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Urodynamics and massive vesicoureteral reflux
1Department of Urology, Wilford Hall Medical Center, San Antonio, Texas, USA.
Insights
High-grade vesicoureteral reflux significantly impacts lower urinary tract measurements. Urodynamic studies reveal decreased bladder capacity and compliance when reflux is present, affecting management strategies.
Area of Science:
- Pediatric Urology
- Urodynamics
- Renal Pathophysiology
Background:
- Urodynamic studies are crucial for managing bladder pathologies.
- High-grade vesicoureteral reflux (VUR) complicates pressure and volume measurements by combining upper and lower tract characteristics.
- Understanding the isolated lower tract function is essential for accurate diagnosis and treatment planning.
Purpose of the Study:
- To investigate the influence of high-grade VUR on measured bladder volume and compliance.
- To differentiate the lower urinary tract's storage capacity from the effects of reflux during urodynamic evaluation.
Main Methods:
- Urodynamic evaluation was performed on 18 children with high-grade VUR, both with and without temporary ureteral occlusion.
- Bladder pressure and volume were measured during controlled filling.
- Compliance was calculated as the change in volume over the change in pressure, assessing both initial and terminal phases.
Main Results:
- Ureteral occlusion led to a significant 33% decrease in both initial and terminal bladder compliance.
- Median bladder capacity decreased by 16% with occlusion.
- Older age correlated with a greater decrease in terminal compliance when reflux was occluded.
Conclusions:
- High-grade VUR significantly alters measured lower urinary tract volume and compliance.
- Ureteral occlusion during urodynamics provides a more accurate assessment of intrinsic bladder function.
- These findings underscore the importance of accounting for VUR in urodynamic interpretations.
Purpose:
Urodynamic studies are the key to management and reconstruction of bladder pathology. In the face of high grade vesicoureteral reflux measured pressures and volumes reflect the combined storage characteristics of the upper and lower tracts. We examined the influence of high grade reflux on measured volume and compliance (change in volume/change in pressure).
Materials And Methods:
A total of 18 children with high grade vesicoureteral reflux underwent urodynamic evaluation with and without ureteral occlusion. Occlusion was created in the operative suite using ureteral occlusion balloons. After fluoroscopic confirmation of the absence of reflux bladder pressure was measured during filling at a rate of 12.5 cc per minute. During ureteral occlusion bladder capacity was defined as leakage around the urethral catheter, bladder pressure greater than 40 cm. water or volume exceeding estimated bladder capacity for age, as determined by the formula, bladder capacity in ml. = (age + 2) x 30. The ureteral occlusion balloons were removed and similar measurements were obtained in the presence of reflux. Compliance was calculated for the first and last 50% (initial and terminal compliance, respectively) of bladder capacity.
Results:
Mean initial compliance without and with ureteral occlusion was 19.6 versus 13.2 cm. water (33% decrease). Mean terminal compliance without and with occlusion was 12.9 versus 8.6 cm. water (33% decrease, p < 0.005). Bladder capacity decreased a median of 16%. Underlying bladder pathology was evaluated to determine the patients who would benefit most from ureteral occlusion studies. Patients with neurogenic bladder, posterior urethral valves and primary reflux had similar changes in measured compliance with ureteral occlusion. Patients with poor terminal compliance without occlusion and those with bilateral vesicoureteral reflux had greater changes in compliance with occlusion but these changes were not statistically significant (p < 0.05). Age was indicative of a significant decrease in terminal compliance with ureteral occlusion, since older patients had the greatest change in terminal compliance (p < 0.005).
Conclusions:
High grade vesicoureteral reflux influences measured lower tract volume and compliance.