82 year-old woman with chronic biliary obstruction caused by two large common bile duct stones. The distal common duct had spontaneously drained via a fistula across the ampullary wall and into the duodenum.

LEFT: The ampulla with cannula in place. Contrast injected through the cannula flows back into the duodenum through the fistula tract located on the side wall of the ampulla.

RIGHT: After papillotomy, the larger of the two common duct stones being extracted into the duodenum using the papillotome.