Hydatid cysts are caused by the infection of a parasite called echinococcus. Echinococcus is usually transmitted by ingestion of raw vegetables and fruits that have come into contact with dog feces. The most commonly involved organ is the liver, and more rarely the lung, spleen and kidney. However, hydatic cysts may occur in every organ in the body, including the brain and bone.
How is it diagnosed?
Hydatic cysts can be diagnosed by typical imaging findings of ultrasonography, CT or MRI, taken on clinical suspicion or for unrelated reasons. In addition, the "echinococcus test" in the blood can support the diagnosis. In most hydatid cysts, imaging findings are typical, but can sometimes be confused with simple cyst, abscess, biloma (biliary cyst) and hematoma (cyst filled with blood).
What happens if not treated?
Hydatid cysts can grow, multiply, get infected, or rarely burst into the abdominal cavity if they are not treated. In such cases, a severe and dangerous allergic reaction called anaphylaxis may develop.
How is it treated?
Drugs such as Albendazol, Mebendazol may be administered in hydatid cyst, but drug treatment alone is not very effective. But it is used today to reduce the risk of spread before and after the intervention. The most commonly used treatment modalities in the treatment of hydatid cysts are "percutaneous treatment" and classical surgical operation. The type of treatment should be decided individually in each patient based on imaging and clinical findings. According to these imaging findings, the hydatid cysts are divided into 5 types (Gharbi Classification). In Type 1 and 2, percutaneous treatment is ideal whereas in type 3 and 4, surgery is more appropriate although in Type 3, percutaneous treatment can also be tried. Type 5 means healed hydatid cyst, so no treatment is necessary.
In hydatid cyst, percutaneous treatment should be preferred whenever possible. Because, the risks and side effects of percutaneous treatment are much lower than surgical treatment. In addition, absence of general anesthesia, surgical incision and hospitalization are other additional advantages. Therefore, in hydatid cyst patients, surgical treatment should be considered only in patients in whom percutaneous treatment is unsuitable or unsuccessful.
Non-surgical (percutaneous) treatment:
For percutaneous treatment, first Albendazol is started 1-2 weeks before the procedure. On the day of the procedure, a thin needle is inserted into the cyst under ultrasound guidance and local anesthesia. If the cyst is a simple hydatid cyst with a diameter less than 6 cm, the cyst fluid is removed, then the parasites are killed by giving hypertonic saline at a concentration of 20-30%. Then, the liquid in the cyst is taken out and alcohol is given to destroy the cyst wall the needle is removed. After that the cyst content is aspirated again, the needle is taken out and the procedure is ended.
If the cyst is above 6 cm in diameter, the above treatment can be applied, or a thin tube called catheter is placed in the cyst and the fluid is poured into the bag for several days. When the amount of liquid coming into the bag is reduced, the drug is administered first to check if the cyst is connected to the bile ducts. If there is no connection, hypertonic saline and alcohol are given and the catheter is taken out.
In type 2 and some type 3 hydatid cysts, treatment with needle alone is not sufficient. In such cysts, a thicker catheter is first inserted into the cyst and by flushing vigorously with saline, the solid structures in the cyst are dissolved. Then, classical catheter treatment is performed in the same manner.
Interventional oncology in cancer management
Prof Saim Yilmaz, MD