Introduction and hypothesis: This study assesses relative contributions of "midline defects" (widening of the vagina) and "paravaginal defects" (separation of the lateral vagina from the pelvic sidewall).
Methods: Ten women with anterior predominant prolapse and ten with normal support underwent pelvic MR imaging. 3-D models of the anterior vaginal wall (AVW) were generated to determine locations of the lateral AVW margin, vaginal width, and apical position.
Results: The lateral AVW margin was farther from its normal position in cases than controls throughout most of the vaginal length, most pronounced midvagina (effect sizes, 2.2-2.8). Vaginal widths differed in the midvagina with an effect size of 1.0. Strong correlations between apical and paravaginal support were evident in mid- and upper vagina (r = 0.77-0.93).
Conclusions: Changes in lateral AVW location were considerably greater than changes in vaginal width in cases vs controls, both in number of sites affected and effect sizes. These "paravaginal defects" are highly correlated with apical descent.