Quantification of major morphological abnormalities of the levator ani

Morphological abnormalities of the levator ani are found in a significant minority of women presenting with symptoms of pelvic floor dysfunction. In this study quantification of such injuries using tomographic three-dimensional (3D) pelvic floor ultrasound was attempted.

In a prospective observational study undertaken at two tertiary urogynecological clinics, 262 consecutive women referred for complaints of lower urinary tract dysfunction and prolapse underwent an interview, clinical assessment and 3D translabial ultrasound imaging. Blinded offline analysis of volume datasets was performed at a later date using 4D View software. Main outcome measures were craniocaudal and ventrodorsal extent of defects of the pubovisceral muscle.

Avulsion injuries were diagnosed in 50 women (19%; 21.3% of the vaginally parous). Defects were found unilaterally (right, n = 17; left, n = 12) and bilaterally (n = 21). In some women they affected the entire volume; in others defects were visible in only two of 16 slices. Hiatal area on Valsalva was correlated weakly with defect score (r = 0.28, P = 0.05) and total defect width (r = 0.4, P = 0.005). Defect score (P = 0.001) and maximum width (P = 0.002) were significantly higher in women who presented with symptoms of prolapse. Defect score was associated with cystocele as assessed clinically (P = 0.021) and on ultrasound (P = 0.014).

Depth and width of levator ani defects can be quantified by tomographic pelvic floor ultrasound. These parameters are associated with the likelihood of symptoms of prolapse and cystocele descent, but not with incontinence.