What is Hydatid Cyst?

It is a parasitic hydatid disease caused by Echinococcus granulosus. It is a parasitic disease in which larval forms living in the small intestines of carnivores such as dogs, cats, foxes and wolves cause cyst formation in internal organs. The disease can affect all organs in the body, but most commonly the liver, lung and spleen.

The prevalence of hydatid cysts in our country has been reported in different studies with different rates such as 2/1000000-1/2000. Since it can be asymptomatic, only 10-20% of patients younger than 16 years of age are diagnosed. Although the cyst is most commonly seen in the liver, pulmonary localization is also common in children.

What is the evolution (life cycle) of the parasite?

The eggs of the parasite, which adhere to animals such as dogs, cats, foxes, wolves, etc., which we call the last host, are scattered around. These eggs remain alive for 7 days in water, 4 days in ice and 10 months in soil. Then, as a result of animals such as sheep, goats, etc., which we call intermediate hosts, eating foods (grass, water, etc.) contaminated with parasite eggs, the eggs pass into the intestines, open and mix into the bloodstream, causing cyst formation in the internal organs.

Later, when the organs containing cysts are eaten by carnivores, the parasite reaches the intestines of these animals again and becomes an adult. Humans may occasionally serve as intermediate hosts. If fruits and vegetables contaminated with parasite eggs are ingested, the eggs hatch in the intestine and the parasite's life cycle continues in the same way. Uncontrolled movement of animals between regions or countries also plays an important role in spreading infestation.

Is hydatid cyst transmitted through the respiratory tract (breathing)?

Since the shell of the parasite eggs ingested through the respiratory tract is dissolved by intra-tissue enzymes, there is no transmission in this way.

Figure: Life Cycle of Hydatid Cyst

Who is at Risk for Hydatid Cyst of the Liver?

A person's occupation, hobbies, living conditions, education and socioeconomic level affect the risk of developing the disease. People who have contact with infected dogs that have been released into free circulation without parasite control and people who are engaged in animal husbandry such as sheep, goats and cows constitute the biggest risk group. In recent years, it has also become common in people who keep unvaccinated cats and dogs at home but are not engaged in animal husbandry.

Hydatid cyst most commonly affects the liver (75-80%). The reason for this is that the parasite, which passes from the intestine into the bloodstream, necessarily visits the liver first. The fact that the liver cell structure is like a filter ensures that the parasite stays there without passing to other organs. Those that can pass through this filter get stuck in the lung, which is a finer filter. Hydatid cysts settle in the lung most frequently (20-30%), while other organs (spleen, kidney, brain, bone) settle around 10%. 5-30% settle in the liver and lung together.

What are the Clinical Symptoms of Hydatid Liver Cyst in Children?

The cyst is a pathology that grows and matures slowly and over years. Since the cysts are very well encapsulated, the disease may not show systemic symptoms such as fever, fatigue and weight loss in the early stages. Therefore, whether the cyst is in the liver or in another organ, patients appear to be quite healthy. Although the patient may remain asymptomatic for a while, some complaints may occur depending on the organ in which the cyst is located due to rupture or infestation of the cyst. These complaints usually include abdominal pain, nausea, vomiting, jaundice, respiratory distress, cough, headache and impaired hearing, vision, perception and coordination. To list these symptoms

• Severe abdominal pain
• Bloating and indigestion
• Nausea and vomiting
• Jaundice (due to obstruction in the gallbladder or rupture of the cyst)
• High fever
• Acute abdominal clinic (due to rupture of the cyst)
• Allergic findings: If the cyst ruptures, fever, urticaria, eosinophilia, hypotension and even anaphylaxis may develop.

How is Liver Hydatid Cyst Diagnosed?

The main approach to diagnosis is history and physical examination. Therefore, the patient should be well rested and a complete systemic examination should be performed. Apart from this, some blood tests and imaging methods are utilized.

1. Blood tests; In addition to routine liver enzymes, blood count, bleeding and coagulation tests, some tests specific to Hydatid Cyst can be performed.

   1. Immune Fluorescent Antibody (IFA) Test; It is a test with high sensitivity. In studies, its sensitivity is reported as 52-93% and specificity as 90%. The sensitivity of this test in lung cysts is 80%.

   2. Western Blot Test; This test provides a more definitive diagnosis. This test is also a more sensitive method in determining the prognosis of the disease.

   3. Casoni Skin Test; The sensitivity of the test is low (55-65%), so it has been abandoned today. In addition, this test sensitizes the person and may cause false positivity in subsequent serologic tests.

   4. Indirect Hemagglutination (IHA) Test; In studies, the sensitivity and specificity of this test are reported as 80-94% and 90-95%, respectively. However, these rates are reported as 80% in Lung Cysts.

