Liver abscess
Summary/Definition
Liver abscess is a process in which bacteria or parasites multiply in the liver, followed by the accumulation of pus in the organ and the development of the disease. When an abscess forms outside the body, for example, on the skin or in the muscles, it can be cured by opening, drainage, disinfection and the use of antibiotics. However, an abscess forming inside the body, such as in the liver, cannot be visually detected. In the case of an abscess formed on the skin, its presence can be determined by characteristic signs, for example, redness and swelling of the skin. However, an abscess developing inside internal organs such as the liver can cause symptoms similar to those of a cold, such as fever and general weakness, as well as signs of inflammation. Sometimes it can manifest itself with symptoms resembling gastritis, for example, pain in the upper abdomen, which complicates the diagnostic process. Since the symptoms of Liver abscess are nonspecific, it is a serious disease that, with late diagnosis and untimely treatment, can lead to sepsis and peritonitis, posing a threat to life. Therefore, timely diagnosis and treatment are crucial. However, if antibiotics are used in parallel with drainage and the disease is detected at an early stage, the prognosis of effective treatment is very favorable.
Reasons
Depending on the etiology of the liver abscess, it is classified as a purulent abscess and a parasitic (amoebic) liver abscess.
Purulent Liver abscesses are caused by the multiplication of bacteria, and about 80% of cases of purulent abscesses are caused by the bacterium Klebsiella pneumonia. Parasitic (amoebic) Liver abscess associated with an amoeba (Entamoeba histolytica). In the past, this type of abscess was common in the Republic of Korea due to unfavorable sanitary conditions. However, since the 1990s, there have been practically no cases of its outbreaks in the country.
- The general mechanisms of Liver abscess development are divided into the following categories:
- Cases where the mechanism of infection is unknown (50% of cases).
- Causes related to the biliary system (40% of cases).
- Hematogenic transmission (10% of cases).
Many cases of Liver abscess are associated with the biliary tract. Diseases that may develop in these cases include intrahepatic or extrahepatic gallstone disease, including hepatic fluke and cholecystitis. In some cases, a Liver abscess may be caused by an intrahepatic malignant tumor. Therefore, a detailed examination is required to detect the presence of a possible malignant tumor in the liver.
Symptoms
Purulent Liver abscess is accompanied by the appearance of various clinical signs and symptoms due to the presence of pus in the liver caused by bacteria or parasites, and the development of the inflammatory process.
- Temperature rise (90%)
- Abdominal pain and soreness (55-74%)
- Chills (38-49%)
- Decreased appetite (38%)
- Weight loss (25-43%)
- Nausea and vomiting (28-43%)
- Weakness and fatigue (30%)
There may be pain when pressing on the upper abdomen, as well as an increase in the liver or the appearance of jaundice of the skin (a pigment called bilirubin settles in the skin, giving the face or body a yellow hue). These symptoms usually appear within two weeks, but in rare cases they may occur after 5-6 months.
The signs and symptoms of amoebic Liver abscess are almost identical to those observed with purulent liver abscess. However, they are more often less pronounced than with purulent abscess, and include fever, chills, general malaise, nausea, vomiting, loss of appetite and weight loss. Some patients may have complaints of chest pain, cough, or difficulty breathing. Diarrhea is rare, in about 20% of cases. The liver may be enlarged, and patients may feel pain on palpation in the upper right quadrant of the abdomen. Jaundice occurs somewhat less frequently than with purulent liver abscess, in about 5-8% of cases.
Diagnostics
When contacting a medical institution with symptoms similar to a liver abscess, the doctor conducts a detailed consultation and examination of the patient to assess the symptoms, after which he performs the necessary diagnostic procedures, for example, blood tests, liver ultrasound (ultrasound) and computed tomography (CT) of the abdominal cavity.
1. Consultation
The analysis of general information is carried out, including the time of occurrence and severity of symptoms, anamnesis of the disease (for example, the presence of hepatitis, cholelithiasis, cancer, diabetes mellitus and others), assessment of the general condition of the patient, taking into account information about his place of residence and data on movement.
