Liver abscess

What is a liver abscess? This is the development of an inflammatory process in liver tissues to the point of their necrosis and the formation of a cavity with purulent contents. That is, an abscess is the result of inflammation, which can be caused by a number of reasons.

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Epidemiology

According to clinical statistics, an abscess of the right lobe of the liver is diagnosed five times more often than an abscess of the left lobe, and twice as many cases are diagnosed when bilateral suppuration is detected.

The epidemiology of liver abscesses gives every reason to assert that purulent liver abscesses are the most common type of visceral abscess: they account for almost 48% of cases of purulent abscesses of abdominal organs. According to some data, the annual incidence is estimated at 2.3-3.6 cases per 100 thousand population; the pathology occurs in men 2.5 times more often than in women.

The highest incidence of amoebic liver abscess in the world is found in East Asian and Asian-Pacific countries. According to WHO, 12% of the world's population is chronically infected with dysenteric amoeba and may have latent chronic liver abscess.

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Causes liver abscess

Experts name gallstones and the resulting cholecystitis or cholangitis as the most common cause of liver abscess. Liver abscess may also be a consequence of a ruptured inflamed appendix, perforation of a stomach ulcer or sigmoid colon in diverticulosis; ulcerative colitis; pyogenic inflammation of the portal vein; Crohn's disease; general blood poisoning; cholangiocarcinoma; colorectal cancer or malignant tumor of the pancreas; suppuration of liver cysts or organ injuries.

Pyogenic or purulent liver abscess (code K75.0 according to ICD-10) always has an infectious etiology. And the pathogenesis is associated with the entry of microbes into the liver (mainly E. coli, St. milleri, St. pyogenes, St. faecalis, Pseudomonas Spp., Clostridium welchii, Proteus vulgaris, Klebsiella pneumoniae, Bacteroides Spp.), migrating from the primary inflammation site with the blood flow in the form of a septic embolus.

In the liver, bacterial reproduction continues, which leads to the death of parenchyma cells and necrosis of its individual sections with the formation of an infiltrate; then the infiltrate melts and a cavity filled with pus is formed, surrounded by a fibrous capsule. Often, partitions form in the capsules. This is how bacterial liver abscesses develop.

When the same bacteria penetrate the liver from the gallbladder (the primary site of infectious inflammation) through the extrahepatic bile ducts, doctors determine biliary or cholangiogenic liver abscesses. Among their causes, in addition to obstruction of the bile ducts due to the presence of stones in them, there are narrowings of the lumen (stenosis and strictures) of the ducts of iatrogenic origin: after bile-hepatic surgical interventions, as well as the use of drugs (for example, steroids or cytostatics).

In addition, the causes of liver abscess may be associated with parasite invasion (ascarids, echinococci or dysenteric amoeba). In particular, when the liver is affected by dysenteric amoeba (Entamaeba histolytica), an amoebic liver abscess (ICD-10 code - A06.4) or extraintestinal dysenteric amebiasis of the liver develops. Infection occurs by the feco-oral route in endemic regions (tropics and subtropics). Amoebas invade the intestinal mucosa and can gain access to the portal vein system and then penetrate the liver tissue, where they are transformed into trophoisomes and clog the liver capillaries. As a result of necrosis of hepatocytes deprived of nutrition, a chronic liver abscess is formed.

It has been established that amoebic liver abscess can occur without a previous history of amoebic colitis and dysentery, that is, the infection can manifest itself months and even years after amoebic invasion.

Much less frequently diagnosed is a liver abscess of fungal etiology (Candida, Aspergillus), which develops after chemotherapy for malignant neoplasms in the abdominal organs or leukemia - in patients with a severely weakened immune system.

The focus of purulent inflammation of the liver parenchyma is often solitary (single), but in some pathologies - in the case of the formation of stones in the liver, with a cholangiogenic origin of the focus of infection, with extraintestinal amebiasis - multiple liver abscesses may occur.

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Risk factors

Risk factors for the development of liver abscesses include diabetes mellitus, liver cirrhosis, severe pancreatic disease, liver transplantation, cancer, immunodeficiency, and age over 70 years.

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Symptoms liver abscess

The clinical symptoms of liver abscess are non-specific and similar to other hepatobiliary inflammatory processes and infections. As a rule, the first signs of a purulent liver abscess include pyrexia (fever above +38.5°C with chills and profuse sweating at night), lethargy and general malaise, discomfort and periodic pain in the right upper quadrant of the abdomen (the pain becomes stronger with pressure), an ashy complexion. Nausea and vomiting, complete loss of appetite and body weight, a significant increase in the size of the liver (often with protrusion into the right hypochondrium) are also observed.

Less common symptoms include cough, shortness of breath, or hiccups, which occur due to irritation of the diaphragm by the damaged liver; pain radiating to the right shoulder and back; yellow tint of the skin and sclera (when cholangiogenic liver abscesses develop).

An amoebic liver abscess can have practically the same symptoms, but it happens that the only complaint is either an increase in temperature (up to +38°C) or pain in the right side of the abdomen.

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Complications and consequences

If appropriate medical measures are not taken in time, the consequences of a purulent liver abscess will inevitably lead to death as a result of subsequent complications.

