Chemical and physical properties of gall stones in South Australia: implications for dissolution treatment

Of 406 consecutive patients with gall-bladder stones, 387 were treated by cholecystectomy and 19 were treated with chenodeoxycholic acid. The gall stones found in 356 of the 387 patients at operation were analysed chemically for cholesterol and calcium, physically for number, size, and mass, and radiologically before cholecystectomy for stone lucency. Gall stones rich in cholesterol (greater than 80% by weight) were present in 75% of patients, while pigment stones (less than 25% cholesterol) were found in 12% of patients. Out of the 406 gall-stone patients, 77 (19%) had functioning gall bladders which contained radiolucent stones 1.5 cm or less in diameter, thereby fulfilling the criteria which are used by most clinicians in selecting patients for dissolution therapy of cholesterol gall stones. The stones of 61 of these patients were available for chemical analysis and 52 (85%) were rich in cholesterol. Using the more stringent criterion for stone size of 1 cm or less in diameter, only 11% of patients had stones suitable for dissolution treatment. Taking into account other factors such as lack of compliance with treatment, obesity, and calcium salts in gall stones, it appears that no more than 10% of gall-stone patients presenting to a general hospital could be successfully treated with chenodeoxycholic acid.