The Utility of Endoscopic Ultrasound in Detecting Missed CBD stones

Background: Precise techniques for identifying common bile duct (CBD) and pancreatic disorders are crucial to strategize appropriate interventions. This study aimed to assess the utility of endoscopic ultrasound (EUS) and magnetic resonance cholangiopancreatography (MRCP) in detecting CBD stones compared to endoscopic retrograde cholangiopancreatography (ERCP). Methods: This prospective multicenter research included 200 patients over 18 years old with dilated CBD measuring 6-10 mm, unexplained elevated liver enzymes, and unexplained acute pancreatitis. The patients were evaluated using abdominal ultrasonography, MRCP, and EUS. MRCP is performed just before the EUS and the ERCP being performed at a subsequent stage whenever indicated. Results: Stones were detected in 39.5% of the patients using ERCP compared to 47% using MRCP and 43.5% using EUS. There was a strong agreement between ERCP findings and EUS findings (Kappa=0.837). EUS can significantly detect stones with a sensitivity of 94.9%, specificity of 90.1%, positive predictive value (PPV) of 86.2%, Negative predictive value (NPV) of 96.5%, and accuracy of 92%. There was a moderate agreement between ERCP findings and MRCP findings (Kappa=0.402). MRCP can significantly detect stones with a sensitivity of 72.2%, specificity of 69.4%, PPV of 60.6%, NPV of 79.2%, and accuracy of 70.5%. The accuracy of EUS was significantly higher than accuracy of MRCP. Conclusions: EUS is a more accurate diagnostic tool for detecting stones compared to MRCP, and it has a strong agreement with ERCP findings, which is considered the gold standard??