Structure and composition of common bile duct stones in relation to duodenal diverticula, gastric resection, cholecystectomy and infection.

BACKGROUND: Common bile duct stones represent a clinical problem often involving severe infection, cholangitis and cholestasis. Stasis and infection are thought to play a part in the pathogenesis of choledocholithiasis. Investigations on the etiology of common bile duct stones are, however, scarce because of the difficult access to common bile duct stones and bile. In a clinical series of common bile duct stones, we studied the gross appearance of stones extracted endoscopically from the common bile duct and measured the cholesterol and bilirubinate content in order to elucidate factors of importance to etiology.
METHODS: In 135 patients treated endoscopically for bile duct stones, the stones or parts of the stones were collected. Appearances of the cut surface of the stones were studied and described. Cholesterol and bilirubinate content were analyzed enzymatically and with infrared spectroscopy. The growth in bile of gas-producing bacteria previously shown to be correlated with enterobacteriacea was investigated.
RESULTS: Seventy-five percent of the stones were pigment stones, the majority with concentric pigmented layering. There was good agreement between cholesterol measurements. With a cutoff at 50% for the infrared measurements and 25% for the enzymatic assay only 3 stones were discordant between cholesterol measurements and visual inspection. Twenty-one of 23 patients with a previous Billroth-II gastric resection had pigment stones (p < 0.05). Gas-producing bacteria were significantly more prevalent in the bile from patients with layered pigment stones.
CONCLUSION: Pigment stones with concentric layering highly suggestive of a cyclic process of crystallization were recovered from the common bile duct in 70% of the patients in our series. Copyright 2000 S. Karger AG, Basel