The goal of this clinical trial is to compare outcomes for interval or early laparoscopic cholecystectomy in patients with moderately severe and severe pancreatitis. The main question[s] it aims to answer are:

• To establish whether there is a difference in surgical outcomes comparing patients diagnosed with severe or moderately severe pancreatitis on which early cholecystectomy was performed versus performing interval cholecystectomy.
• The primary endpoint will be to evaluate major complications, defined as a Clavien-Dindo score greater than or equal to III/V.
• Secondary endpoints include evaluating minor complications (defined as a Clavien-Dindo score below III/V), biliary disease recurrence, mortality, postoperative hospital stay and postoperative admittance into an intensive care unit.

Participants will be randomly assigned to either group: early cholecystectomy during the pancreatitis hospitalization or interval cholecystectomy scheduled 4 weeks after clinical resolution of pancreatitis.

CHISPA is a randomized controlled, parallel-group, superiority clinical trial. An intention- to-treat analysis will be performed. It seeks to evaluate differences between patients taken to early cholecystectomy during hospital admission (72 hours after randomization) versus delayed cholecystectomy (30 +/- 5 days after randomization). Primary endpoint is major complications associated to laparoscopic cholecystectomy defined as a Clavien-Dindo score of over III/V during the first 90 days after the procedure. Secondary endpoints include recurrence of biliary disease, mortality, minor complications (Clavien-Dindo score below III/V), days of postoperative hospital stay, and days admitted in an intensive care unit postoperatively.

Inclusion Criteria:

• Age ≥18 years, diagnosis of pancreatitis according to Atlanta guidelines, moderately severe or severe pancreatitis (APACHE score ≥8 on admittance)
• Biliary pancreatitis diagnosed on imaging (be it ultrasound, magnetic resonance imaging and/or tomography)
• Recovery of pancreatitis by tolerance of oral intake (defined as 24 hours of food consumption of any consistency without emetic episodes and pain defined as 4/10 on the visual analogue score of pain) and written informed consent.

Exclusion Criteria:

• Pregnancy
• History of cholecystectomy
• Planned open cholecystectomy
• Pancreatitis-associated complication before laparoscopic cholecystectomy (compartment syndrome, bleeding and/or need for peripancreatic collection drainage)
• Chronic pancreatitis,
• More than one episode of pancreatitis
• Active malignant disease
• Septic shock
• Choledocholithiasis not resolved by ERCP, post-ERCP perforation and post-ERCP concomitant pancreatitis.

Data obtained and input into the database is anonymous, without any individual or identifying characteristics will be stored in a dataset from the Centro de Recursos para el Aprendizaje y la Investigación, property of and administered by the Universidad del Rosario as a plan of data management. Moreover, the different codes used in the analysis will be stored in this dataset.

It is in our plans once we obtain a register number from Clinical Trials in order to publish the protocol, statistical analysis plan and clinical study report in a scientific journal so it will be available to all people interested.

It is in our plans to be published in a scientific journal available to all people interested.