A Practical Guide to the Nonsurgical Treatment of Gallstones

Summary

Until recently, cholecystectomy was the only treatment available for symptomatic gallstone disease. During the past 20 years, better understanding of the pathogenesis of cholesterol gallstone disease has led to alternative nonsurgical methods for treating gallstones in selected groups of patients.

Use of 2 naturally occurring bile acids, chenodeoxycholic acid (CDCA) and ursodeoxycholic acid (UDCA), was reported in 1972 and 1975, respectively, for successful dissolution of cholesterol gallstones in humans. Both these bile acids act by reducing cholesterol secretion in bile, thus enabling it to solubilise more cholesterol from the stone surface. Micellar solubilisation is involved, together with liquid crystal formation in the case of UDCA. Having been extensively studied in clinical trials to assess efficacy and safety, both these compounds are now available for general use.

The efficacy of CDCA can be enhanced by single bedtime dose administration and by taking a low cholesterol diet. Bedtime administration also enhances the effect of a suboptimal dose of UDCA. CDCA induces dose-related diarrhoea and hypertransaminaemia, and UDCA can induce calcification of gallstones, thus rendering them resistant to medical dissolution. A combination of the 2 bile acids at half the recommended dose for each has become an accepted practice for reducing adverse effects, and this may also enhance efficacy.

One of the main problems of bile acid therapy is that dissolution of gallstones is a very slow process. Use of extracorporeal Shockwave lithotripsy (ESWL) to break the stones into smaller fragments, with concurrent use of bile acids, has been shown to speed dissolution rate and to achieve complete gallstone dissolution in 78% of selected cases within 12 months. Experience in the use of ESWL is limited at this stage and the equipment is not generally available. Another method of achieving quick dissolution of gallstones is direct instillation of liquid ether, methyltert-butyl-ether (MTBE), via a pig-tail catheter inserted percutaneously into the gallbladder cavity.

For any nonsurgical treatment to be effective the stones should be radiolucent and the gallbladder should opacify well on oral cholecystogram. Once treatment with bile acids is discontinued after confirmed gallstone dissolution, bile returns to its original supersaturated state with respect to cholesterol and stones recur in approximately 50% of cases. It is therefore necessary to follow up these patients on a long term basis with regular ultrasound examination in order to detect early recurrence. As no simple method of preventing gallstone recurrence is available at present these patients should be treated with a repeat course of bile acid therapy at the earliest possible time after recurrence.