Vaginal angle is a clinical predictor of posterior compartment support loss

Objectives: Pelvic organ prolapse (POP) is a common pelvic floor disorder in the US. The POPQ is the clinical standard for assessing and staging POP; however, it is primarily utilized by urogynecologists. Apical support loss defects are often missed when the POPQ is not performed. We have observed a wide deflection of the POPQ stick with Valsalva in women with POP. The objective of the present study was to determine if vaginal angle is associated with prolapse stage utilizing a simple physical examination measurement. We also explored associations between vaginal angle, compartment of prolapse, and additional clinically important characteristics.

Methods: This was a cross-sectional study of women aged >18 years who presented to our urogynecology clinics and underwent POPQ and vaginal angle measurements in the same visit. Baseline demographic and clinical data were extracted from the medical record. Vaginal angle was measured using a POPQ stick placed in the vaginal apex. The angle of the stick at rest and with Valsalva was measured using a goniometer with attached line level. Change in angle was calculated by subtracting the angle with Valsalva from the resting angle. Reproducibility of angle measurements between examiners was assessed (r = 0.92-0.95, p < 0.0001). A priori, we estimated that 100 participants were needed per stage (0, 1, 2, 3-4) to detect a mean difference in angle of least 2-10 degrees by stage with 80% power.

Results: Data from 477 women were included, yielding 78 with POPQ stage 0 support, 156 with stage 1, 111 with stage 2, and 132 patients with stage 3-4 prolapse. We found that decreasing resting vaginal angle and increasing change in angle was associated with the transition to stage 2 support loss from 0/1 (Table 1) We observed a positive association between vaginal angle (Valsalva and change) and posterior-predominant prolapse (Table 2). Across all stages, both Valsalva and change angles were greatest with posterior-predominant prolapse (p = 0.0045 and 0.0003, respectively). This trend attenuated with adjustment for stage, age, body mass index (BMI), parity, and hysterectomy status. Additionally, patients with obesity (BMI≥30 kg/m²) and those who have had a hysterectomy had the lowest mean resting angles in both adjusted and unadjusted analyses (obesity: p = 0.0012 and 0.0002, respectively; hysterectomy: p < 0.0001 and 0.0002, respectively).

Conclusions: Using a simple clinical measurement, we found that a decrease in resting vaginal angle was associated with transition to stage 2 prolapse and a greater angle change on Valsalva was associated with both stage 2 prolapse and posterior compartment prolapse. In addition, vaginal angle is associated with BMI, and hysterectomy status. Further evaluation is warranted to explore the associations between these and the development of posterior compartment support loss.