Urinary Tract Calculi Dissolved by Means of Renacidin

Abstract

Removal urinary tract calculi by surgery may be difficult in patients with poor health or in patients who have been operated on earlier. By means of percutaneous nephrostomy it is possible to irrigate the renal pelvis with Renacidin^® to dissolve calculi. Renacidin is a buffer and mainly consists of citrate and gluconate. The solution makes it possible to dissolve some calculi. This study was carried out in order to evaluate the influence of the concentration of renacidin and of the speed of the irrigation. Urinary tract calculi were obtained from five patients. The calculi were cut into 2 mm thick slices. Each slice was weighed before it was placed in a chamber for irrigation. Irrigation of the slices by means of renacidin was performed at speeds of 30, 60 or 120 ml/h. Slices were also kept in vessels containing renacidin without replacing the fluid during the irrigation. In two series dissolution was investigated for various concentrations of renacidin. Elementary analysis using absorption and spectrophotometric techniques was performed and a qualitative evaluation of the distribution of the inorganic components was carried out using the microradiographic technique. The speed of the dissolution of urinary calculi varied between 0.43 and 7.7 mg/h. Two stones were easily dissolved (5 and 7.7 mg/h) while the three others were more resistant (0.5, 1.0 and 3.0). Diluted renacidin fluid (1 : 3) was less effective and reduced dissolution from 5.8 to 0.7 mg/h. The speed of the irrigation was of minor importance in the experimental situation. The dissolving effect of renacidin varied for different calculi. A higher concentration of the solution was more important than a higher speed of irrigation indicating that the process is mainly dependent on chemical factors. In clinical use the speed of the renacidin irrigation should be high enough to compensate for the dilution caused by the urine output.

Key words:

• calculi
• urinary tract
• treatment
• renacidin