Acute calculous cholecystitis (ACC) is the second most frequent surgical condition in emergency departments, the complication rate of ACC is 8-20%, and the mortality rate is 0.5-6% in recent series. The Tokyo Guidelines (TG) advocate for different risk factors and initial treatments of ACC with no clear evidence that all patients will benefit from them.

The objective of the study is to identify the risk factors for complications in ACC.

It is a retrospective cohort study conducted from January 2011 to December 2016 in a single center with a dedicated surgical emergency unit in a Metropolitan University Hospital in Barcelona, Spain. The analysis of the data was finished in March 2020.

The study candidates comprised 963 consecutive patients with a diagnosis of ACC according to the TG18 and/or received a diagnosis of ACC in the Pathology report in those that an emergent cholecystectomy was performed.

The study case definition was a 'Pure Acute Cholecystitis' (pure ACC); therefore, patients with any other concomitant diagnosis potentially influencing outcome (Postoperative cholecystitis, Acute Cholangitis, Acute Pancreatitis, Incidental Cholecystectomy, Acalculous Cholecystitis, Chronic Cholecystitis/Persistent Colic, Post-endoscopic retrograde pancreato-cholangiography, or Neoplasia) were excluded from the final analysis.

Variables:

Primary data were available from a prospective database maintained in File Maker v.12 (Mountainview, CA, USA), which included basic demographic data, type of interventions, sex, days of admission, and complications. Every record was completed by browsing the electronic patient record, adding laboratory and microbiology data, as well as antibiotic therapy, duration of procedure, additional procedures, and grade of acute cholecystitis according to the TG18 diagnostic criteria.

Preoperative comorbidities were assessed using the Charlson Comorbidity Index and surgical risk by ASA classification. The type of initial treatment was classified as Surgical Treatment (Cholecystectomy either by laparoscopy or laparotomy) or Non-Surgical Treatment, which was either percutaneous cholecystostomy or intravenous antibiotics alone.

The main outcome measure was the mortality after the diagnostic of ACC. In the patients that were discharged, 30 days after the diagnosis, if the patients was not discharged in 30 days, at any time during the same admission.

Interventions:

All patients received intravenous antibiotic therapy from the moment the diagnosis was formulated, according to a fixed protocol.

Ultrasound-guided cholecystostomy was performed percutaneously with an 8-Fr catheter (SKATER ™, Argon Medical Devices, Rochester, NY, USA) by either transhepatic or transperitoneal insertion, at the discretion of the radiologist.

Laparoscopic Cholecystectomy was performed according to the French technique using 4 trochars. The content of the gallbladder was evacuated by Veress needle puncture when necessary.

Statistical Analysis:

The discrimination power of the model was assessed by receiver operating characteristic (ROC) curves and was compared with the DeLong method.

Legal and Ethical considerations This study was approved by the clinical research ethical committee of the Hospital del Mar and was classified as a non-clinical trial.

Inclusion Criteria:

• Diagnostic of a "Pure" Acute Calculous Cholecystitis.
• Older than 18 years old.

Exclusion Criteria:

• Younger than 18 years old.
• Any concomitant diagnostic that could change the prognostic of a "Pure" ACC, for example: Cholangitis, Pancreatitis, Postoperative ACC, Acalculous cholecystitis.

All patients admited with a diagnostic of Acute Cholecystitis in a dedicated surgical emergency unit, from January 2011 to December 2016, in a Metropolitan University Hospital in Barcelona, Spain.

all primary and secondary variables of anonymized individual data set will be provided

May 2021 to May 2022

any researcher