Cholelithiasis in Taiwan. Gallstone characteristics, surgical incidence, bile lipid composition, and role of beta-glucuronidase

The nature and occurrence of gallstones in Taiwan and their etiologic factors might not be the same as in Western countries and warranted a systematic investigation. Gallbladder biles and gallstones were obtained at surgery from 100 and 74 patients, respectively. Common duct bile and stones were either drained through an indwelling common duct T-tube or aspirated through a nasobiliary catheter in 108 patients. Gallstones were analyzed for bilirubin, cholesterol, bile acid, calcium, and residue, and biles for bile acid, cholesterol, phospholipid, bilirubin, and beta-glucuronidase. There were four major kinds of gallstones in Taiwan: cholesterol/mixed stones, high-residue black formed pigment stones, low-residue brown formed pigment stones, and muddy pigment stones. The surgical incidence of all types of stones increased steadily during the past four decades. During the past 15 years the relative frequencies for mixed, formed pigment, and muddy pigment stones had been roughly 40, 40, and 20%, respectively, with a further increase in the mixed stones and a decrease in the muddy pigment stones in recent years. Improvement of nutritional status and living standards might contribute to such changes. Cholesterol content in the common duct and gallbladder biles was higher in the mixed stone group than in other groups. Bacterial beta-glucuronidase activity was detected in 53% of patients with muddy pigment stones. Endogenous beta-glucuronidase activity and concentration were also highest in this group, intermediate in the formed pigment and mixed stone group, and lowest in the control. We concluded that hypercholesterobilia was responsible for increasing incidence of mixed stones during the past two decades, while both bacterial and human beta-glucuronidase might contribute to pigment cholelithiasis.