Intermittency of cholesterol crystals in duodenal bile from gallstone patients

The detection of cholesterol crystals in duodenal bile is of clinical value in the diagnosis of cholesterol gallstone disease; however, not all patients with cholesterol gallstones have crystals detected in their duodenal bile, thus limiting the value of examination of duodenal bile. The aims of this study were to (i) determine whether the lack of crystals in some patients with cholesterol gallstones was due to (a) the intermittent presence of crystals, (b) spontaneous crystal dissolution, or (c) changes in dietary cholesterol intake; (ii) determine whether incubation of duodenal bile for 24 h would result in crystal formation. Sixteen patients with radiolucent gallstones each underwent three duodenal biliary drainages. Thirty-one percent of patients had crystals in all three bile specimens, 12% in two specimens, 25% in one specimen, and 32% in no specimen. One of 31 specimens with small numbers of crystals initially had no crystals at 24 h, and five specimens initially devoid of crystals developed crystals by 24 h. Despite a significant increase in biliary cholesterol saturation index with increasing cholesterol intake, the prevalence of crystals in bile did not increase in gallstone patients. No crystals were identified in 18 specimens from normal subjects examined initially or in the 15 specimens that were examined after 24 h. We conclude that the intermittent presence of cholesterol crystals in duodenal bile is probably not due to dissolution of crystals or varying dietary cholesterol intake and that the frequency with which crystals are found increases with incubation. Determination of the diagnostic value of multiple duodenal biliary drainages or incubation of bile in patients with normal oral cholecystograms or gallbladder ultrasonograms, however, will require examinations of large numbers of patients.