Etiological study of pelvic organ prolapse and stress urinary incontinence with collagen status and metabolism

Abstract

To explore the alteration of collagen ultrastructure and content in uterine ligaments and paraurethral tissue and explore whether the alteration may contribute to stress urinary incontinence (SUI) and pelvic organ prolapse (POP). The cardinal ligament, uterosacral ligament and paraurethral tissue samples were obtained from 90 subjects undergoing hysterectomy. Collagen ultrastructure was examined with transmission electron microscopy. And collagen content and expression of vasoactive intestinal peptide (VIP) were examined with immunohistochemistry. The smooth muscle fascicles were thinner in the patients of SUI and POP. Arrangement of smooth muscle fascicles was disorderly. Fibroblast was metabolically active. The mean collagen fibril diameters in the SUI and POP groups were larger than that in the control group (P < 0.01). The mean contents of collagen I and III in the SUI and POP groups were lower than that in the control group (P < 0.01). The expression of VIP was lower (P < 0.05). Predominance of collagen degradation during tissue repair may contribute to and promote POP and SUI. The decrease of VIP might be related with nerve damage or degeneration to cause or accelerate the progress of pelvic organ prolapse.