Changes in gallbladder volume do not affect cystic duct resistance.

To our knowledge, the relationship between gallbladder volume and cystic duct function has not been studied. We hypothesized that changes in gallbladder volume would influence cystic duct resistance. The effect of gallbladder volume changes on cystic duct resistance to both prograde (emptying) and retrograde (filling) steady-state flow was tested in 12 dogs under basal cholecystokinin-stimulated conditions utilizing a multiport catheter with a highly compliant balloon placed within the gallbladder fundus. Gallbladder volume was regulated by varying balloon volume from empty to just beyond physiologic distention. Cystic duct resistance was not affected by balloon volume under basal or stimulated conditions or by the direction of perfusate flow. This study demonstrated no relationship between gallbladder volume and cystic duct resistance and did not demonstrate a cystic duct sphincter mechanism at physiologic gallbladder volumes.