BACKGROUND/AIMS: The ewe is increasingly being used as an animal model for pelvic floor disorders. The aim was to further characterize changes in the vaginal properties during its entire lifespan. METHODS: Vaginal tissues were collected at different stages of reproductive life (neonatal, prepubescence, nulliparous, primiparous, multiparous, and menopausal; ≥6 ewes/group). Vaginal size, as well as active and passive biomechanics, was measured. Microscopy included thickness of glycogen, epithelium, lamina propria and muscularis thickness, densities of collagen, elastin, smooth muscle, and nerves. RESULTS: Vaginal dimensions increase during adolescence, peak at reproductive levels, and decrease sharply after ovariectomy. One year after first delivery, the distal vagina gets more compliant, yet this is reversed later in life. The thickness of glycogen staining epithelial layers changed with puberty and menopause. The epithelium was markedly thicker after multiple deliveries. The thickness of lamina propria and muscularis increased in puberty and in nulliparous. Semi-quantitative collagen assessment demonstrated a lower collagen and higher elastin content after first and multiple deliveries. CONCLUSION: The changes in the ovine vaginal wall during representative moments of her lifespan parallel those observed in women.

Centre for Surgical Technologies KU Leuven Leuven Belgium

Department of Development and Regeneration KU Leuven Leuven Belgium

Department of Obstetrics and Gynaecology University of Liège Liège Belgium

INEGI Faculdade de Engenharia da Universidade do Porto Porto Portugal

Institute for the Care of Mother and Child 3rd Faculty of Medicine Charles University Prague Czechia

Laboratory of Tumor and Development Biology GIGA Cancer Institute of Pathology University of Liège Liège Belgium

Pelvic Floor Unit University Hospitals KU Leuven Leuven Belgium

References provided by Crossref.org

Animal models for pelvic organ prolapse: systematic review