The association between levator-urethra gap measurements and symptoms and signs of female pelvic organ prolapse

Objectives: Levator avulsion is associated with pelvic organ prolapse in women. It is diagnosed clinically by a widened gap on palpation between the insertion of the puborectalis muscle on the inferior pubic ramus and the urethra. This gap can can also be assessed on imaging. This study aimed to determine the association between sonographically determined levator-urethral gap (LUG) measurements and symptoms and signs of prolapse. Methods: This is a retrospective study on 450 women seen in a tertiary urogynecological center for symptoms of pelvic floor dysfunction between January 2013 and February 2014. All had a standardized interview, International Continence Society Pelvic Organ Prolapse Quantification assessment and 4-dimensional translabial ultrasound. Post-imaging analysis of archived ultrasound volumes for LUG measurement was undertaken on tomographic slices at the plane of minimal hiatal dimensions and within 5-mm cranial to this plane, bilaterally at an interslice interval of 2.5 mm, blinded against all clinical data. A LUG of 25 mm or greater was considered abnormal. Results: Mean LUG and maximum LUG in individuals were 22.5 mm (SD, 4.6) and 26.4 mm (SD, 6.0), respectively, with at least 1 abnormal LUG in 51% (n=222). An abnormal LUG in all 3 slices involving the plane of minimal hiatal dimensions and with 5 mm cranial o this plane on at least 1 side was fulfilled in 24% (n=103). The LUG measurements were strongly associated with bother, symptoms and signs of prolapse (P < 0.001 to 0.002). This remained significant on multivariate analysis controlling for potential confounding factors. Conclusions: Sonographically determined LUG is strongly associated with symptoms, symptom bother, and pelvic organ prolapse on clinical examination and imaging.