2. Medical examination
Due to the fact that the liver is located in the upper right part of the abdomen, patients sometimes report unpleasant sensations in this area. However, in some cases, abdominal pain may be absent. If, during palpation of the patient, the doctor detects painful sensations (pressure pain) in the upper right part of the abdomen, this may be the key to making a diagnosis.
3. Blood test
In patients with liver abscess, blood tests are performed, including tests for markers of inflammation, liver function indicators, as well as tests for diseases associated with Liver abscess(for example, hepatitis, liver cancer, biliary tract abnormalities, etc.). However, the abnormalities detected in blood tests are not specific in the diagnosis of an abscess liver. Among the most common abnormalities, there is an increase in the number of leukocytes (more than 80%) and an increase in the level of alkaline phosphatase in the blood serum (more than 60%), and other changes may occur, including hypoalbuminemia, an increase in the level of liver enzymes (ALT / AST) and an increase in bilirubin.
4. Bacteriological analysis
The pathogens of purulent Liver abscesses are diverse and, sometimes, reflect the path of infection. Bacteria can be divided into aerobic, which multiply in the presence of oxygen, and anaerobic, which multiply in the absence of oxygen. In the case of purulent liver abscesses, mixing of facultative aerobes and anaerobes is often observed. The presence of bacteria in the removed pus is confirmed if the proportion of bacteria in the liquid is 41.4-51%, while the proportion of positive results of a bacteriological blood test varies from 13.5% to 59.5%. When staining bacteria for microscopic examination, aerobic bacteria are divided into gram-positive and gram-negative, and gram-negative strains are most often found in purulent liver abscesses (they account for more than 70%). The most common cause of purulent liver abscess, according to available data, is Klebsiella pneumonia.
With amoebic liver abscess, the same diagnostic method is used as with purulent liver abscess. Additionally, a hematological examination is carried out in order to identify parasites. The probability of detecting amoebas in the feces is only 15%, while when conducting a study of indirect hemagglutination, the probability of diagnosis increases to more than 95%. However, negative results are often noted in the first week of the disease, and it takes 24-48 hours to obtain final data. Therefore, it is recommended to start empirical treatment and wait for the results.
5. Visualization studies
Ultrasound of the abdominal cavity and computed tomography (CT) of the abdominal cavity are an integral part of the process of diagnosing liver abscess. If necessary, additional methods can be applied, for example, cholangiography and endoscopic examination. Visual examination is necessary to differentiate between a Liver abscess and a liver cyst or liver cancer. In case of doubt, additional studies may be required, for example, hematological tests, bacteriological studies, drainage procedures, biopsy, and determination of cancer markers. Visual examinations allow us to determine the size, location, shape, and number of foci of liver abscess, to identify the presence or absence of air bubbles, as well as to determine the possibility of drainage and the presence of concomitant diseases (for example, liver cancer or biliary tract abnormalities). These data provide important information for accurate diagnosis, treatment planning, and prognosis of the disease.
6. The results of the pathoanatomic examination
Liver abscess can have different sizes (from several millimeters to several centimeters) and manifest as a single lesion or as multiple foci. If the abscess spreads through the portal vein of the liver, hepatic artery or bile duct, then multiple small abscesses occur more often. In the case when the abscess penetrates directly into the liver parenchyma, one large abscess is formed. Histopathological characteristics are similar to purulent abscesses that occur in other anatomical areas, with the replacement of the liver parenchyma with purulent exudate and the presence of acute or chronic inflammatory cells that penetrate into the surrounding tissues. Over time, the granulation tissue formed around the abscess turns into a capsule.
Treatment and course of the disease
For effective treatment of purulent liver abscesses, it is usually necessary to use a combined approach, including antibiotic therapy and drainage procedures. At the same time, it is necessary to evaluate the possibility of drainage using visualization methods and take into account the presence of concomitant diseases, for example, liver cancer, gallstone disease or biliary tract abnormalities, and provide appropriate treatment for these diseases. The approach to the treatment of liver abscesses is individual and depends on the number of foci and the cause of their occurrence. Therapy methods vary and may include antibiotic therapy, percutaneous drainage, surgical drainage, or liver resection.
