EXPERIMENTAL LOCAL BLADDER EDEMA CAUSING URINE REFLUX INTO URETER AND KIDNEY

Area of Science:

• Urology
• Nephrology
• Experimental Medicine

Background:

• Vesicoureteral reflux (VUR) is a significant risk factor for urinary tract infections and kidney damage.
• Understanding the mechanisms of VUR is crucial for developing effective preventative and therapeutic strategies.

Purpose of the Study:

• To investigate the effects of experimental intravesical ureter infiltration on urine reflux in animal models.
• To elucidate the role of ureterovesical valve integrity and intravesical pressure in the development of reflux.
• To explore the potential implications of experimentally induced reflux for human urinary tract health.

Main Methods:

• Induction of reflux via infiltration of magnesium sulfate or saline into the ureter of anesthetized guinea pigs, rabbits, and dogs.
• Measurement of vesical pressures required to induce reflux and assessment of valve competence at varying pressures.
• Histopathological examination of bladder tissue, focusing on ureterovesical valves, to identify inflammatory or structural changes.

Main Results:

• Experimental infiltration induced significant urine reflux in rabbits (81%) and dogs (82%), and to a lesser extent in guinea pigs (33%).
• Low intravesical pressures (2-12 mm Hg) were sufficient to cause reflux, often due to non-obstructive edema of the ureterovesical valves.
• Edematous valves, initially incompetent, could become competent at higher intravesical pressures; spontaneous reflux and valve orifice changes were also observed.

Conclusions:

• Non-obstructive edema of the ureterovesical valves is a primary cause of experimentally induced vesicoureteral reflux.
• The findings in animal models, particularly dogs, are relevant to human physiology due to structural and functional similarities.
• This type of reflux may contribute to the pathogenesis of pyelitis and pyelonephritis in humans.