Measurement of cholesterol gallstone growth in vitro

Methods to study growth of gallstones in the laboratory have not been repor ted. We here present such a method. Human cholesterol gallstones were harve sted from patients with multiple nearly identical stones. The gallstones we re washed and added to supersaturated model biles and the formation of chol esterol crystals and the increases in mass of human cholesterol gallstones were studied concurrently, over a period of weeks, using nephelometry and a microbalance, respectively. All stones incubated in model biles supersatur ated with cholesterol increased in mass. Increases in the degree of supersa turation of cholesterol in the model biles resulted in increased growth of stones. The mass increases, the growth rates, and the spatial orientation o f accreted crystalline cholesterol differed among various stone types. The kinetics and structures of stone growth were similar when the stones were i ncubated in supersaturated, native, human gallbladder biles. The structure of accreted cholesterol was the same as found on the surface of some human gallstones that were harvested during apparent active growth in situ. This simple method allows accurate measurements of stone growth in vitro, in pat terns that mimic stone growth in vivo, and is useful for studies on the rel ationships of gallstone growth and the kinetics of cholesterol crystallizat ion.