   5. Enzyme-Linked Immunosorbent Assay (ELISA) Test; Its sensitivity is lower than other tests (72-76%) and specificity is 89-100%.

2. Imaging Methods; Direct X-ray, Ultrasonography and Computed Tomography are performed. The last two imaging studies are also important in the follow-up of the disease.

Liver Hydatid Cysts are classified ultrasonographically as determined by the World Health Organization and an author named Gharbi. These classifications show the condition of the disease and also guide the treatment.

What is the Ultrasound Classification (Gharbi Classification) of Hydatid Cyst of the Liver?

• Type I : Cyst purely cystic (spherical, oval and thick-walled)
• Type II : Cyst purely cystic and germinative membrane separated from the cyst
• Type III: Cyst septated and contains numerous daughter vesicles
• Type IV : The structure of the cyst is heterogeneous (contains hyper- and hypoechoic areas)
• Type V : The cyst and its wall are completely calcified.

Is Garbi Classification Important in Treatment?

Yes, it does. According to the Garbi classification, the treatment plan is as follows:

Type I : PAIR or surgery because the cyst is purely cystic

Type II : Cyst purely cystic and germinative membrane separated from the cyst, PAIR or surgery.

Type III : Surgery (Open or Laparoscopic)

Type IV : surgery (open or laparoscopic)

Type V: Calcification indicates that the cyst is dead, therefore no procedure is performed, it is followed up.

Image: Computed Tomography Images of Liver Hydatid Cyst Disease

What are the Conditions Causing False Positive Hydatid Cyst Tests?

• Other Parasitic Diseases; Taneia, Ascaris, Enterobius.
• Cancer; Lymphoma, Leukemia, Lung Cancer
• Chronic Diseases; TB (Tuberculosis), Connective Tissue Diseases etc.
• Non-Liver Localization of Hydatid Cyst; Lung, Spleen, Brain...
• Calcified Dead Cysts

How is hydatid liver cyst treated in children?

There is no fixed treatment for Hydatid Cyst of the Liver, there are different treatment options. The patient's age, social status, the size of the cyst, the organs involved and the radiological appearance of the cyst are taken into consideration in determining the treatment option of Hydatid Cyst. For example, PAIR for Gharbi type 1 and 2 types used in the classification of hydatid cysts,

The treatment option should be decided together with the pediatric surgeon, parents and the patient in older children.

1. Drug Therapy; This treatment can be applied in selected patients. Albendezole 2 mg/kg/day is given in this treatment. The drug has side effects and detailed information should be given on this subject. The drug is given for 3 weeks and then a week break is given, at the end of this period, some blood tests are performed for control. Ultrasonography in the 3rd month, ultrasonography and computed tomography in the 6th month. Treatment is planned according to the results. It should be kept in mind that drug treatment may take longer.

2. Interventional Intervention; Interventional intervention can be done in two main ways

   1. 1. PAIR (English Puncture, Aspiration, Injection, Reaspiration) consists of the first letters of the words.

      2. Surgical Procedure (Surgery)

         1. Laparoscopic Hydatid Cyst Surgery

         2. Open Hydatid Cyst Surgery

What is the PAIR Method?

Percutaneous Aspiration is an injection and reaspiration procedure. The details are mentioned below. However, if the cyst flows into the abdomen, it is a method that has the risk of spreading to other organs in the abdomen.

What are the Conditions (Contraindications) in which PAIR Method cannot be performed?

If the cyst has a connection to the biliary tract (cystobiliary fistula), percutaneous treatment with alcohol cannot be applied. Also if there are calcifications on the cyst wall.

How to Prepare the Patient for PAIR and Other Surgical Methods?

• Albendazole is used for at least 1 and preferably 3 months before the procedure. It continues for 3-6 months after the procedure.
• The patient's blood and other tests that need to be done before surgery are performed
• The family and older children are informed in detail about the method to be applied.
• Albendazole is given 2 mg/kg/day in children.
• Be prepared for anaphylactic shock.
• The patient is evaluated and informed by the anesthesiologist.

How is Percutaneous Hydatid Cyst Treatment (PAIR) Performed?

• The total volume of the cyst is measured before the procedure.
• Some of the fluid is drained with a needle inserted through the abdominal wall under ultrasonography guidance.
• Contrast material is injected into the cyst. It is evaluated on scopy. It is investigated whether there is a connection to the bile ducts (fistula). If it is decided that there is no fistula, treatment is continued.
• Hypertonic saline 30% of the total volume (hypertonic saline 20-30%) is given into the cyst. However, this may cause a condition called Hypernatremia in children. This can be life threatening especially for young children and care should be taken.
• It is determined that the endocyst is separated from the pericyst in the wall of the cyst.
• Wait for 15 minutes and aspirate the cyst content.
• Contrast material is given again and cystography shows that there is no extravasation (leakage).
• Approximately 70% of the total volume of 98% ethanol is administered into the cyst and waited for 15 minutes. High alcohol can cause acidosis in children, which can be life-threatening and should be treated with caution.
• All cyst contents are aspirated.

