[Cholesterol crystals and biliary lithiasis. Importance of the study of bile collected by duodenal intubation].

Cholesterol crystallization in a necessary step in the formation of cholesterol gallstones. Our purpose was to study the relationship between the presence of biliary cholesterol crystals and radiolucent gallstones. Bile was obtained by duodenal intubation from 60 subjects free of hepatic disease: 40 patients had radiolucent gallstones and in the remaining 20 subjects no gallstones could be found either by oral cholecystography or by ultrasound examination. In each patient a bile sample was used to search for cholesterol crystals; in another sample, biliary cholesterol, phospholipids and bile acids were measured to calculate the lithogenic index. Among the 44 subjects with lithogenic bile, 34 had radiolucent gallstones. Twenty-two out of the 60 patients had both cholesterol crystals and radiolucent gallstones; 21 subjects out of the 22 had lithogenic bile. In patients with frequent biliary colic or subacute pancreatitis without visible gallstones, finding cholesterol crystals in bile might suggest medical or surgical specific treatment.