[Sonographic evaluation of the levator ani muscle in women with stress urinary incontinence]

Abstract

Three-dimensional sonography has been used for about 15 years, not only to examine the female genital organs, but also the lower urinary tract and pelvic floor. Three-dimensional sonography offers more information than traditional two-dimensional sonography allowing for a dynamic representation of the examined structures and observation at any angle necessary. Translabial sonography is the best way of a sonographic examination of the lower urinary tract, because it does not affect the mutual relationship of any parts in the lower pelvic area, contrary to the transrectal or transvaginal probes. In order to establish proper treatment of the urinary incontinence symptoms, not only a functional examination of the lower urinary tract, but also a very accurate assessment of the statics of the female genital organs and pelvic floor need to be performed.

Background: The aim of the study was to rate the area and diameters of the limbs of the levator ani muscle using a three-dimensional (3D) translabial sonography in women with stress urinary incontinence without the female genital tract prolapse.

Material and methods: The study group included 100 patients who were examined with the GE Kretz Voluson 730 (GE, Austria), equipped with 6-9 MHz translabial probe. The first group with stress urinary incontinence consisted of 50 women (mean age 56.22 (+/- 10.43) years) and the second group included 50 women without symptoms (mean age 49.40 (+/- 13.22) years). All cases of urinary stress incontinence in the first group were confirm by means of a urodynamic examination. Women in both groups had similar body weight (kilograms), mean (+/- SD): 26.88 (+/- 2.02) and 26.20 (+/- 4,14), respectively. Menopausal status in both groups was not statistically significant and amounted to 7.21 (+/- 8.71) in the group of women with stress urinary incontinence and 4.70 (+/- 6.32) in the group without symptoms. Mean (+/- SD) number of deliveries was significantly higher in the group of women with stress urinary incontinence than in the control group (2.40 (+/- 1.03) and 1.56 (+/- 1.34), respectively). In all cases 3D coronal view of the pelvic diaphragm was obtained and the area and thickness of limbs of the levator ani muscle were measured. All women had about 200 ml urine in the bladder.

Results: The results are presented as means +/- SD. Mean measurements of this area in both groups were 8.54 +/- 1.62 cm2 and 10.57 +/- 1.29 cm2, respectively. Mean thickness of the limbs in the groups were: 8.72 +/- 0.64mm and 10.85 +/- 0.89mm on the left side and 8.85 +/- 0.67mm and 10.89 +/- 0.87mm on right side, respectively. The differences between both groups in all measurements were statistically significant (p < 0.001).

Conclusions: There are some differences involving measurements of the thickness and the area of the limbs of the levator ani muscle in women with and without stress urinary incontinence and without the genital tract prolapse in both groups. The observed differences could have implications in physiotherapy of the pelvic floor muscles in women without statics abnormalities.