Neurophysiological aspects of electrical pulse stimulation in patients with urolithiasis.

Stimulation of the peristaltic activity of the ureter is a pathogenetically substantiated component of the lithokinetic effect. AIM: The aim of the work was to study the effects of electrical impulse stimulation on ureteral motility in patients with urolithiasis. MATERIALS AND METHODS: 47 patients with urolithiasis, aged 27-59 years, with unilateral ureteral stones, up to 5 mm in size, were studied. The patients underwent translumbar electrical impulse stimulation according to the original method. The results were assessed by the change in the frequency of ureteral emissions and the duration of the interval between two consecutive ureteral emissions. RESULTS: As a result of the method used, there is an increase in the average frequency of ureteral ejections from 1.38±0.49 to 2.20±0.84 minutes (p<0.05), a decrease in the average duration of the interval between two consecutive ureteral ejections from 44.48 ±7 .89 to 27.96±3.89 seconds (p<0.05). The impact was well tolerated by patients. There were no changes in hemodynamic parameters. CONCLUSIONS: Transdermal exposure to single electric stimuli of a rectangular shape has significant effect in patients with urolithiasis as electric pulse stimulation helps to increase the peristaltic activity of the ureter by initiating additional peristaltic waves. To achieve this effect, it is advisable to apply range of 15-30 mA at a time moment corresponding to the last third of the interval between ureteral emissions, when applying stimulating electrodes in the lumbar region, in the area of the projection of the renal pelvis and the proximal ureter.

Structure Types of Kidney Stones and Their Susceptibility to Shock Wave Fragmentation.

BACKGROUND: The modern approach in the treatment of urolithiasis involves the use of non-invasive and minimally invasive techniques based on the stone fragmentation, among which shock wave lithotripsy (SWL) is considered as the first-line treatment for kidney stones < 2 cm and proximal ureter stones. OBJECTIVE: To study the microstructure and mineral composition of kidney stones and to evaluate their influence on the stones' susceptibility to fragmentation by shock waves. METHODS: The microstructure and mineral composition of kidney stone samples obtained from shock wave lithotripsy in 87 patients were studied using crystal optical analysis and infrared spectroscopy. The volume fraction of amorphous and crystalline phases of the stone composition, the quantitative and qualitative composition of mineral components were assessed. The fragmentation features of stones with different microstructure were retrospectively analyzed based on the total number of shock waves required for complete stone fragmentation. RESULTS: Three kidney stone structure types were identified: amorphous-crystalline structure stones predominantly including the amorphous phase (type A); amorphous-crystalline structure stones predominantly including the crystalline phase (type B); fully crystalline structure stones (type C). Significant positive correlation between the total number of shock waves required for complete stone fragmentation and the volume fraction of crystalline phase was found. CONCLUSION: The structure type of kidney stones is determined by the volume ratio between the amorphous and crystalline phases of their composition. The amorphous-crystalline structure stones with the predominant content of the amorphous phase are more sensitive to shock-wave exposure. The increase in the volume fraction of crystalline phase in the stone structure reduces the stone's susceptibility to fragmentation by shock waves.