Surgical anatomy of the vaginal vault

Haylen B1, Vu D2

Research Type

Clinical

Abstract Category

Anatomy / Biomechanics

Abstract 356
Open Discussion ePosters
Scientific Open Discussion Session 22
Friday 9th September 2022
13:10 - 13:15 (ePoster Station 6)
Exhibition Hall
Anatomy Female Pelvic Organ Prolapse
1. University of New South Wales, Sydney. Australia, 2. Notre Dame Australia, Sydney. Australia
In-Person
Presenter
B

Bernard Haylen

Links

Poster

Abstract

Hypothesis / aims of study
Vaginal vault (VV) surgery is a key part of curing a majority of pelvic organ prolapse (POP). The surgical anatomy of the vaginal vault has not, however, been subject to extensive examination and description in the literature. This study aims to elucidate and expand current knowledge of the anatomy of the VV and provide detailed images.
Study design, materials and methods
Cadaveric studies were performed on: (i) ten unembalmed cadaveric pelves (observation only); (ii) one unembalmed pelvis (observation, dissection and histology); (iii) five formalin-fixed pelves (dissection). The vaginal vault and its ligamentous attachments were examined. Four tissue blocks (1cm x 2cm) of the ligaments were taken from one unembalmed pelvis starting from its cervical attachments, sampling the ligaments at four  equidistant points  along  its  vertical  extent.
None of the cadaveric studies had undergone hysterectomy. Further confirmation of observations in post-hysterectomy patients were from a separate study on 300 consecutive POP repairs, 46% of whom had undergone prior hysterectomy (1).
Results
(a) Longitudinal aspects: The VV is equivalent to the Level I section of the vagina (Figure IA) - uterine cervix (if present) and/or upper 2.5cm of vagina, measured posteriorly from the top of the posterior vaginal wall (apex or highest part of the vagina) to 2.5cm below this point (2). There are four fornices: anterior, posterior, left and right lateral with the cervix entering the vagina through the anterior fornix. The anterior fornix, pre-hysterectomy is generally lower and shorter than the posterior fornix. The VV posteriorly (2.5cm) is 33% of the Total Vaginal Length (TVL – apex to hymen) and 27% of the Total Posterior Vaginal Length (TPVL - apex to anterior perineum) (1).

b) Axial aspects: The VV pre-hysterectomy, has four fornices (Figure 1B): (i) anterior fornix, through which the cervix protrudes; (ii) posterior fornix, behind the cervix, leading up to the vaginal apex; (iii, iv) two lateral fornices, to the side of the cervix. The apex, the highest point in the vagina, is in the posterior fornix. The VV post-hysterectomy (Figure 1C): (i) anterior fornix with the cuff scar generally visible as a horizontal line, at the lateral ends of which are small depressions (“dimples”) in the vaginal skin; (ii) posterior fornix; (iii,iv) two lateral fornices. The cuff scar line (anterior fornix) is anterior to the vaginal apex (posterior fornix). A traction forcep can be placed around 1cm below the cuff scar line (Figure 1C), around the area of the vaginal apex, to represent readiness for the assessment of VV (specifically apical) prolapse. 

(c) Attachments: The uterosacral ligament (USL) is attached to the posterior aspect of the  cervix and VV.  It spreads to the lateral aspects of the cervix and VV where it becomes confluent with the attachment of the cardinal ligament (CL) to form the cardinal-uterosacral ligament complex (CUSC - Figure 2). CL attachment to the VV is lost at hysterectomy though USL (intermediate segment) attachment is maintained to the VV (beneath the "dimples" at either end of the cuff scar line). Proximal USL attachment is sacral: (i) vertically from the sacrococcygeal joint to S3; (ii) transversely from the pelvic sacral foramina medially to 5cm lateral to the sacro-iliac joint. Sacral (period-like) backache, particularly of an afternoon and after physical activity, is a key symptom of VV prolapse due to tension on the USL.

(d) Surgical implications: Any ligamentous support to the cuff scar at hysterectomy will, in turn, be applied to the anterior fornix, with the posterior fornix not directly involved. The maximal vaginal vault descent generally involves the posterior fornix (apical or posterior VV descent). VV supportive procedures will generally target that area. Posterior vaginal vault descent (PVVD) can be readily measured intraoperatively (1) as a guide to whether a supportive procedure is needed.
Interpretation of results
The VV internally has four fornices (thus “vault”). The anterior fornix, through which the cervix passes is lower and shorter than the posterior fornix. The latter has less support, particularly post-hysterectomy. It would be more vulnerable to prolapse, generally with accompanying anterior (cystocele) and/or posterior (rectocele) vaginal prolapse.
Concluding message
A knowledge of the surgical anatomy of VV anatomy greatly helps the understanding of VV and accompanying vaginal prolapse and its surgical management. We hope we have provided an original outine of that anatomy with a comprehensive description and images.
Figure 1 (A) Oblique view of the vagina and vaginal vault; (B) Axial view of vaginal vault (pre-hysterectomy); (C) Axial view of vaginal vault post-hysterectomy.
Figure 2 Uterosacral and Cardinal ligaments prior to hysterectomy.
References
  1. Int Urogynecol J. 2016,741-745.
  2. Neurourol Urodyn 35(2):137-168.; Int Urogynecol J 27(2):165-194.
Disclosures
Funding None Clinical Trial No Subjects Human Ethics not Req'd Cadaveric Observation Study Helsinki Yes Informed Consent No
14/02/2024 06:56:32