Hydatid Liver Disease

Hydatid liver disease is hepatic cystic echinococcosis caused predominantly by Echinococcus granulosus.

The liver is the commonest organ involved.

Management is stage and size specific. A hydatid cyst should not automatically undergo surgery, and unplanned aspiration is dangerous because cyst fluid can cause anaphylaxis and secondary peritoneal dissemination.

Ultrasound staging separates active, transitional and inactive disease and directly determines treatment.

Most uncomplicated cysts grow slowly and may remain asymptomatic for years.

Symptoms include right upper quadrant discomfort, hepatomegaly, nausea or a palpable mass.

Complications include:

• Intrabiliary rupture causing jaundice or cholangitis
• Secondary infection
• Intraperitoneal rupture
• Anaphylaxis
• Compression of portal or hepatic venous structures
• Thoracic extension from superior liver cysts

Sudden pain with allergic symptoms should raise concern for cyst rupture.

Ultrasound: investigation of choice and should assign a cystic echinococcosis stage.

CT or MRI is useful for complex anatomy, calcification, biliary communication or surgical planning.

Serology supports the diagnosis but negative serology does not reliably exclude hepatic hydatid disease.

Do not perform routine diagnostic aspiration of a possible hydatid cyst.

Treatment is determined by cyst stage, size, complications and biliary communication.

Albendazole

For uncomplicated active CE1 or CE3a cysts below 5 cm, use:

Albendazole 10 to 15 mg/kg/day orally in two divided doses, maximum 400 mg twice daily, with a fat rich meal.

Treatment is continuous, generally for 3 to 6 months. Monitor full blood count and liver enzymes.

For CE2 or CE3b cysts 5 cm or smaller, an initial albendazole strategy can also be used with close imaging follow up. Failure to show meaningful response after approximately 3 months should prompt reassessment for intervention.

PAIR

For uncomplicated CE1 or CE3a cysts approximately 5 to 10 cm, perform PAIR:

Puncture, aspiration, injection of a protoscolicidal solution and reaspiration, combined with albendazole.

For larger CE1 or CE3a cysts above 10 cm, percutaneous treatment combined with albendazole remains an important option in experienced centres.

Do not perform PAIR when there is biliary communication. Injection of a sclerosant or protoscolicide into a cyst communicating with the bile ducts can cause severe chemical cholangitis.

A typical peri procedural albendazole strategy is treatment for 1 to 7 days before PAIR and 1 to 3 months afterwards.

Surgery

For CE2 or CE3b cysts above 5 cm, surgery combined with albendazole is generally preferred because daughter cyst burden makes simple PAIR less effective.

Operate for complicated disease such as:

• Intrabiliary rupture
• Secondary infection
• Free rupture
• Major compression
• Cyst at high risk of traumatic rupture
• Complex daughter cyst anatomy unsuitable for safe percutaneous treatment

Aim for controlled evacuation or pericystectomy while preventing spillage.

Protect the operative field carefully and deal directly with any cystobiliary communication.

Inactive uncomplicated CE4 or CE5 cysts are generally observed rather than treated invasively.

Follow treated cysts with imaging at approximately 3 to 6 months and then annually for at least 5 years after inactivation because recurrence can occur.