Genital hiatus size is associated with and predictive of apical vaginal support loss

Abstract

Background: Recognition and assessment of apical vaginal support defects remains a significant challenge in the evaluation and management of prolapse. There are several reasons that this is likely: (1) Although the Pelvic Organ Prolapse-Quantification examination is the standard prolapse staging system used in the Female Pelvic Medicine and Reconstructive Surgery field for reporting outcomes, this assessment is not used commonly in clinical care outside the subspecialty; (2) no clinically useful and accepted definition of apical support loss exists, and (3) no consensus or guidelines address the degree of apical support loss at which an apical support procedure should be performed routinely.

Objective: The purpose of this study was to identify a simple screening measure for significant loss of apical vaginal support.

Study design: This was an analysis of women with Pelvic Organ Prolapse-Quantification stage 0-IV prolapse. Women with total vaginal length of ≥7 cm were included to define a population with "normal" vaginal length. Univariable and linear regression analyses were used to identify Pelvic Organ Prolapse-Quantification points that were associated with 3 definitions of apical support loss: the International Consultation on Incontinence, the Pelvic Floor Disorders Network revised eCARE, and a Pelvic Organ Prolapse-Quantification point C cut-point developed by Dietz et al. Linear and logistic regression models were created to assess predictors of overall apical support loss according to these definitions. Receiver operator characteristic curves were generated to determine test characteristics of the predictor variables and the areas under the curves were calculated.

Results: Of 469 women, 453 women met the inclusion criterion. The median Pelvic Organ Prolapse-Quantification stage was III, and the median leading edge of prolapse was +2 cm (range, -3 to 12 cm). By stage of prolapse (0-IV), mean genital hiatus size (genital hiatus; mid urethra to posterior fourchette) increased: 2.0 ± 0.5, 3.0 ± 0.5, 4.0 ± 1.0, 5.0 ± 1.0, and 6.5 ± 1.5 cm, respectively (P < .01). Pelvic Organ Prolapse-Quantification points B anterior, B posterior, and genital hiatus had moderate-to-strong associations with overall apical support loss and all definitions of apical support loss. Linear regression models that predict overall apical support loss and logistic regression models predict apical support loss as defined by International Continence Society, eCARE, and the point C; cut-point definitions were fit with points B anterior, B posterior, and genital hiatus; these 3 points explained more than one-half of the model variance. Receiver operator characteristic analysis for all definitions of apical support loss found that genital hiatus >3.75 cm was highly predictive of apical support loss (area under the curve, >0.8 in all models).

Conclusions: Increasing genital hiatus size is associated highly with and predictive of apical vaginal support loss. Specifically, the Pelvic Organ Prolapse-Quantification measurement genital hiatus of ≥3.75 cm is highly predictive of apical support loss by all study definitions. This simple measurement can be used to screen for apical support loss and the need for further evaluation of apical vaginal support before planning a hysterectomy or prolapse surgery.

Keywords: apical support; genital hiatus; prolapse; screening.