The complications of this pathology are numerous and very dangerous. First of all, it is a rupture of the abscess cavity with the outpouring of necrotic masses into the pleural or peritoneal cavity. The result is pleural empyema or peritonitis with the risk of sepsis. The breakthrough of pus and its accumulation in the depression located under the dome of the diaphragm leads to the so-called subdiaphragmatic abscess. And the ingress of serous-purulent contents of the perforated abscess of the left lobe of the liver into the pericardial sac can cause inflammation of the outer membrane of the heart (pericarditis), as well as exudative pericarditis and pericardial tamponade.

In addition, complications of liver abscesses include increased pressure in the hepatic portal vein system (which can result in bleeding); fluid accumulation in the abdominal cavity (ascites); septic embolism of the pulmonary arteries; and abscess of brain tissue.

An amebic liver abscess can also break through the diaphragm into the pleural cavity and lungs, which often leads to the appearance of fistulas.

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Diagnostics liver abscess

Diagnosis of liver abscess begins with anamnesis and palpation of abdominal organs. Laboratory tests are required, for which the following tests are taken: general and biochemical blood tests (including bilirubin and alkaline phosphatase), blood culture, urine analysis.

If extraintestinal amebiasis is suspected (if it turns out that the patient has been in endemic regions), it is necessary to examine feces for cysts or trophozoites of the dysenteric amoeba, as well as the behavior of serological tests. And to determine the type of bacteria, percutaneous puncture aspiration of purulent exudate is performed.

Today, instrumental diagnostics expands the capabilities of medicine, and in addition to conventional abdominal X-rays, cholangiography (X-ray of the bile ducts with a contrast agent) and splenoportography (X-ray of the liver vessels), ultrasound and CT are used.

The main ultrasound signs of a liver abscess are the presence of hypoechoic structures of varying volumes with a low attenuation coefficient of the ultrasound signal in the organ tissues.

Contrast during examination allows to more accurately determine the nature of the formations, establish their size and the presence of internal partitions. This is important, since for small abscesses (up to 3 cm) with partitions inside the purulent cavity, drainage is not recommended.

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Differential diagnosis

The differential diagnosis of liver abscesses is very difficult. Firstly, it is difficult to clearly differentiate amoebic liver abscesses from pyogenic ones. And purulent abscesses should be distinguished from liver cysts, pleurisy with purulent capsules, subdiaphragmatic abscess, cholecystitis, hepatocellular carcinoma or liver metastases.

Treatment liver abscess

Doctors warn that in case of liver abscesses neither homeopathy, nor folk remedies, nor attempts to use herbal treatment are allowed.

Currently, the standard treatment for liver abscesses is minimally invasive methods in combination with targeted antimicrobial therapy.

To remove purulent contents from the cavity, ultrasound- or CT-controlled puncture drainage of the liver abscess is performed. Drainage catheters are placed through the skin in all patients either immediately after the initial aspiration during diagnostics or within 24 hours of exacerbation. The duration of placement of catheters through which pus comes out can vary from three days to a week, which depends on the results of repeated visualization of the abscess and the clinical condition of the patients. Pathogens of inflammation are cultured from the aspirated contents of the abscess. During catheter placement, there is a risk of spreading pus from the abscess with subsequent bacteremia and sepsis.

At the same time, the following medications are prescribed: antibiotics Amoxiclav (Amoxil, Augmentin), Clindamycin (Klimitsin, Cleocin, Dalacin C), Ceftriaxone, etc. The drugs are administered intravenously: Amoxiclav - 1000 mg every 8 hours; Clindamycin - 250-300 mg up to 4 times a day; Ceftriaxone - 50 mg per kilogram of body weight. Side effects of these antibiotics may include nausea and diarrhea, urticaria, increased activity of liver transaminases and alkaline phosphatase levels (especially in elderly patients).

Antiprotozoal drugs used to treat amoebic liver abscess include Metronidazole, Tinidazole, and Diloxanide. Metronidazole acts directly on the trophozoites of E. histolytica. Even a single oral dose of this drug (2.5 g) and simultaneous puncture drainage of the liver abscess gives a positive effect. Metronidazole is most often used parenterally - in the form of prolonged infusions of 0.5-1 g 4 times a day. Side effects include gastrointestinal symptoms, headaches, tongue coating, dry mouth and metallic taste in the mouth; sometimes dizziness, ataxia and paresthesia, urination disorders, and allergic reactions are observed.

Treatment of liver abscess of fungal etiology is carried out with the antifungal antibiotic Amphotericin B (administered intravenously by drip, the dosage is calculated based on body weight).

Surgical treatment of liver abscess is necessary when conservative therapy is ineffective. And, as a rule, surgery is needed when the abscess is complicated. The intervention can be performed openly or laparoscopically and may include either open drainage of the abscess cavity or resection (excision) of the inflammation focus and affected tissues.

A diet for liver abscess helps to ease the course of the disease; in particular, diet No. 5 according to Pevzner is very suitable.

Prevention

Considering the etiology and pathogenesis of liver abscesses, their prevention consists of timely treatment of hepatobiliary and gastrointestinal diseases, as well as compliance with hygiene rules.

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Forecast

According to WHO, the prognosis for the outcome of liver abscess has improved significantly over the past 30 years. If in the middle of the last century the mortality rate of patients who developed purulent liver abscess was 60-80%, today - subject to timely identification of the disease and adequate medical care - the mortality rate ranges from 5 to 30%.

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