[The chemical composition of gallstones and their suitability for litholysis and lithotripsy].

The chemical composition of gallstones removed at surgery from 107 patients (81 women, 26 men; mean age 59 [18-85] years) was examined. In 64 women (79%) and 21 men (81%) microchemical analysis demonstrated concrements with a more than 50% cholesterol content (500 mg/g). Using as definition of cholesterol stones a 75% cholesterol content, only 35 women (43%) and 10 men (39%) would be classified as cholesterol stone carriers. Grossly visible layer formation was present in 18 stones; in eight stones calcium content was higher in the outer layer than in the core. There was no demonstrable relationship between gallstone composition and age.