since the patient may not be oriented in what they are doing and in severe cases can slip into a coma. This state is called hepatic encephalopathy.
What is GI bleeding in patients with liver diseases?
Vomiting of blood or passing black-colored stools can be seen in patients suffering from liver disease. This bleeding is from the bursting of varices in the food pipe or the stomach. This is an emergency that needs ICU admission and urgent upper gastrointestinal endoscopy to stop continued bleeding. Placing rubber bands around the bleeding varices, injection of medicines into and around varices, or injecting glue into the gastric varices helps in controlling the bleeding. In most cases, this bleeding can be stopped by the endoscopic procedure. However, this can only be a temporary arrangement and may require repeated sessions. In refractory cases, placing a stent in the liver can help (TIPPS method). However, whenever possible liver transplantation is the only way where the liver function returns to normal thereby reducing entirely the chances of rebleed.
What is acute liver failure? What are its causes, treatment, and prognosis?
In a person who has no pre-existing history of liver disease, sometimes the liver fails to function suddenly due to various reasons. This condition is called acute liver failure. Causes of acute liver failure are:
Indiscriminate use of over-the-counter medicines such a paracetamol
Excessive use of prescription medications, especially antibiotics
Hepatitis and other viruses
Diseases of the veins in the liver
Shock – infections such as sepsis can obstruct the blood flow to the liver, causing liver failure
Treatment for acute liver failure must be initiated as soon as possible. Patients are preferably admitted to the ICU and monitored. Medications are initiated depending on the cause of acute liver failure. Antidote medicines are given if the liver disease is due to poisoning or antivirals are started in case of viral infections. Liver transplantation is an option if conservative management fails to rescue the patient. However, the timing of the liver transplantation must be appropriate.
What is fatty liver/NAFLD/NASH? What are its stages and treatment?
Nonalcoholic fatty liver disease (NAFLD) or fatty liver is a condition that arises due to excess accumulation of fat in the liver. This is a modern-day disease arising due to sedentary life and uncontrolled eating habits. Generally, in fatty liver disease, the liver functions are normal. In few situations, there is progressive damage which will lead to inflammation of the liver. This condition is called nonalcoholic steatohepatitis.
This condition can lead to cirrhosis, liver cancer, liver failure, and cardiovascular disease.
NAFLD is a disease spectrum that involves: Simple fatty liver (steatosis)
Nonalcoholic steatohepatitis (NASH)
What is alcoholic liver disease?
Excessive intake of alcohol or consumption of alcohol for a long duration will lead to irreversible damage to the liver. The extent of liver damage can manifest as alterations in liver function, enlargement of the liver, and features of liver failure. Severe alcoholic hepatitis is a dreadful condition in which the liver becomes very sick and is difficult to treat. Abstinence from alcohol is found beneficial at all stages of liver disease.
Hepatitis B – treatment and prevention
Hepatitis B is a common cause of chronic liver disease. While vertical transmission from the mother is a common mode to acquire this infection, it is also spread by unsafe blood transfusion, unprotected sex, and unsterile needle use.Hepatitis B virus infection is often diagnosed on routine health screening or during investigating a patient with liver disease. Treatment of Hepatitis B depends on the stage of the liver disease and the severity of Hepatitis B infection. There are oral Hepatitis B medications easily available that have excellent outcomes. All high-risk cases must be screened for Hepatitis B infection and be treated adequately. Vaccination against Hepatitis B prevents the infection in an individual. In cases of severe liver disease due to hepatitis B, Liver transplantation is a good option.
Hepatitis C – Treatment and prevention
Hepatitis C is a common cause of chronic liver disease. It is mostly acquired by unsafe blood transfusion, unprotected sex, and unsterile needle use. Hepatitis C infection is often diagnosed on routine health screening or during investigating a patient with liver disease. Treatment of Hepatitis depends on the stage of the liver disease and the amount of virus present in the blood. Oral Hepatitis C medications have been easily available for the last few years which have excellent outcomes. Direct-acting antiviral tablets are the safest and effective treatment for hepatitis C. They are taken for 8 – 12 weeks and clear infection in more than 90% of people. All high-risk cases must be screened for Hepatitis C infection and be treated adequately. Liver transplantation is a good option.
The spread of Hepatitis C can be achieved by practicing safe sex, not sharing personal care items
And by avoiding exposure to blood or blood products
Liver cancer – types, staging, treatment – surgery, radiology, transplant
Hepatocellular carcinoma or HCC is the most common type of primary liver cancer. It occurs in people who have liver cirrhosis caused by various reasons. It can also sometimes be seen in a non-cirrhotic healthy liver.
Cholangiocarcinoma accounts for 10-20% of liver tumors and originates from the bile duct system. It has to be differentiated from HCC since the treatment modalities are different.
Liver angiosarcoma is a rare form of cancer that begins in the blood vessels of the liver and progresses quite quickly.
Hepatoblastoma is almost exclusive to children, particularly in those below 3 years. If found in the early stages, the survival rate is more than 90%.
Treatment of liver tumors depends on the size and number of the tumor, background liver disease, situation of the tumor, invasion of the blood vessel, etc. If the liver tumor is small and diagnosed early with the remaining liver tissue being good, removal of the tumor by surgery may be sufficient. Other modalities of treatment include Hepatectomy, radio ablation therapy, embolization, and chemoembolization. Liver transplantation can be successfully performed in all eligible patients.