Numerous methods are presently available for
gallstone dissolution, including oral
bile salts;
cholesterol solvents such as
mono-octanoin and
methyl tert-butyl ether;
calcium or pigment
solvents such as
EDTA and
polysorbate; mechanical extraction techniques through a T-tube tract or after
endoscopic sphincterotomy; or fragmentation methods such as ultrasonography or electrohydraulic
lithotripsy,
lasers, and extracorporeal
shock waves. Which, if any, of these methods will be appropriate for an individual patient depends on the type of stones, whether they are in the gallbladder or bile ducts, whether access to the biliary tree is available, the patient's age and general medical condition, and the availability of expert radiologists, endoscopists, and newer equipment. In the United States, the only available oral
bile salt for
cholesterol gallstone dissolution is
chenodeoxycholate. Ursodeoxycholate, which is more rapid and less toxic, has not been approved by the Federal
Drug Administration. These agents are most effective in thin women with small, floating, radiolucent
cholesterol gallstones in a functioning gallbladder. Only about half of this small subset of patients, however, will experience partial or complete dissolution of stones in 6 to 12 months. Moreover, recurrence is very likely, and the potential toxicity of long-term
therapy is unknown. Thus, for most patients,
cholecystectomy remains the most cost-effective and, perhaps, safest option. Intragallbladder instillation of
methyl tert-butyl ether and
extracorporeal shock wave therapy are also likely to be applicable to only small subsets of patients and to be associated with high recurrence rates. In patients with retained ductal
cholesterol stones and access to the biliary tree,
mono-octanoin therapy is advantageous in that it can be begun as soon as cholangiography demonstrates no extravasation. In properly selected patients, a 90 percent success rate with
mono-octanoin infusion can be expected within a week. Radiologic or endoscopic extraction techniques require maturation of a relatively straight T-tube tract but are not dependent on the type of stone. In the hands of experts, these techniques are highly successful. In postcholecystectomy patients without access to the biliary tree,
endoscopic sphincterotomy has become the preferred method of management and can be expected to succeed in more than 90 percent of patients. At this point, the exact role for ultrasonic or electrohydraulic
lithotripsy and
lasers is unknown. However, these techniques may be applicable in the future in patients with retained bile duct stones in whom extraction and infusion techniques have failed.