**6. Percutaneous techniques**

*Overview on Echinococcosis*

under treatment.

initial treatment for small, asymptomatic cysts.

**5. Interventional treatment algorithm**

more diligently, increasing the number of drains, etc.).

uncertain but is better than that of mebendazole, and albendazole can be used as an

The standard dose of mebendazole is 35–50 mg/kg/day, and the standard administration period is 6 months, whereas albendazole's standard dose is 10 mg/ kg/day. Albendazole is more effective than mebendazole, because it has better absorption from the gastrointestinal tract, reaching much higher concentrations in both serum and cyst fluids. Therefore, the daily dose of albendazole is lower. However, it has toxic effects on the liver and bone marrow. For this reason, liver function tests and hemogram should be performed periodically in the patients

Even if the management of the patient is decided as operation, the administration of albendazole for 1 month preoperatively reduces the number of viable vesicles within the cyst and reduces the risk of surgical scattering/recurrence.

In the majority of the patients, the medical treatment of the hydatid cyst is applied first, both for the treatment of the disease and for reducing the rate of the complications even if the cure is going to be reached by the surgical procedures. The effectivity of the medical treatment can be assessed in two ways. By radiological assessment, USG can be performed, and if the cyst diameter does not increase and/or calcification is developed, the medical treatment is successful. By the serological assessment, the IHA test is repeated after 6 months of treatment. Regardless of the stage, special attention should be paid to the content of each cyst. Cysts, in which the content is biliary or purulent, deserve additional interventions (finding and suturing the biliary tract (s) opened to the cyst, making drainage

Even if the risk is first defined as 25% in literature [4], 5% of the cases with

Occasionally, the cysts spontaneously tear into the peritoneal cavity and cause anaphylaxis, which starts with abdominal pain. Many intra-abdominal cysts may develop as a result of intraperitoneal leakage. Liver hydatid cysts can penetrate the diaphragm and cause empyema, pulmonary cysts, biliary bronchial fistulas, or

Some hydatid cyst disintegrates into bile ducts and may simulate choledocholithiasis. If the calcified cyst is unclear, cholangiography may show significant irregularities in the caliber of biliary ducts and large displacement of intrahepatic branches secondary to the mass effect of a large hydatid cyst [5, 6]. Before the interventions, if the patient has signs of jaundice and/or cholangitis, preoperative MRCP and ERCP, if necessary, should be definitely evaluated for the presence of the cyst opening to the biliary tract or the presence of cysts in the biliary tract. This

The general rule is that surgical treatment is indicated for cysts larger than 5 cm. However, there are controversial issues such as attempting medical treatment first or applying medical treatment if there already occurred calcification on the wall. The discussion remains under the knowledge of the physiology of the cyst.

procedure is very important in determining the surgical strategy.

indication for surgery are associated with bile ducts. This risk is greater in multivesicular cysts. Biliary entrances may result from communication between the pericyst and the biliary tract or from rupture of the cyst into the biliary tract. Strong communication of the cysts and bile ducts can lead to secondary bacterial infection of the cyst, cholangitis, or biliary obstruction. Bacterial contamination occurs in 10–35% of cases, and almost all of the infected cysts are associated with

**104**

bile ducts.

pericardial collections.

Traditionally, surgery has been the recommended treatment for hepatic cysts since the 1996 World Health Organization Consortium [7], but the combination of percutaneous drainage with drug therapy is always an alternative. Although percutaneous aspiration is contraindicated due to the risk of anaphylaxis, this complication has been shown to be rare for many years [8, 9]. Initially, a catheter was inserted for percutaneous drainage, and a cystolytic agent was injected into the cyst cavity after cystography. No complications or recurrences were reported 6 months to 1 year after treatment.

If percutaneous drainage is planned for the patient, it is important to remember that hydatid cysts do not resolve by aspiration just like any cyst. Recurrence is almost inevitable when only aspiration is performed. Therefore, a percutaneous technique called PAIR (perforation, aspiration, injection, reaspiration) can be used concurrently with albendazole treatment, which is found to have several advantages over surgical resection. In this method, after ultrasound-guided percutaneous perforation and aspiration of the hydatid cyst, 20% sodium chloride solution or 95% ethanol is injected into the cavity and then reaspired [10]. This intervention can be done twice or more in the same session to reduce the cavity of the cyst.

According to the Gharbi classification, PAIR can be applied for stage 1 and 2 diseases, whereas care should be taken for stage 3 diseases not to remain any vesicles inside. For stages 4 and 5, it is not expected for the cyst to collapse and close itself, because of the calcification and the irregularity of the wall [11]. In such cases, if surgical intervention has been performed, at least one of the cavity-minimizing and secretion-reducing procedures such as omentoplasty, capitonnage, and intraflexion must be added to the procedure after the removal of the germinative and laminar membranes.

First, Khuroo et al. [12] compared percutaneous drainage of hepatic hydatid cysts with surgery and reported that percutaneous drainage with albendazole was an effective alternative to cystectomy. They found that percutaneous drainage showed similar efficacy in the regression and loss of cysts with the advantages of shorter hospital stay and low complication rate.

Zerem and Jusufovic treated 72 patients with univesicular and multivesicular hepatic hydatid cysts with percutaneous drainage by imaging with albendazole, and 81% of the cysts in the univesicular group and 63% of the multivesicular group were cured.

As a derived technique, Schipper et al. reported in 2002 that percutaneous evacuation of cyst content (PEVAC) is a safe and effective treatment for multivesicular echinococcal cysts with or without cystobiliary fistula, even though it is not used nowadays.

Hydatid cysts usually communicate with the biliary tree, which is a contraindication to the injection of sclerosing agents, as this may cause widespread injuries to the biliary epithelium [3].

### **7. Surgical procedures**

The main purpose of surgical treatment in liver hydatid cyst is to eliminate the parasite, to prevent recurrence of the disease, and to minimize the complication and mortality by removing the germinative and laminar membranes. If the germinative membrane stays, asexual reproduction occurs, which is currently the actual recurrence reason of the cysts. Even if there are no vesicles left, sterile cysts may occur in the main location [13].

#### *Overview on Echinococcosis*

The main question here is: Is it necessary to remove the entire cyst, or is it sufficient to remove only the cyst? Two treatment modalities have therefore been proposed: radical and conservative surgery. The choice of surgical treatment depends on the number, localization, diameter, and complexity of the hydatid cysts, as well as the age and comorbidities of the patient, and the experience of the surgeon.
