The liver has various functions. Production of bile is one of these functions. Bile is necessary for digestion of fat and removal of certain waste byproducts from the liver. The bile produced in the liver is stored temporarily in the gallbladder. On eating fatty food, the gallbladder releases the bile into the small bowel. The common bile duct is the tube through which bile flows from the liver to the gallbladder, and from there to the small bowel. Stones can obstruct the flow of bile from the gallbladder into the small bowel. Usually such stones are formed in the gallbladder and migrate into the common bile duct. Obstruction of the flow of bile can lead to jaundice. Such stones are usually removed using an endoscope (by introducing an instrument equipped with a camera through the mouth and into the small intestine) before keyhole removal of gallstones (laparoscopic cholecystectomy) or as a part of the keyhole removal of gallstones (laparoscopic common bile duct exploration). Laparoscopic common bile duct exploration can only be performed in highly specialised centres and so endoscopic removal of common bile duct stones is the commonly used method to treat stones in the common bile duct. However, when such endoscopic treatment fails the patient has to be subjected to open common bile duct exploration. This involves exploring the common bile duct using instruments or a camera, or both, which are introduced into the common bile duct usually through a cut in the common bile duct. After the stones are removed, the hole in the common bile duct has to be stitched. Traditionally, surgeons have used a T-tube through the cut in the common bile duct. The T-tube is shaped like the English letter 'T' as the name indicates. The top part of the letter 'T' is inside the common bile duct while the long bottom part of the letter 'T' is brought out of the tummy through a small cut and is connected to a bag. This tube is inserted with the intention of preventing the build-up of bile in the common bile duct due to temporary swelling, which is common after any cut in any part of the body. The build-up of bile along with the swelling can potentially prevent healing of the bile duct resulting in leakage of bile from the common bile duct into the tummy. Uncontrolled bile leak into the abdominal cavity can be life-threatening if this is not recognised and treated appropriately. In addition to acting as a drain, draining the bile from the common bile duct to the exterior, dye can be injected into the T-tube and an X-ray used to demonstrate any residual stones. Once the absence of residual stones is confirmed, the T-tube is removed. However, surgeons are concerned about the tiny hole which the T-tube leaves on removal. This tiny hole in the common bile duct normally heals without a trace, but in some patients bile can leak through the hole and cause the very problem that the T-tube was meant to prevent. Thus the use of a T-tube after open common bile duct exploration is a controversial issue. We attempted to answer the question whether primary closure (stitching the cut in the bile duct without a T-tube) is better than using a T-tube after open exploration of the common bile duct by reviewing all the available information in the literature from randomised clinical trials. Randomised clinical trials are special types of clinical studies which provide the most valid answers if performed correctly.

We identified a total of six trials including 359 participants of whom 178 had primary closure and 181 patients had T-tube drainage after open exploration of the common bile duct. All six trials were at high risk of bias (risk of overestimating the benefits and underestimating the harms of the intervention or the control). There was no significant difference in mortality (12 deaths per 1000 participants in the T-tube drainage group versus 6 deaths per 1000 participants in the primary closure group) or in the serious complication rate after surgery between the two groups (approximately 145 complications per 1000 participants in the T-tube drainage group versus 66 complications per 1000 participants in the primary closure group). Although the number of deaths and complication rates in the primary closure group appeared to be less than half those in the T-tube group, there is a possibility that this was not a true observation but rather a difference that occurred by chance (similar to there being one chance in eight of flipping a coin and having it come up heads or tails three times in a row). For this reason we cannot be sufficiently confident that a true effect exists, and we term such a difference as not being statistically significant. None of the trials reported quality of life or the time taken for patients to return to work. The average operating time was significantly longer in the T-tube drainage group than in the primary closure group (by about 30 minutes). The average hospital stay was significantly longer in the T-tube group than in the primary closure group (by about five days). Use of a T-tube appears to increase the cost without providing any benefit to the patients. Further randomised trials with low risk of bias (low chance of arriving at the wrong conclusions because of prejudice by healthcare providers, researchers, or patients) and low risk of random errors (arriving at wrong conclusions because of chance) are necessary to confirm whether the use of T-tubes is justified anymore. Until the results from such trials are available, we discourage the routine use of T-tube after open common bile duct exploration.