After cholecystectomy, common hepatic duct slightly dilates and serves as a bile reservoir, without simultaneous dilation of small intrahepatic bile ducts and laboratory signs of cholestasis.
For the clinician, it is quite interesting that dilation of bile ducts does not necessarily correspond to a diagnosis of obstructive icterus and mainly that bile ducts experiencing higher pressure ahead of obstruction may be of regular width. In other words, the absence of bile ducts dilation does not exclude obstruction of bile flow as a cause of icterus!
Here some examples from the abdominal sonography: