espectively). In an uncontrolled clinical trial using 15 mg/kg/day, 70% of the patients with small (less than 15 mm) floatable stones (n = 10) had complete confirmed dissolution.
In the NCGS in patients with nonfloatable stones, chenodiol produced no reduction in biliary pain and showed a tendency to increase the cholecystectomy rate (8% versus 4%). This finding was more pronounced with doses of chenodiol below 10 mg/kg. The subgroup of patients with nonfloatable stones and a history of biliary pain had the highest rates of cholecystectomy and aminotransferase elevations during chenodiol treatment. Except for the NCGS subgroup with pretreatment biliary pain, dose-related aminotransferase elevations and diarrhea have occurred with equal frequency in patients with floatable or nonfloatable stones. In the uncontrolled clinical trial mentioned above, 27% of the patients with nonfloatable stones (n = 59) had complete confirmed dissolutions, including 35% with small (less than 15 mm)(n= 40) and only 11% with large, nonfloatable stones (n= 19).
Of 916 patients enrolled NCGS, 17.6% had stones seen in upright form (horizontal X-ray beam) to float in the dye-laden bile during oral cholecystography using iopanoic acid. Other investigators report similar findings. Floatable stones are not detected by ultrasonography in the absence for dye. Chemical analysis has shown floatable stones to be essentially pure cholesterol).
Other Radiographic and Laboratory Features: Radiolucent stones may have rims or centers of opacity representing calcification. Pigment stones and partially calcified radiolucent stones do not respond to chenodiol. Subtle calcification can sometimes be detected in flat film X-rays, if not obvious in the oral cholecystogram. Among nonfloatable stones, cholesterol stones are more apt than pigment stones to be smooth surfaced, less than 0.5 cm in diameter, and to occur in numbers less than 10. As stone size number and volume increase, the probability of dissolution within 24 months decreases. Hemolytic disorders, chronic alcoholism, biliary cirrhosis and bacterial invasion of the biliary system predispose to pigment gallstone formation. Pigment stones of primary biliary cirrhosis should be suspected in patients with elevated alkaline phosphates, especially if positive anti-mitochondrial antibodies are present. The presence of microscopic cholesterol crystals in aspirated gallbladder bile, and demonstration of cholesterol super saturation by bile lipid analysis increase the likelihood that the stones are cholesterol stones.
PATIENT SELECTION
eva luation of Surgical Risk; Surgery offers the advantage of immediate and permanent stone removal, but carries a fairly high risk. In some patients. About 5% of cholecystectomized patients have residual symptoms or retained common duct stones. The spectrum to surgical risk varies as a function of age and the presence of disease other than cholelithiasis. Selected tabulation of results from the National Halothane Study (JAMA, 1968, 197:775-778) is shown below: the study included 27,600 cholecystectomies.
Low Risk Patients* Cholecystectomy Cholecystectomy & Common Duct Exploration
Women 0-49 yrs 1/1851 1/469
50-69 yrs 1/357 1/99
Men 0-49 yrs 1/981 1/243
50-69 yrs 1/185 1/52
High Risk Patients**
Women 0-49 yrs 1/79 1/21
50-69 yrs 1/56 1/17
Men 0- |
