[Biometry and assessment of the levator hiatus by three-dimensional pelvic floor ultrasound].

Images of the levator hiatus in 40 nulliparous, 40 asymptomatic parous women and 40 women with pelvic organ prolapse were obtained by transperineal/translabial three-dimentional ultrasonography of the pelvic floor. Volumes were taken at rest and during squeezing. Recontructed images of the levator hiatus at the plane of minimal dimentions were obtained by off-line processing of the stored volumes. The transverse, the longitudinal diameter and the area of the levator hiatus were measured at rest and during squeezing in the three groups. Qualitative assessment of the shape and the symmetry of the levator hiatus at rest was made, too. The average hiatal dimentions (transverse, longitudinal diameter and hiatal area) measured at rest in the three groups were: 35.8 mm, 43.1 mm and 11.84 cm2 in the nulliparous; 43.6 mm, 47.1 mm and 15.1 cm2 in the asymptomatic parous women and 50.5 mm, 57.2 mm and 25.8 cm2 in women with pelvic organ prolapse. Nulliparous women achieved the greatest reduction of hiatal area during squeezing (by 21% average). In asymptomatic parous women the hiatal area reduction averaged 12% while in women with pelvic organ prolapse the average reduction was by 4% only. Levator injury was detected in 7.5% of the asymptomatic parous women and in 22.5% of the women with pelvic organ prolapse. Left-sided injuries predominated. Three-dimentional ultrasound provides easy and high-quality imaging of the pubovisceral miscles for the objective assessment of the levator hiatus in static and dynamic conditions.