BILE LITHOGENICITY AND GALLBLADDER EMPTYING IN PATIENTS WITH MICROLITHIASIS - EFFECT OF BILE-ACID THERAPY

Background & Aims: Biliary cholesterol supersaturation, rapid nucleati on of cholesterol, and altered gallbladder motility are prerequisite f or gallstone formation. However, the pathogenesis of microlithiasis is not clear. The aim of this study was tb determine the abnormalities o f gallbladder emptying and bile composition in patients with microlith iasis. Methods: Nucleation time, cholesterol saturation index (CSI), a nd gallbladder emptying were studied in patients with microlithiasis ( n = 10), patients with gallstones (n = 10), and healthy volunteers (n = 10). Bile analysis was repeated in 6 patients with microlithiasis tr eated with ursodeoxycholic acid (UDCA) for 8 weeks. Results: Nucleatio n time was shorter in patients with microlithiasis and those with gall stones than in healthy volunteers (P < 0.0001). Patients with microlit hiasis had longer nucleation time than those with gallstones (P < 0.00 1). There was no difference in cholesterol levels and CSI in gallstone and microlithiasis patients. However, healthy volunteers had lower ch olesterol levels (P < 0.01) and CSI (P < 0.01). Patients with microlit hiasis had prolongation of nucleation time (P < 0.001) and lowering of CSI (P < 0.001) after UDCA therapy. Gallbladder ejection fraction was higher in microlithiasis patients than in gallstone patients (P < 0.0 1) but lower than in healthy volunteers (P < 0.01). Conclusions: Patie nts with microlithiasis have longer nucleation time and better gallbla dder emptying than patients with gallstones. Bile abnormalities can be successfully corrected with UDCA therapy in patients with microlithia sis.