Surgical anatomy of the vaginal vault

Vaginal vault (VV) surgery should be a key part of surgery for a majority of pelvic organ prolapse (POP). The surgical anatomy of the VV, the upper most part of the vagina, has not been recently subject to a dedicated examination and description.

Cadaver studies were performed in (i) 10 unembalmed cadaveric pelves (observation); (ii) 2 unembalmed cadaveric pelves (dissection); (iii) 5 formalinized hemipelves (dissection). The structural outline and ligamentous supports of the VV were determined. 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.

The VV is equivalent to the Level I section of the vagina, measured posteriorly from the top of the posterior vaginal wall (apex or highest part of the vagina) to 2.5 cm below this point. It comprises the anterior fornix (through which cervix protrudes or is removed at hysterectomy), posterior fornix and two lateral fornices. Before hysterectomy, the posterior aspects of the cervix and upper vagina are supported by the uterosacral (USL) and cardinal ligaments (CL), the distal segments of which fuse together to form a cardinal-uterosacral ligament complex (cardinal utero-sacral complex), around 2-3 cm long. Post---hysterectomy, there is some residual USL support to the anterior fornix but the posterior fornix has no ligamentous support and is thus more vulnerable to prolapse.

Effective management of VV prolapse will need to be part of most POP repairs. Enhanced understanding of the surgical anatomy of the vaginal vault allows more effective planning of those POP surgeries.