The correlation between stress urinary incontinence (SUI) and urethrovesical junction (UVJ) hypermobility has already been established. However, a standard method to assess UVJ mobility is yet to be ascertained. This study aims at comparing the anatomic changes in the UVJ and proximal urethra on perineal ultrasound of women with SUI with a full and empty bladder (with <50 mL of urine).Material and Methods:
This is a prospective cross-sectional study undertaken at the Urinary Incontinence Research Unit of the Universidade Federal de Pernambuco in Recife (Brazil). Forty women with SUI were assessed by perineal ultrasound (7-Mhz probe). The vertical and horizontal distances from the UVJ to the inferior border of the pubic symphysis were recorded both at rest and on strain. Measurements of the proximal urethra length (the distance between the UVJ and the point in the urethra where a horizontal line from the inferior border of the pubic symphysis meets the urethra) were taken both at rest and on strain. Of each parameter, 3 measurements were taken and the mean recorded.Results:
Participants had a mean age of 51.1 ± 10.7 years (range, 31–74 years). Among them, 17.9% reported involuntary urine loss secondary to minor efforts, 23.1% during moderate efforts, and 59% on severe straining conditions. The vertical distance from the UVJ to the inferior border of the pubic symphysis on strain as well as the vertical movement were significantly shorter (P = 0.02 and P = 0.001, respectively) when the bladder was full compared with when the bladder was empty. There was no significant difference in horizontal measurements. The length of the proximal urethra on strain was significantly longer (P = 0.05) and its movement was significantly shorter (P = 0.0001) when the measurements were taken with a full bladder. This is contrary to what was initially thought that with a full bladder, the descent or movements most likely would be more pronounced. Our findings suggest that women with a full bladder trigger other mechanisms to maintain urinary continence or simply they do not push hard enough (fearing leakage) as women with an empty bladder do. Further research monitoring intraabdominal pressure should clarify this issue.Conclusions:
In women with SUI, bladder volume influences vertical UVJ mobility and length of the proximal urethra. However, it is in women with an empty bladder that the ultrasonographic measurements on strain are more pronounced.