Anatomy of the Support of the Anterior and Posterior Vaginal Walls
To safely perform procedures on the female pelvic floor, it is imperative that the surgeon has a good three-dimensional understanding of the anatomy in this area. This includes a full appreciation of where important blood vessels and nerves travel, as well as of the relationships between various structures used to support pelvic viscera. Figure 52–1 is a cross-sectional view of the pelvis, demonstrating the relationships of various blood vessels to the vagina, pelvic viscera, ureter, and coccygeus–sacrospinous ligament complex. Figure 52–2 demonstrates the support of the anterior vaginal wall viewed through the retropubic space. Note the white area labeled as the inside of the vaginal wall. In a woman with a well-supported anterior vaginal wall, it is attached to the arcus tendineus fascia pelvis (labeled as white line) laterally and the cervix or vaginal cuff proximally. Because many procedures for incontinence and prolapse involve the passing of needles and trocars through the inner thigh, a firm understanding of the anatomy of the structures in this area is necessary. Figure 52–3 reviews this anatomy as it relates to the retropubic space and vagina.
After the lower, middle, and upper thirds of the vagina are viewed, from the gross dissection it is helpful to consider what can be seen when the vagina is dissected for normal plastic operations. Initially, when the posterior vaginal wall is dissected from the anterior wall of the rectum, the vagina and the rectum are densely fused in the lower third of the vagina. This fusion is seen in operations such as perineorrhaphy and posterior colporrhaphy. As the operator attempts to separate the vaginal wall, no clear plane of dissection is evident from the anterior wall of the rectum. This is the case for approximately 3 to 4 cm from the posterior fourchette. Figure 52–4 shows a dissection of the posterior vaginal wall of a cadaver. Here one can see the upper edge of this dense, connective tissue. Above this edge, one enters the middle third of the vagina. At this point, a plane of cleavage is easily created between the vaginal and rectal walls. In Figure 52–4, this is the area marked high rectocele.
When the dissection is extended above the lower third of the vagina, a natural plane of cleavage is easily created and can be dissected bluntly without difficulty to the level of the cul-de-sac (see Fig. 52–4). The layers of the middle third of the vaginal wall, when viewed microscopically, reveal differences between this middle third of the vagina and the lower and upper thirds of the vagina.
The anterior wall of the vagina shows features similar to those of the posterior vaginal wall (Fig. 52–5). The vaginal wall is densely connected to the urethra in the distal third of the vagina. After extension approximately 3 to 4 cm into the vagina, a plane of cleavage or dissection easily allows the vaginal wall to be separated from the wall of the bladder (Fig. 52–6
