Posterior vaginal compartment repairs: Where are the main anatomical defects?

Traditionally, it has been believed that posterior vaginal compartment prolapse was largely due to defects in the rectovaginal fascia, with surgical repairs concentrating on addressing this defect. We aimed to determine the relative size of defects at the different vaginal levels (I-III) following a large number of posterior vaginal compartment repairs (PRs) to determine whether this traditional viewpoint is still appropriate.

In a cross-sectional study of 300 consecutive PRs, mostly following prior or concomitant hysterectomy, two sets of markers of posterior compartment prolapse were used to measure anatomical defects at levels I-III: (i) from Pelvic Organ Prolapse Quantification (POP-Q) system points C, Ap, Bp, and genital hiatus (GH), and from Posterior Repair Quantification (PR-Q) perineal gap (PG), posterior vaginal-vault descent (PVVD), midvaginal laxity (MVL)-vault undisplaced, and rectovaginal fascial laxity (RVFL).

The largest defects were found at level I (PVVD: mean 6.0 cm; point C, mean minus 0.9 cm), and level III (PG, mean 2.9 cm; GH, mean 3.7 cm). Level II defects (MVL-vault undisplaced, mean 1.3 cm; RVFL, mean 1.1 cm; points Ap, Bp, both mean 1.0 cm) were relatively small.

This study suggests that the defects found at surgery for posterior vaginal compartment prolapse were more frequent at the vaginal vault (level I) and vaginal introitus (level III) than at midvagina (level II). These findings should have implications for surgical planning.