RECTOCELES AND THE RECTOVAGINAL SEPTUM REVISITED

S. Kleeman, C. Westermann, A. Silva, R. Pauls, C. Rooney, M. Karram

Seton Center, Good Samaritan Hospital, Cincinnati, OH

OBJECTIVE:   To histologically evaluate the posterior aspect of the pelvic floor; specifically the relationship between the perineum, posterior vagina, anterior rectum and all other intervening tissue.

MATERIALS AND METHODS:  The perineum, posterior vaginal wall, and upper part of the rectum were removed enbloc from four fresh cadavers without pelvic prolapse.  Length of the specimens ranged from 6-7 cm with a perineal thickness of 2.1 to 3.5 cm.  Seven to 26 serial sections were taken from each specimen starting distally at the perineal body moving proximally to the vaginal apex with at least one sagittal section per specimen.  Sections extended laterally to include the levator muscles.  All sections were stained with H&E, and selected sections from each case were also stained with Masson trichrome and an elastic stain.

RESULTS:  All 4 specimens showed dense connective tissue and no plane of cleavage for 3-3.5 cm proximally from the posterior forchette.  Proximal to this, in all 4 specimens the space between the muscular wall of the vagina and the muscular wall of the rectum was composed of adipose tissue with discontinuous bands of fibrous tissue (or loose areolar tissue).  This appears to be a natural line of cleavage.  Histologically, no well defined evidence of fascia or a rectovaginal septum was identified.

CONCLUSIONS:  Histologically there is no evidence of a distinct fascial layer between the posterior vaginal wall and the anterior wall of the rectum.  There is a dense layer of fused connective tissue that extends approximately 3-4 cm inside the posterior forchette.  The “adventitial layer” of vagina, which has been termed fascia, is composed of adipose tissue and discontinuous bands of fibrous tissue that become thinner in the upper two thirds of the vagina.  Clinically, it is the splitting of the adventitial layer from the overlying vagina that accounts for the “fascial layer” seen surgically.  Defect specific rectocele repairs use the split adventitial layers to support the anterior wall of the rectum.

Key Words: rectocele, rectovaginal septum  

Disclosure - Speakers Bureau: S. Kleeman, Pfizer; M.M. Karram, Ortho-McNeil, Gynecare, Indevis, Watson; Consultant: S. Kleeman, Mentor, AMS, Boston Scientific; M.M. Karram, Gynecare.