Vaginal smooth muscle cell apoptosis is increased in women with pelvic organ prolapse

To compare the smooth muscle content and apoptosis of the vagina in women with and without anterior vaginal wall prolapse. Vaginal tissues were sampled in women with (n = 6) or without (n = 6) anterior vaginal wall prolapse undergoing hysterectomy. Smooth muscle of the vagina was studied by immunohistochemistry. Digital image analysis was used to determine the fractional area of smooth muscle in the histologic cross-sections. Apoptosis was assessed by TUNEL assay. The fractional area of non-vascular smooth muscle in the vagina of women with anterior vaginal wall prolapse was significantly decreased compared to women without prolapse (0.36 ± 0.12 vs. 0.16 ± 0.12 P = 0.021) and the apoptotic index was significantly higher compared to women without prolapse (0.04 ± 0.01 vs. 0.02 ± 0.03, P = 0.041). The fraction of smooth muscle in the vagina is significantly decreased and the rate of apoptosis is higher in women with anterior vaginal wall prolapse compared to women without prolapse.