Situs Inversus Totalis: Challenges and Anatomical Considerations in Endoscopic Retrograde Cholangiopancreatography

Situs inversus totalis (SIT) is a rare condition characterised by the reversed positioning of abdominal and thoracic viscera. The anomaly poses a significant anatomical challenge during routine endoscopic procedures, including endoscopic retrograde cholangiopancreatography (ERCP). Here, we present the case of a 51-year-old patient with SIT and obstructive jaundice due to a periampullary mass. Initial ERCP attempts at an external facility for biliary decompression were unsuccessful, prompting referral to our center. Multidisciplinary consensus recommended preoperative ERCP followed by a Whipple's procedure. ERCP was performed with positional adjustments (prone position) of the patient and significant scope manipulation (stepwise 360-degree anticlockwise rotation) to navigate the reversed anatomy. Cannulation was achieved, and a plastic biliary stent was placed, resulting in effective drainage. The patient demonstrated clinical improvement and was referred for surgical intervention. A comprehensive understanding of the reversed anatomy, along with the operator's skill and experience, is essential to address the challenges posed by this unique anatomical variation.