Effect of endoscopic sphincterotomy on bile lithogenicity in patients withgallbladder in situ

Background and Study Aims: Endoscopic sphincterotomy results in a continuou s flow of bile into the duodenum and consequently leads to an increase in t he frequency of enterohepatic bile acid cycling. Because bile acids are the driving force of biliary secretion, sphincterotomy may affect bile genesis . The present study,vas undertaken to determine the influence of endoscopic sphincterotomy on bile composition. Patients and Methods: The cholesterol saturation index and the bile acid pa ttern were determined in the gallbladder bile of lithiasis patients with (g roup III) or without sphincterotomy (group I), and in the hepatic bile of p atients with gallbladder in situ who were checked at 3 months after the end oscopic procedure (group II). Stones from each patient were examined for ch emical composition and microstructure. Results: All the patients had cholesterol stones. After endoscopic sphincte rotomy the molar percentages of cholesterol in the gallbladder bile of grou p III and in the hepatic bile of group II were significantly lower (-31% an d -46% respectively) than in group I. Similarly, the cholesterol saturation index in the hepatic bile (0.79) and the gallbladder bile (0.86) from pati ents who had undergone sphincterotomy indicated undersaturation whereas bil e from group I was oversaturated (1.25). On the other hand, endoscopic sphi ncterotomy did not modify the hydrophobicity index of the bile acid pool, e ven though deoxycholate content increased. Conclusions: Endoscopic sphincterotomy causes a marked decrease in the lith ogenicity of bile and thus may prevent the risk of recurrence of cholestero l lithiasis.