From cystic duct to static mixer: A serendipitous journey via flow visualization

The cystic duct is a very complicated conduit that connects the gallbladder to the common bile duct. The geometry of the of the cystic duct and its functions, in particular the valves of Heister, in the flow of bile into and out of the gallbladder have always been a subject of speculation. It has been suggested variously that their function is to: impede the flow of bile into the gallbladder, prevent the outflow of bile from the gallbladder, or prevent the collapse of cystic duct. Presented in this paper is the results of a novel experiment to assess the role of the valves of Heister during both the filling and the emptying phases of the gallbladder. The results suggest that the existence of these valves helps both the filling and the emptying of the gallbladder by providing structural support and preventing the duct from total collapse. A surge of pressure upstream of the cystic duct is observed prior to the opening of the cystic duct which is consistent with previous in-vivo biological observations