The catheter should be advanced down to the papilla into the duodenum. It position is confirmed with fluoroscopy showing the catheter marker above the papilla. Catheter entrapment is the cause of bleeding and pancreatitis. The basket is then opened and under fluoroscopic guidance the stone is engaged, applying a rotational movement to the basket while pulling out. If the stone is too big to pass the cystic duct, more pressure should be applied to the basket wires with the goal of fragmenting the stone.
More contrast material is used to verify the anatomy and the obstruction.
In this picture the stone has been retrieved and placed into a bag. A cholangiogram is performed at termination of the procedure to verify ductal stone clearance and free passage of contrast material to the duodenum. Notice the pancreatic duct joining the CBD into a common duct. An impacted stones in this area will increase the pancreatic duct pressure, mechanism proposed to explain pancreatitis in this particular setting. The cystic duct is ligated with an Endoloop to ensure a tight closure.