Diagnosis and treatment of acute calculus cholecystitis: WSES 2020 Guideline

Diagnosis of ACC

• As no feature has sufficient diagnostic power to establish or exclude the diagnosis of ACC, it is recommended not to rely on a single clinical or laboratory finding.
• For the diagnosis of ACC, we suggest using a combination of detailed history, complete clinical examination, laboratory tests and imaging investigations. However, the best combination is not known.
• The researchers recommend the use of abdominal ultrasound (US) as the preferred initial imaging technique, in view of its cost-effectiveness, wide availability, reduced invasiveness and good accuracy for gallstones disease.
• The use of further imaging is recommended for the diagnosis of ACC in selected patients, depending on local expertise and availability. Hepatobiliary iminodiacetic acid (HIDA) scan has the highest sensitivity and specificity for the diagnosis of ACC as compared to other imaging modalities. Diagnostic accuracy of computed tomography (CT) is poor. Magnetic resonance imaging (MRI) is as accurate as abdominal US.

Tools to Use for Suspicion and Diagnosis at Presentation

• The use of elevated LFTs or bilirubin is not recommended as the only method to identify CBDS (common bile duct stone) in patients with ACC, in which case we recommend performing further diagnostic tests.
  
• Consider the visualization of a stone in the common bile duct at transabdominal US as a predictor of CBDS in patients with ACC.
• An increased diameter of common bile duct, an indirect sign of stone presence, is not sufficient to identify ACC patients with CBDS and we therefore recommend performing further diagnostic tests.
• In order to assess the risk for CBDS, we suggest performing liver function tests (LFTs), including ALT, AST, bilirubin, ALP, GGT and abdominal US in all patients with ACC.
• Stratifying the risk of CBDS is suggested according to the proposed classification modified from the American Society of Gastrointestinal Endoscopy and the Society of American Gastrointestinal Endoscopic Surgeon Guidelines.
• The patients with moderate risk for CBDS are recommended to undergo one of the following: preoperative magnetic resonance cholangiopancreatography (MRCP), preoperative endoscopic ultrasound (EUS), intraoperative cholangiography (IOC), or laparoscopic ultrasound (LUS), depending on local expertise and availability.
• Patients with high-risk for CBDS are recommended to undergo preoperative ERCP, IOC or LUS, depending on the local expertise and the availability of the technique.
• Removing CBDS is recommended, either preoperatively, intraoperatively, or postoperatively, according to the local expertise and the availability of several techniques.