Chemolysis of calcium oxalate stones: study in vitro and possible clinical application.

The flow cell modeling clinical conditions have been used to study the interaction between dilute chemolytic solutions and large calcium oxalate renal stones. The stone treatment with 5% disodium ethylenediaminetetraacetate aqueous solutions or citrate buffer are found not to provide notable disruption of the samples studied. The significant improvement is reached with the mixed compositions containing both natural and synthetic chelating reagents:citrate and ethylenediaminetetraacetate ions as well as an antibiotic. Description of the chemolytic irrigation, numerical results and their possible clinical application are the main topic of the present research.

The complexon-renal stone interaction: solubility and electronic microscopy studies.

We have studied how complex formation between calcium and ethylenediaminetetraacetate or citrate ions influences the surface texture and the size of passed oxalate-phosphate renal stones. The four hour concrement treatment by sodium citrate or ethylenediaminetetraacetate aqueous solutions strongly affects the stone texture and provides a mass loss of 6-15%. We have found a significant decrease of the calcium and phosphor content on a concrement surface and formation of appreciable cracks. Our results do indicate that the Ca-complexon interaction can be effectively applied for disrupting some types of renal stones and, especially, residual concrements, which frequently occurs after a surgical operation or an extracorporeal shock-wave lithotripsy. This study provides an additional quantitative physicochemical basis for this slightly invasive therapy.