Liver Abscess

Introduction

Liver abscesses are common in children in India. Liver abscesses are space occupying infectious lesions in the liver.¹ The two very common abscesses are pyogenic and amoebic while fungal abscesses are rare.^1,2 Pyogenic abscess constitute 80% of liver abscesses in children.

Incidence

The incidence of pyogenic liver abscess (PLA) in children in India is reported around 79 per 1,00,000 admissions. Amoebic liver abscess (ALA) is rare and found in less than 1% of children infected with Entamoeba histolytica.¹

Pathophysiology

Liver has a dual blood supply which predisposes it to an increased risk of infection. Pyogenic liver abscess is a suppurative infection of liver parenchyma. The common organisms involved in PLA are staphylococcus, Klebsiella pneumonia, Enterobacter, Escherichia coli.^1,2 Entamoeba histolytica causes apoptosis and necrosis of hepatocytes. There are no inflammatory cells due to neutrophilic lysis and typically forms non purulent anchovy sauce abscess.² Various predisposing factors for PLA include chronic cholangitis, systemic bacteremia, intestinal infections, umbilical vein catheterization in neonates, chronic malnutrition, etc. Around two third of liver abscesses occur in right lobe of liver which can be attributed to high right portal vein flow and right portal vein continues in direction of common portal vein.¹

Clinical presentation

The mean age at presentation is about 8-10 years age.³ Most common presentations include fever, abdominal pain, vomiting, loss of appetite, jaundice. Hepatomegaly with right upper quadrant tenderness is common.^1,4

Investigations

Ultrasonography of abdomen is the initial investigation of choice for the assessment of liver abscess and its features like size, site and number, etc. Contrast-enhanced computed tomography (CT) and magnetic resonance imaging are sensitive to detect small size abscesses.¹ ALA commonly occurs as a single lesion in right lobe of liver, but can be multiple. PLA are usually multiple.¹ Blood cultures are important tool in PLA while antigen testing for detection of E histolytica may be useful in ALA.²

Treatment

Broad spectrum antibiotics which cover gram positive, gram negative, and anaerobic organisms are initial treatment for PLA. Two week intravenous antibiotics followed by 4 weeks oral antibiotics is recommended.¹ Metronidazole or tinidazole for 5-10 days are mainstay treatment for ALA. This is followed by luminal agent like paromomycin for 5-10 days. Liver abscesses of less than 3 cm can be treated well by medical management.² Perctaneous needle aspiration along with antibiotics are recommended for unilocular liver abscess. Percutaneous drainage (PD) procedure has now become mainstay in the management of liver abscess. PD is indicated in large volume abscess and in risk of spontaneous rupture. Surgical management with open laparotomy is indicated when there is no response to PD with antibiotics, when pus is thick, abscess is multiloculated, or rupture into peritoneal cavity.¹

Complications

Untreated liver abscess can develop complications such as empyema, sepsis, rupture of liver abscess in peritoneal or pleural cavity. Rare complications include vascular complications like hepatic venous outflow tract obstruction and portal vein thrombosis which may occur due to mass effect or rupture of abscess.⁵