Hypothesis / aims of study
Vaginal length has been subject to few dedicated articles with significant findings. We wish to examine the total vaginal length  (TVL - vault to hymen posteriorly [Fig 1]) and the total posterior vaginal length [2,3] (TPVL – vault to anterior perineum posteriorly [Fig 1]) in relation to posterior vaginal compartment repairs (PR) in a large series of women, looking for (i) the mean vaginal lengths, (ii) effect of PR and (iii) other factors that might significantly impact those figures.
Study design, materials and methods
At 300 consecutive PRs, mostly following prior or concomitant hysterectomy, the (i) TVL1 (cm) and TPVL2 (cm) were measured pre- and immediately postoperatively. Using linear regression, preoperative measurements were tested for their association with a range of demographic and surgical factors including: age; parity; weight; height; BMI, menopause, prior hysterectomy, POP-Q [1,2] (points C, Ap and Bp, genital hiatus - GH) and PR-Q [2,3] points (perineal gap - PG, posterior vaginal vault descent - PVVD, mid vaginal laxity – MVL undisplaced, rectovaginal fascial laxity - RVFL) posterior prolapse markers. Units used for lengths were mm (calculations and tables); cm ( text and conclusions).
Fig 1: Vaginal levels and lengths illustrating TVL and TPVL
Perioperative: Mean pre-op TPVL was 9.25cm, a mean 1.76cm (23.5%) longer than the mean pre-op TVL of 7.49cm. Post-op TPVL was reduced by a mean 0.17cm (1.8%) to a mean 9.08cm and TVL by a mean 0.08cm (1.1%), to a mean 7.41cm, neither reduction being significant.
Age and menopause: Both TVL and TPVL have a significant inverse relationship to both factors.
Weight, height, BMI (body size): Both TVL and TPVL have a significant positive relationship to weight. The positive relationship to height and BMI was lost on multivariate analysis.
Parity or prior hysterectomy: There was no relationship with TVL or TPVL
Pelvic organ prolapse: TVL/TPVL had significant positive relationships with two PR-Q [2,3] prolapse markers (PVVD, RVFL) suggesting vaginal length may increase with prolapse. Their only relationship with the POP-Q [1,2] markers (Point C) was a surprising inverse one (as Point C should reflect PVVD).
Table: Univariate and multivariate regression models showing relationships between TVL (TPVL essentially the same) and demographic and prolapse markers
Interpretation of results
Both TPVL (mean 9.25cm) /TVL (mean 7.49cm) have minimal change following PR. Both lengths have (i) positive relationships with weight and possibly prolapse (PR-Q prolapse markers [2,3] PVVD and RVFL only) and (ii) inverse relationships with age, menopause and Point C. There appears no relationship with parity and prior hysterectomy.