Correlation of ultrasound-estimated bladder weight to urodynamic diagnoses in women with lower urinary tract symptoms.

Objective: To test the hypothesis that the ultrasound-estimated bladder weight (UEBW) will correlate with the urodynamic diagnoses in women with lower urinary tract symptoms, in particular, detrusor underactivity and bladder outflow obstruction. Ultrasonography has been increasingly used in the assessment of lower urinary tract conditions.

Methods: Adult women referred to the urodynamics suite for investigation of lower urinary tract symptoms were enrolled. After urodynamic evaluation, the portable BladderScan BVM 6500 device was used to calculate the bladder wall thickness and UEBW according to a standardized protocol. The patients were categorized according to the urodynamic findings. Women with normal findings, despite the symptoms for which they were referred, were used as the control group. The UEBW and bladder wall thickness measurements were compared between the groups and controls, using the Mann-Whitney and Kolmogorov-Smirnov tests. P <.05 was considered statistically significant.

Results: A total of 187 women were enrolled. The UEBW was significantly lower in the patients with detrusor underactivity than in the controls (39.3 ± 3.0 g vs 45.7 ± 3.1 g, P <.001). Significant differences were also noted between the controls and patients with bladder outflow obstruction, with or without detrusor overactivity (45.7 ± 3.1 g vs 52.1 ± 3.9 g and 52.3 ± 6.2 g, respectively; P <.001 for both). The difference, in terms of the UEBW, between controls and patients with detrusor overactivity was not statistically significant (45.7 ± 3.1 g vs 45.3 ± 3.0, P > .05).

Conclusion: A significantly reduced UEBW in female patients with detrusor underactivity and a significantly increased UEBW in patients with bladder outflow obstruction were found. However, the finding of a significantly increased bladder weight in patients with detrusor overactivity was not confirmed in the present study.