Ultrasound estimated bladder weight in men attending the uroflowmetry clinic

To determine if measurements of ultrasound estimated bladder weight (UEBW) provide an additional diagnostic tool when assessing men with lower urinary tract symptoms (LUTS) in the uroflowmetry clinic.

One hundred men with LUTS attending the uroflowmetry clinic underwent transabdominal ultrasound measurement of bladder weight, using the BVM 9500 bladder scanner (Verathon Medical, Bothell, WA). These data were explored for any correlation between measurements of maximum flow rate (Q(max)) with UEBW, age, height, weight, body mass index (BMI), ICIQ M-LUTS score, M-LUTS voiding score, M-LUTS incontinence score, IPSS, IPSS quality of life score, voided volume, and post-void residual urine. Based on previously reported probabilities of bladder outlet obstruction (BOO), patients were grouped for analysis (Group 1 = Q(max) <10, Group 2 = Q(max) 10-15, Group 3 = Q(max) >15). A one-way ANOVA was undertaken to assess any difference in mean UEBW between the three groups.

Statistically significant negative correlations between Q(max) and age (r = -0.308, P = 0.002), M-LUTS voiding score (r = -0.298, P = 0.003), IPSS (r = -0.295, P = 0.003), and post-void residual (r = -0.213, P = 0.033) were observed. A statistically significant positive correlation between Q(max) and voided volume (r = 0.503, P < 0.01) was observed. No association between Q(max) and UEBW was observed (r = 0.12, P = 0.243). Mean UEBW for the three groups was remarkably similar. One-way ANOVA identified there was no statistically significant effect of UEBW on Q(max) F(2, 97) = 0.175, P = 0.840.

Mean UEBW did not differ significantly between the three Q(max) groups. Further work is required to investigate the relationship of Q(max) and UEBW in men with urodynamic confirmation of either BOO or detrusor underactivity.