Minimally invasive surgery usually requires drainage for about two months if a T-tube is placed inside the common bile duct. For previous open surgery, a T-tube can be placed in the common bile duct for about fourteen days. If a cholangiogram reveals that the lower bile duct is patent, the T-tube can be removed. But nowadays, minimally invasive surgery is usually done, which means laparoscopic cholecystectomy or combined laparoscopic choledochotomy with placement of a T-tube. Since minimally invasive surgery has less impact on the abdomen, the formation of sinus tracts around the T-tube is usually late after surgery, and if the T-tube is removed after fourteen days, it may lead to bile leakage. Therefore, it is better to be conservative to have another T-tube imaging two months after the surgery, or you can directly do a cholangioscopy to observe the patency of the lower bile duct.