Mechanical parameters and chemical composition of gallstones in Egyptian population: an approach to assess amenability to nonsurgical treatment

Background
This study aimed to describe the mechanical parameters and chemical composition of gallstones in Egyptian patients having gallstone disease to determine amenability to nonsurgical treatment. These parameters are related to environment, and to date, it is not available for patients living in the Middle East.
Materials and methods
Three hundred gallstone samples from 39 patients living in Egypt and presented for surgical treatment at Cairo University Hospitals and to the private practice of the first author were included in the study. They were indexed into soft, intermediate, and hard. Each was cut, polished, preserved, and stored in saline. Mechanical parameters were studied and then chemically analyzed to determine cholesterol, calcium, and bilirubin content. Trace metals and elements were determined by particle-induced radiographic emission.
Results
Except four, all cases were females (mean age: 45.9 years), having a single stone in 64.1%, and multiple in 35.9%. Stones were hard in 13 patients and soft in 26, with mean specific gravity of 0.86 (0.69–1.67). The percentage share for the three major components was as follows: cholesterol 70.8% (43–88), bilirubin 29.5% (10–66), and calcium 2.27% (0.02–7.5). The mean percentage for other elements was as follows: carbon 76.2, hydrogen 10.49, nitrogen 0.51 and sulphur 1.33. Trace metals − in micrograms − were copper (0.0019), iron (0.0108), potassium (0.015), magnesium (0.023), sodium (0.146), and zinc (0.012).
Conclusion
The patients are good candidates for nonsurgical treatment. In the light of the unique chemical composition of their stones, extracorporeal shockwave lithotripsy is the best. Oral dissolution needs a long time, whereas contact dissolution has no place. Apart from calcium, the concentration of basic elements and metals is of no value for planning treatment.