NOVEL ULTRASOUND TECHNIQUES IN THE ASSESSMENT OF FEMALE URETHRA COMPLEX IN THE DIAGNOSIS OF URINARY INCONTINENCE

Purpose: Urinary incontinence in females is becoming an ever-more critical medical and social problem. Traditional routine imaging methods such as transvaginal, transrectal or translabial ultrasound, or MRI with endorectal/endovaginal coil, have a lot of disadvantages. Better assessment of the urethral complex is possible with a novel ultrasound technique: using transvaginal biplane transducers with the ultrasound beam formation perpendicular/parallel to the urethra, and 3D data acquisition.

Aim

The aim of the study was to assess the ultrasound 3D morphology of the urethral complex in nulliparous and multiparous patients.

Methods and Materials: 50 patients were divided into two groups. Twenty nulliparous patients recognised as control group belonged to group 1 (mean age 24 years; range18–35). The group was compared with 30 multiparous patients belonging to group 2 (mean age 52; range 30–72 years) with different degrees of urinary incontinence problems. The examinations were performed with the following B-K Medical (Denmark) equipment:

• A 12–16MHz, rotational 360° transducer with a built-in 3-D acquisition system

• A 9MHz linear transducer with “free-hand“ 3D acquisition

3D ultrasound evaluation included the assessment and subsequent comparison of the following features:

• morphology

• volume of the whole urethral complex with differentiation of rhabdosphincter and non-striated muscles

• urethral lumen and its mucous epithelium

• shape and location of the urethral complex

• distance between bladder neck and lower margin of pubic bones and their behaviour during Valsalva maneuver.

Additionally, angulations between the urethra and posterior bladder wall (beta angle), and angulations between the urethra and vaginal wall (delta angle), were assessed.

Results: There was no statistical significance between the volume of the urethral complex in both groups. But statistically significant differences (p<0,05) were observed among the rhabdosphincter volume (larger in nulliparous patients). Bladder neck distance to the lower margin of pubic bones was smaller in group 2 (incontinent patients), enough to be statistically significant. Statistically significant differences (p<0,001) were observed in the mobility of the urethral complex during Valsalva maneuver, which was higher in group 2. Group 2 patients also showed irregularity of the urethral mucosa and different degrees of calcifications were more often observed. The values of beta angle according to the Mann-Whitney test were significantly smaller in group 1 than in group 2 (median 119° vs. 139°, p<0.001). The values of delta angle according to the same method were significantly greater in group 1 than in group 2 (median 24° vs. 16°, p<0.001).

Conclusions: Novel ultrasound techniques, which have been applied in this study, appear to help in a more detailed assessment of female urethral complex ultrasound morphology. More than any other previously used methods, they improved the understanding of morphology and functionality of the urethral complex in both selected groups.