• Hydatid disease caused by the microscopic cestode parasites Echinococcus granulosus and Echinococcus multilocularis
• Form larval cysts in mammalian tissue
• Foxes, coyotes, dogs, and cats are the definitive hosts that harbor the adult tapeworms in their intestines
• Host animals are not harmed by the worms and are asymptomatic
• Ova are passed in the feces and are ingested by intermediate hosts such as cattle, humans, rodents, and particularly sheep
• Ova penetrate the intestine and pass via the portal vein to the liver (75%) and then to the lung (15%) or other tissues
• Ovum typically develops into a cyst filled with clear fluid
• Scoleces bud into the cyst lumen
• Cysts grow slowly; patients may be asymptomatic for several years
• Endocysts may cause secondary intraperitoneal cyst formation if spilled into the peritoneal cavity
• 80% of hydatid cysts are single and in the right lobe
• Eosinophilia is present in about 40% of patients
• Serologic tests (eg, indirect hemagglutination, complement fixation, dot immunobinding, and ELISA) are specific and sensitive, yielding positive results in 80% or more of cases of hepatic hydatid cyst
• Elevated liver function tests
• Casoni skin test
• US and CT scanning: Calcification and daughter cysts within the parent cyst
• Nuclear medicine imaging: Can also reveal uptake characteristic of hydatid cyst
• Abdominal x-ray: Can show calcific mass
• Nonparasitic cysts
• Hepatic neoplasm
• In some patients, the parasite dies, the cyst wall calcifies, and therapy is not required
• The surgical aim is to remove any cysts without disseminating the organism
• Excision of the intact cyst
• Scolicidal agent (hypertonic sodium chloride solution or sodium hypochlorite solution) can be placed into the cyst. Do not use alcohol because of fire risk.
• Care must be taken to avoid rupturing the cyst and spilling its contents into the peritoneal cavity because of the dangers of anaphylaxis or implantation
• Consider percutaneous drainage and albendazole
• Symptomatic and asymptomatic cysts, unless asymptomatic cysts completely circumferentially calcified
• Abdomen explored and cysts are isolated
• Superificial cysts may be excised
• Large cysts may be unroofed and contents removed piecemeal
• Pericystectomy is excision ...
Log In to View More
If you don't have a subscription, please view our individual subscription options below to find out how you can gain access to this content.
Want remote access to your institution's subscription?
Sign in to your MyAccess profile while you are actively authenticated on this site via your institution (you will be able to verify this by looking at the top right corner of the screen - if you see your institution's name, you are authenticated). Once logged in to your MyAccess profile, you will be able to access your institution's subscription for 90 days from any location. You must be logged in while authenticated at least once every 90 days to maintain this remote access.
If your institution subscribes to this resource, and you don't have a MyAccess profile, please contact your library's reference desk for information on how to gain access to this resource from off-campus.
AccessSurgery Full Site: One-Year Subscription
Connect to the full suite of AccessSurgery content and resources including more than 160 instructional videos, 16,000+ high-quality images, interactive board review, 20+ textbooks, and more.
Pay Per View: Timed Access to all of AccessSurgery
24 Hour Subscription $34.95
48 Hour Subscription $54.95
Pop-up div Successfully Displayed
This div only appears when the trigger link is hovered over.
Otherwise it is hidden from view.