What are the Risks (Complications) of Percutaneous Hydatid Cyst Treatment (PAIR)?

• Cyst rupture (rupture)
• Abscess
• Fistula to the biliary tract
• Inflammation of the biliary tract (secondary sclerosing cholangitis)
• Spread of the cyst to other organs in the abdomen
• Allergy and Anaphylaxis

What are the Success Criteria in Percutaneous Hydatid Cyst Treatment?

• Decrease in cyst volume and size
• Decrease in the fluid component of the cyst
• Thickening and irregularity in the cyst wall
• Disappearance of the fluid component of the cyst and solid appearance of the cyst
• No increase in size in follow-up
• Calcification of the cyst

In cases where hydatid cysts are found in both the lung and liver (10-20%), surgical intervention is required for cysts in both organs. The surgeries should be performed in separate sessions and the hydatid cyst of the lung should be removed first.

Image: Intraoperative appearance of vesicles in hydatid cysts

What are the Complications of Liver Hydatid Cyst Surgery in Children?

• Cyst rupture (rupture), if necessary precautions are taken, especially in open surgery, this risk is quite low
• Abscess
• Fistula and bile leakage to the biliary tract
• Inflammation of the biliary tract (secondary sclerosing cholangitis)
• Spread of the cyst to other organs in the abdomen; If necessary precautions are taken, especially in open surgery, this risk is quite low
• Allergy and Anaphylaxis; This risk is low if the cyst is not ruptured.

How is the follow-up of patients who have undergone PAIR and surgery?

The patient uses Albenzol for about 6 months after surgery (open or laparoscopic). Blood tests and ultrasound are performed in the 1st and 3rd month after surgery. In the 6th month, Computerized Tomography is performed in addition to these tests. If there are criteria for using PIAR, the treatment is completed.

What are the Success Criteria for Percutaneous Hydatid Cyst Treatment?

The same criteria for PAIR criteria apply.

Does hydatid cyst heal on its own?

Hydatid cysts can be self-limiting for unknown reasons. If the capsule around the hydatid cyst is calcified, it means that the disease has cured itself. In this case, no treatment is required. Why this happens is not known. If the germinative membrane is somehow separated from the capsule, after a while the parasites in the cyst lose their vitality, do not grow, cannot reproduce and remain calcified.

What happens if hydatid cyst is not treated?

Except for cysts that are completely calcified, all patients must be treated with either interventional radiology or surgery. Otherwise, the disease progresses, the cyst(s) may grow and put pressure on the environment, interfere with digestion, cause jaundice, the cyst may rupture and cause anaphylaxis (an allergic reaction that may result in death), spread the disease into the abdomen, open the biliary tract, and become infected. All of these are life-threatening conditions and can be very difficult to treat.

Can hydatid cysts be treated with herbal methods?

Herbal methods are not valid in the treatment of hydatid cysts.

How to Prevent Hydatid Cysts?

• Raw foods should never be given to dogs and cats.
• Personal hygiene principles should be observed,
• Drinking and potable water should be clean,
• Vegetables and fruits eaten raw should be consumed after washing thoroughly with plenty of water.

 

 

Animal slaughter should be carried out in slaughterhouses and under the control of a veterinarian. The organs of slaughtered or deceased animals, especially those with water-filled pouches, should be buried and disposed of in a place inaccessible to dogs and other carnivorous animals. Particular attention should be paid to these issues during the sacrifice feasts.

• Owned dogs and cats should be treated for ‘echinococcus granulosus’ as required by special law, and if they defecate while being walked by their owners, the feces should be properly disposed of in the garbage.
• Stray dogs should be collected by the relevant persons in the municipalities and necessary actions should be taken.
• When dogs sniff each other's anuses, parasite eggs can be transferred to their noses and hair. Parasite eggs can be transferred to hands when stroking and petting free-roaming dogs without parasite control. The eggs of the parasite can be taken into the mouth without washing the contaminated hands. For this reason, especially children should not be allowed to play with stray dogs, and in case of contact, hands should be washed with plenty of soap and water.

The oncosphere in ‘Echinococcus granulosus’ eggs can be killed with hot water at 60°C in 10 minutes, at 70°C in 5 minutes and at 100°C in 1 minute.

*** The information provided here, the content of the website is intended to inform the visitor, especially families. No information should be considered as advice by visitors and should not lead to any decision or action. Families should definitely have a pediatric surgeon examine them, consult with him/her and make a decision by consulting his/her knowledge one-on-one.