Can we define excess vaginal space? - Genital hiatus size and prolapse severity are correlated with cube pessary size

Prior studies demonstrated a positive association between increased genital hiatus (GH), advanced prolapse stage and levator ani muscle injury. Moreover wide GH is an established risk factor for recurrent pelvic organ prolapse (POP). Since excess vaginal space is not yet a dimension to estimate in Pelvic Organ Prolapse, we hypothesized that excess vaginal space has a positive correlation with increased GH and could be a new aspect for the assessment of the severity of POP and underlying pelvic muscle damage. We attempted to quantify excess vaginal space by different volumes of different cube pessary sizes.

In a prospective study, 716 symptomatic POP patients without any prior operations were enrolled from January 2011 to December 2017. All patients suffered from stage 2 POP or greater, where either the anterior, middle or posterior compartments or combinations of these were affected. As a conservative self-therapy, space-filling (Dr. Arabin®) cube pessaries were fitted. The size of each was individually adapted for each woman. For data analysis we used Spearman correlation test and Nonparametric statistical test.

All patients included in the study were asymptomatic one week after fitting the pessary. We revealed a positive significant correlation between the genital hiatus (GH) and the size of the cube pessary (ƍ = 0.777,p ≤ 0.001). We also found a positive significant correlation between the size of the cube pessaries and the POP-Q stage. We also managed to find significant differences between cube pessary sizes and corresponding GH values.

Cube pessary sizes may indicate the amount of excess vaginal space. Since excess vaginal space significantly correlates with the increase of the genital hiatus, it could be consider - as well as GH - as a marker for advanced prolapse stage, and a risk factor for the recurrence of pelvic organ prolapse.More studies are needed to identify factors related to excess vaginal space.