What is the most common source of liver (hepatic) abscesses?

From the Guidelines

The most common source of liver (hepatic) abscesses is portal venous seeding of diverticulitis and appendicitis, as well as obstruction of the biliary system, including the gallbladder. Specifically, pyogenic abscesses most often result from these sources, as stated in the study published in the Journal of the American College of Radiology in 2020 1. Other common sources include:

• Portal vein seeding from intra-abdominal infections (e.g., diverticulitis, appendicitis)
• Obstruction of the biliary system, including the gallbladder
• Hematogenous spread from systemic infections is not mentioned in the provided study, but it is a known source in general medicine knowledge To diagnose and manage hepatic abscesses:
• Perform imaging studies (CT or ultrasound) to confirm the diagnosis
• Obtain blood cultures and abscess fluid cultures if possible
• Start broad-spectrum antibiotics
• Consider percutaneous drainage for abscesses >4 to 5 cm in diameter, as PCD appears to be more effective than needle aspiration 1 Understanding the source is crucial for proper management and prevention of recurrence, and addressing the underlying cause is essential for long-term success. The provided study 1 highlights the importance of proper management, as morbidity and mortality from pyogenic abscess may be increased in certain patient populations.

From the Research

Etiology of Liver Abscesses

The most common source of liver (hepatic) abscesses is:

• Biliary tract disease, including lithiasic biliary disease (cholecystitis, cholangitis) 2, 3, 4, 5
• Infection can also occur via the bile ducts or vessels (arterial or portal) or directly, by contiguity 2
• Other causes include intra-abdominal collections (appendicitis, sigmoid diverticulitis, Crohn's disease), and bile duct ischemia secondary to pancreatoduodenectomy, liver transplantation, interventional techniques (radio-frequency ablation, intra-arterial chemo-embolization), and/or liver trauma 2

Bacterial Causes

• The most common bacterial causes of liver abscesses are:
  • Klebsiella pneumoniae 2, 5, 6
  • Escherichia coli 2, 5, 6
  • Streptococci 5
• Polymicrobial infections can also occur, with 16% of cultures being polymicrobial 5

Geographic Variation

• In the Western world, bacterial (pyogenic) liver abscesses are most prevalent 2
• In South-East Asia and Africa, amebic infection is the most frequent cause of liver abscesses 2