Needle-knife fistulotomy

This patient underwent ERCP, which demonstrated bile duct stones and a bulging papilla (A). Needle knife fistulotomy was performed by initiating the incision midway up the papilla in the center where the bile duct lies (B). The incision was extended upwards (but the direction can also be downwards) until the circular muscle fibers of the bile duct were visualized and cannulated (C).