Does Mid-vaginal Transverse Diameter Predict Outcomes from Native Tissue Repair?

Objectives: Prior research shows that widened genital hiatus and more advanced POP-Q D and Bp points are associated with higher prolapse recurrence rates following native tissue repairs. The purpose of this study is to determine whether preoperative mid-vaginal transverse diameter (TD) predicts postoperative failure from native tissue repair.

Methods: For this retrospective chart review, we evaluated preoperative midvaginal TD and vaginal colpopexy outcomes after surgery in women who have undergone vaginal colpopexy surgery at a tertiary hospital center from 2016 - 2021. Surgical failure was defined as descent of vaginal apex more than one third of total vaginal length, points Ba or Bp extending beyond the hymen, need for repeat prolapse surgery or pessary placement, or subjective symptoms of a bulge. Continuous variables were summarized using means and standard deviations, and categorical variables were summarized using frequencies and percentages. Logistic regression was used to model the association between preoperative vaginal diameter and the outcome variables. Odds ratios, 95% confidence intervals, and p-values were reported.

Results: Demographic summary statistics for the 123 patients with preoperative transverse diameter measurements is presented in Table 1. The summary statistics for the outcome variables are presented in Table 2. There were only 5 patients who had failure defined as Ba > +1 and only 2 patients who had failure defined as Bp > +1. Due to small numbers, neither of these outcomes could be used to estimate the effect of vaginal diameter.
Additionally, there was no statistically significant effect of preoperative vaginal diameter on either subjective bulge, pessary, or repeat prolapse surgery (OR = 1.22, 95% CI [0.82, 1.84], p = 0.324) or on C point > 1/3 TVL (OR = 1.58, 95% CI [0.96, 2.68], p = 0.075). Overall, there was no statistically significant effect of preoperative transverse vaginal diameter on postoperative failure based on at least one of the four subcategories (OR = 1.31, 95% CI [0.90, 1.93], p = 0.157). All odds ratios were greater than one, indicating a non-significant trend of increased odds of failure as preoperative transverse vaginal diameter increases.

Conclusions: There is no statistically significant effect of preoperative TD on postoperative failure defined by 4 commonly used subjective and objective outcome variables; however, a non-statistically significant trend showing increased odds of postoperative failure with larger TD values may suggest a novel POP-Q variable.