Liver Abscess

Question 1

What are liver abscesses?

Answer 1

Liver abscesses typically result from a polymicrobial bacterial infection spreading from the biliary or gastrointestinal tract, either via contiguous spread or seeding from the portal and hepatic veins.

Question 2

What are the common causes of liver abscesses?

Answer 2

Common causes include cholecystitis, cholangitis, diverticulitis, appendicitis or septicaemia.

Question 3

What are the most common organisms causing liver abscesses?

Answer 3

The most commonly isolated organisms are E. Coli, K. pneumoniae, and S. constellatus, although fungal causes may also be present in immunocompromised patients.

Question 4

What are the clinical features of a liver abscess?

Answer 4

Patients typically present with fever, rigors, and abdominal pain. Other symptoms include bloating, nausea, anorexia, weight loss, fatigue and jaundice.

On examination, patients will have RUQ tenderness +/- hepatomegaly. If the abscess ruptures (a rare complication), then patients may present with signs of shock.

Question 5

What investigations should be ordered for a liver abscess?

Answer 5

FBC will show a leucocytosis and LFTs are often abnormal, with a raised ALP in most cases and deranged ALT and bilirubin in a proportion. All patients should also have peripheral blood and fluid cultures sent for microscopy.

Ultrasound imaging will reveal poor-defined lesions with hypo- and hyper-echoic areas, with potential gas bubbles and septations.

Further delineation can be achieved by CT imaging with contrast, revealing a similar pattern from the collection as seen on US with associated surrounding oedema.

Question 6

How will liver abscesses appear on imaging?

Answer 6

Lesions with hypo- and hyper-echoic areas, with potential gas bubbles and septations.

Question 7

Briefly describe what is shown on the CT scan

Answer 7

CT scan showing a liver abscess, seen as a hypodense lesion with peripheral enhancement

Question 8

Briefly describe the management of a liver abscess

Answer 8

Patients should be fluid resuscitated and stabilised accordingly, and started on appropriate antibiotic therapy (guided by sensitivities and local policies)

Most cases can be drained via image-guided aspiration of the abscess (with or without catheter drainage), either US or CT, for source control. Any underlying cause should also be addressed once the patient has been appropriately managed

Surgery is rarely indicated, predominantly if the abscess has ruptured or refractory to antibiotic treatment.