Gallstones. The present and future of medical dissolution

Solubilization of multilamellar liposomes of egg yolk lecithin by the bile salt sodiumtaurodeoxycholate and the effect of cholesterol--a rapid-ultrafiltration study

The solubilization of multilamellar egg yolk lecithin liposomes by sodiumtaurodeoxycholate in aqueous phase was studied by ultrafiltration as a function of time, bile salt and cholesterol concentration. The corresponding equilibrium states were analysed. Complete solubilization was achieved at total bile salt/lecithin molar mixing ratios of approximately 5. The minimum ratio to start solubilization was 0.1, corresponding to a free bile salt concentration of only 5% of the critical micelle concentration (CMC). Mean equilibrium constants for the partition of bile salts between non-filterable aggregates and filterable mixed micelles and also the free bile salt concentration were determined. Sodiumtaurodeoxycholate had a higher affinity for small mixed micelles than for lamellar mixed aggregates especially in the presence of cholesterol, which reduces the degree and rate of the solubilization process. A non-homogeneous distribution of bile salts in the lipid phase was detected at low bile salt concentrations.

Drug and treatment efficacy of chenodeoxycholic acid in 97 patients with cholelithiasis and increased surgical risk

Patients with symptomatic cholelithiasis who represent higher than normal surgical risks may be the most suitable candidates for medical dissolution of gallstones. Chenodeoxycholic acid was given to 97 patients in a dosage of 15 mg/kg of body weight per day for a period of two years. Complete gallstone dissolution occurred in 27 of 97 patients (28%). If dropouts are excluded then the success rate is 27 of 64 patients (42%). Diarrhea was a common but manageable side effect for most. Thirty-two percent of patients developed chemical liver test abnormality; however, in only 13% was the degree of abnormality sufficient to require temporary (3%) or permanent (10%) cessation of therapy. Although better chemotherapeutic agents are needed, chenodeoxycholic acid is a reasonable choice for patients with non-calcified cholelithiasis in a functioning gallbladder if the patient is a heightened surgical risk. Because of the prolonged treatment period and the possibility of hepatotoxicity this treatment program requires a substantial commitment on the part of both the patient and the physician.

Cholelithiasis and carcinoma of the colon

Cholelithiasis and carcinoma of the colon have similar geographic distributions and common dietary and chemical pathogenetic factors. A study was done to test whether an association between cholelithiasis and colonic cancer existed in the population of Rochester, Minnesota. During the period from 1950-1969, 2413 new cases of cholelithiasis were identified in this population. Because the age- and sex-specific prevalence rates of colorectal cancer in this population were also available, the authors calculated the expected number of cases of colorectal cancer at the time of diagnosis of cholelithiasis. The relative risk (observed/expected) of colonic cancer among persons of all ages and both sexes with cholelithiasis was 1.52 (95% confidence interval, 1.1-2.0). Although the association seems significant, there is a potential bias in that the identification of asymptomatic cases of cholelithiasis might be facilitated in patients who have an operation or frequent follow-up examinations for colonic cancer. When the analysis was repeated separately for symptomatic and asymptomatic cases of cholelithiasis, all the excess (and statistical significance) was confined to the asymptomatic group, and apparent confirmation of the suggested bias. Therefore, the authors believe that no real association exists between cholelithiasis and carcinoma of the colon.

Dissolution of gallstones--when and how?

Availability of bile acid therapy for gallstone dissolution adds another therapeutic choice for treatment of gallstone disease. Because dissolution is slow and eventual outcome uncertain, surgery remains the treatment of choice for most patients who have experienced symptoms clearly related to their gallstones. Patients with only dyspeptic or no gastrointestinal symptoms, especially if significant associated cardiac or pulmonary disease exists, may be candidates for bile acid therapy with chenodeoxycholic acid or its 7-beta epimer, ursodeoxycholic acid, when available. Fifty to 75 per cent of patients, depending on individual criteria, may anticipate complete dissolution. Radiolucent gallstones and gallbladder opacification are basic requirements for cholelitholytic therapy. Periodic assessment of laboratory parameters is necessary at routine visits and when unexpected symptoms occur. In a few patients, evidence of obstructive gallstone disease will develop during bile acid therapy and surgery will be required. The value of bild acid therapy for the relief of dyspeptic symptoms, the role of bile analysis, and optimal long-term therapy remain to be established.