What are the valves of Heister?
The spiral folds of mucous membrane in the wall of the cystic duct; their function is believed to be one of preventing sudden distention of the cystic duct when the pressure in the gallbladder or cystic duct rises.
Surgical Anatomy. Arch Surg. 1997;132(11):1176. doi:10.1001/archsurg.1997.01430350026004