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 gallbladder 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 to the flow of bile can lead to jaundice. Such stones are usually removed by inserting an endoscope (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 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 the common bile duct stone is the commonly used method to treat stones in the common bile duct. Laparoscopic common bile duct exploration 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 but they seal the cystic duct if the exploration is performed through the cystic 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 'T' is brought out of the tummy through a small cut and 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 the healing of the bile duct resulting in a leakage of bile from the common bile duct into the tummy. Uncontrolled bile leak can be potentially life-threatening if this is not recognised and treated appropriately. In addition to acting as a drain, which drains 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 this hole and cause the very problem that the T-tube was meant to prevent. Thus, the use of a T-tube after laparoscopic common bile duct exploration is a very controversial issue. We have attempted to answer the question whether T-tube drainage is better than primary closure (stitching the cut in the bile duct without a T-tube) after laparoscopic exploration of common bile duct by reviewing all the available information from randomised clinical trials that is in the literature. Randomised clinical trials are a special type of clinical study which provides the most accurate answer if performed correctly.

We identified a total of three trials including 295 participants, of whom 148 were randomly chosen to receive primary closure and the remaining patients had T-tube drainage after laparoscopic exploration of common bile duct. All three trials were at high risk of bias (risk of underestimating or overestimating the benefits and harms of the intervention). There were no deaths in either group. There was no significant difference in the serious complication rate (approximately 97 complications per 1000 patients in the T-tube group versus 61 complications per 1000 participants in the primary closure group) or in the proportion of participants who developed serious complications (11.3% in the T-tube group versus 6.2% in the primary closure group). Although the complication rates in the T-tube group appear to be twice as high as those in the primary closure 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 four times in a row). For this reason, we cannot be sufficiently confident scientifically that these differences were not just due to chance and that is the reason why we have stated that there was no 'significant' difference. Of course, if such a difference truly exists, it would be clinically important. None of the trials reported the quality of life of the participants. The average operating time was significantly longer in the T-tube group than in the primary closure group (by about 20 minutes). The average hospital stay was significantly longer in the T-tube group than in the primary closure group (by about three days). Participants returned to work significantly later in the T-tube group than primary closure group (by about eight days). Use of 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 wrong conclusions because of prejudice by healthcare providers, researchers, or patients) with longer follow-up period are necessary. Until the results from such trials are available, we discourage the routine use of T-tube after laparoscopic common bile duct exploration.