Complex sentence: Riedel was a pioneer in the surgical treatment of appendicitis and cholecystitis, and in 1888 is credited with performing the first choledochoduodenostomy (anastomosis of the common bile duct to the duodenum).
Split into simpler sentences: Riedel was a pioneer in the surgical treatment of appendicitis and cholecystitis. In 1888 he performed the first choledochoduodenostomy (anastomosis of the common bile duct to the duodenum).