The goal of this observational study is to compare the results in terms of morbidity and disease-free survival between groups of patients with liver cystic echinococcosis (LCE) managed with radical surgery (RS) or conservative surgery (CS), and to evaluate potential risk factors of clinically relevant biliary fistula and liver recurrence.

Main hypothesis:

1. Radical surgery (RS) in LCE has better postoperative results than conservative surgery (CS) in terms of global morbidity, specific morbidity and liver recurrence rate.

   Secondary hypotheses:

2. It is possible to identify preoperative and intraoperative prognostic factors of higher morbidity and recurrence rate.

3. The location of the residual pericystic layer in CS is related to a higher incidence of liver recurrence.

4. The percentage of residual pericystic layer in CS is related to a higher incidence of postoperative biliary fistula.

Main outcome:

1. To assess the incidence of liver recurrence between the RS and the CS groups, identifying potential risk factors.
2. To evaluate the incidence of postoperative biliary fistula between the RS and the CS groups, identifying possible risk factors.

Secondary outcomes:

1. To estimate the incidence of overall morbidity related to surgery.
2. To estimate the incidence of specific morbidity related to surgery (biliary fistula, intra-abdominal abscess, residual cavity abscess, hemoperitoneum, incisional infection, liver failure, respiratory infection, others).
3. To specifically analyze the incidence of postoperative biliary fistula and complex biliary fistula, and identify possible risk factors.
4. To estimate the incidence of mortality related to surgery.
5. To estimate the rate of hepatic and extrahepatic recurrence (number of disease-free months)
6. Prepare a recommendation for a standardized management algorithm for LCE patients based on the results obtained in the study and make it applicable to clinical practice.

Inclusion Criteria:

• Adult population (18 years or older) of both sexes surgically intervened for a diagnosis of LCE at the Bellvitge University Hospital and during the period described using a conservative or radical technique.
• Patients with asymptomatic liver hydatid cysts of active type or transition CE1 to CE3 according to the WHO classification.
• Patients with symptomatic or complicated hepatic hydatid cysts of any type (CE1 to CE5) according to the WHO classification.

Exclusion Criteria:

• Patients under 18 years of age.
• Patient operated on for LCE diagnosis with inactive asymptomatic cysts (CE4 or CE5 according to the WHO classification).
• Patients with less than 1 year of follow-up.

A prospective analysis of patients who undergo surgery for LCE from January 1996 to December 2021 at the Hepatobiliary Surgery and Liver Transplantation Unit of the Bellvitge University Hospital.