- Cases when the prognosis is unfavorable during treatment:
- Old age (over 70 years old)
- Multiple liver abscess
- Cases of Liver abscess against the background of biliary tract disease
- Cases when a Liver abscess accompanied by a malignant tumor
- Low serum albumin level
- The size of the abscess focus is more than 10 cm ? The presence of air bubbles inside the abscess.
Medical treatment
1. Antibiotic treatment
Patients who have previously received treatment without drainage usually receive antibiotics for a longer period. With prolonged use of antibiotics, problems associated with resistance to them may develop. Also, with the empirical use of antibiotics without a confirmed bacterial infection, there is a risk of sepsis and complications associated with antibiotic abuse. Therefore, combined treatment with the use of antibiotics and drainage is considered the most effective method. The duration of antibiotic treatment for purulent Liver abscess usually at least 4-6 weeks. Injections of antibiotics are carried out during the first 2-3 weeks or until the necessary clinical response is achieved, after which they switch to oral antibiotics. In the case of a parasitic liver abscess, metronidazole is used for 7-10 days. This method of treatment usually provides effectiveness over 90%.
Non-drug treatment
1. Drainage as a treatment method
Percutaneous drainage is the most common drainage method. This procedure involves removing the abscess from the tissues by inserting a needle or drainage tube through the skin. Percutaneous drainage includes the method of aspiration with a thin needle and the method of installing a drainage tube. If the diameter of the focus of the Liver abscess does not exceed 5 cm, aspiration using a thin needle is the preferred method. If the diameter of the abscess lesion exceeds 5 cm, it is recommended to insert a drainage tube. After the introduction of the drainage tube, it is left in place until the volume of the drained liquid decreases, and then its removal is carried out. Usually, the volume of fluid released is significantly reduced within a week after the installation of drainage. The advantage of drainage is that there is no need for general anesthesia and surgical opening of the abdominal cavity, which makes the procedure simple and adaptable to patients. However, it is necessary to be careful when draining patients with ascites, disorders of the blood clotting system or abscesses located close to large vessels. In the presence of ascites, there is a risk of ascites leaking through the drainage tube and the spread of infection in the abdominal cavity through ascites. In case of blood clotting disorders, the installation of a drainage tube can be dangerous due to the risk of bleeding. If the abscess is located near critical blood vessels, there is a possibility of damage to them, which is life-threatening.
This type of drainage may not be suitable for all cases of liver abscesses. Factors that can complicate percutaneous drainage include multiple, large abscesses, abscesses of the endoplasmic reticulum that can clog the drainage tube, as well as cases accompanied by diseases that primarily require surgical treatment (for example, diseases of the biliary tract).
Parasitic (amoebic) Liver abscesses are treated with anti-amoebic drugs, and in 90% of cases it is successful. Percutaneous drainage is performed in the absence of a response to antiamoebic treatment for 3-5 days, with complication of the Liver abscess by bacterial infection or with a high risk of rupture of the left lobe of the liver.
2. Surgical treatment
- Surgical drainage is considered in the following cases:
- When percutaneous drainage is technically difficult.
- In the presence of a biliary tract disease requiring surgical intervention.
- When the abscess ruptures and causes multiple peritonitis.
- When there is a connection between the intestinal tract and liver abscess.
- In cases of unsuccessful percutaneous drainage.
- In the absence of a clinical reaction to percutaneous drainage for 4-7 days.
- In the presence of multiple liver abscesses.
Surgical drainage is also performed in case of back problems and in case of urgent need. In rare cases, liver resection may be required.
Complications
In the case of purulent liver abscess, the development of antibiotics has significantly reduced the incidence of complications and the mortality rate, but the mortality rate still remains in the range of 6% to 32%. Complications associated with Liver abscess can cause sepsis and subsequent organ failure, which can lead to death.
- Complications of purulent Liver abscess may include:
- Respiratory complications (in 30% of cases), including pleural effusion.
- Acute renal failure.
- Peritonitis.
- Rupture of the abscess.
- Infection of the wound.
- Liver failure.
- Sepsis.
- Relapse and others.
More than 90% of cases of amoebic Liver abscess can be successfully treated with antibiotics, and the level of complications and mortality in this disease is lower than in purulent liver abscess.
