LAUSR

Exploration of the common bile duct is still a far from satisfactory operation. About 100 000 such procedures are done every year in the United States alone, and in at least 100/0 of these explorations' stones will be left behind; in a further, smaller but unknown, number of patients stones will form again. Nevertheless, considerable progress has been made in developing techniques for preventing and treating overlooked and recurrent common duct stones. To avoid overlooking stones in the common bile duct the surgeon must, firstly, recognise all ducts that contain stones and explore them; secondly, he must extract all stones from the ducts explored; and, finally, he needs to recognise that small percentage of patients in whom stones are likely to form again and to do something to prevent this. Until 15 or 20 years ago the decision to explore the common duct was made on clinical criteria. The absolute indications were the presence of jaundice, a dilated biliary tree, or a palpable stone, and the relative ones included the presence of multiple small stones, a history of jaundice, or a history of pancreatitis. This policy has changed since operative cholangiography has become routine, for now a surgeon can expect routinely to get x-ray films of good quality to show whether there are any of the abnormalities which require exploration of the common duct-namely, stones within the duct system, dilatation of the duct system, or a failure of contrast to flow readily into the duodenum. The use of operative cholangiography has, then, meant that fewer ducts are being explored and a much higher proportion are yielding stones.2 Some surgeons have claimed that manometry of the bile ducts is as accurate, but this technique has not found general acceptance and has the disadvantage that there is no permanent visual record of the common duct for future reference. The actual exploration of the duct requires painstakingly careful technique. Adequate exposure is essential, and this means complete mobilisation of the second part of the duodenum (Kocher's manoeuvre). The duct is gently explored with stone forceps and irrigated with saline through fine catheters. A fine balloon catheter is useful for extracting stones from the liver or from the lower end of the duct. The forceful use of dilators or other metal instruments is contraindicated, and if a stone is firmly impacted at the lower end of the duct the duodenum should be opened and the ampulla incised to allow it to be extracted without undue force. In a