Investigations on common bile duct stones.

Common bile duct stones from 59 consecutive patients who underwent cholecystectomy more than 1 year before radiological detection of choledocholithiasis (group I) and from 31 consecutive patients with choledocholithiasis and gallbladder in situ (group II) were subjected to chemical analysis and compared with the composition of gallbladder stones from the same population (two consecutive biopsy and autopsy series, n = 343). In contrast to cholecystolithiasis, inorganic calcium salts were infrequent in choledocholithiasis while calcium bilirubinate and fatty acid calcium salts played an important role in the composition of common bile duct stones. This is of particular importance in terms of litholysis. With respect to stone pathogenesis, clinical and radiological data were analyzed, as was hepatic bile lipid composition. There was no significant difference in the lithogenic index (percent cholesterol saturation) in cholecystectomized and in non-cholecystectomized patients with choledocholithiasis. The most important cause of stone recurrence in the common duct after surgery was incrustation of unabsorbed suture material, which was the case in 30.5% of group-I patients.