Gallstone dissolution therapy. Current status and future prospects.

Findings by several groups of investigators have provided a reliable data base that supports a nonoperative approach toward the management of so-called silent gallstones. Considerable progress has been made in the medical dissolution treatment of selected patients with cholesterol gallstones. Ursodeoxycholic acid, and, more recently, a combination of ursodeoxycholic and chenodeoxycholic acids have been shown to be both effective and safe in dissolving gallstones that are predominantly composed of cholesterol. A drawback of the bile acid dissolution therapy lies in a significant recurrence rate after treatment is discontinued. Currently, several new methods of gallstone treatment are under study, which involve either the injection of a cholelitholytic solution, such as methyl tert-butyl ether, into the gallbladder or the use of mechanical means, such as excorporeally induced shock waves, to disintegrate gallstones. These treatments, however, are effective only if the stones are composed mainly of cholesterol without significant admixtures of calcium salts, pigment, or mucus. Most of the treatment failures are probably related to the presence of calcifications that are not visible on conventional radiographs. Future improvements of gallstone dissolution therapy can be expected from the following possible developments: improvement in ability to predict gallstone composition; dissolution of calcium salt-, pigment-, and mucus-containing stones; early treatment, before calcifications occur; combination of chemical and mechanical methods of treatment; stimulation of gallbladder contraction; prevention of stone recurrence after dissolution; and synthesis of new cholelitholytic agents.