Aging of Pelvic Floor in Animal Models: A Sistematic Review of Literature on the Role of the Extracellular Matrix in the Development of Pelvic Floor Prolapse

Abstract

Pelvic organ prolapse (POP) affects many women and contributes significantly to a decrease in their quality of life causing urinary and/or fecal incontinence, sexual dysfunction and dyspareunia. To better understand POP pathophysiology, prevention and treatment, many researchers resorted to evaluating animal models. Regarding this example and because POP affects principally older women, our aim was to provide an overview of literature on the possible biomechanical changes that occur in the vaginas of animal models and their supportive structures as a consequence of aging. Papers published online from 2000 until May 2021 were considered and particular attention was given to articles reporting the effects of aging on the microscopic structure of the vagina and pelvic ligaments in animal models. Most research has been conducted on rodents because their vagina structure is well characterized and similar to those of humans; furthermore, they are cost effective. The main findings concern protein structures of the connective tissue, known as elastin and collagen. We have noticed a significant discordance regarding the quantitative changes in elastin and collagen related to aging, especially because it is difficult to detect them in animal specimens. However, it seems to be clear that aging affects the qualitative properties of elastin and collagen leading to aberrant forms which may affect the elasticity and the resilience of tissues leading to pelvic floor disease. The analysis of histological changes of pelvic floor tissues related to aging underlines how these topics appear to be not fully understood so far and that more research is necessary.

3D Ultrasound in Pelvic Floor: Is It Useful as a Prognostic Tool in Type of Labor Development and Subsequent Pelvic Floor Diseases?

“…Interobserver studies are also advisable in order to compare the agreement between different sonographers. Despite other methods to assess the biomechanical parameters of the pelvic floor muscles have been described, such a biochemical markers like elastin and collagen, ultrasound assessment seems to be the first line of study given its availability, innocuity (no histology is required) and reproducibility [ 57 , 58 ].…”

Perinatal mesenchymal stromal cells of the human decidua restore continence in rats with stress urinary incontinence induced by simulated birth trauma and regulate senescence of fibroblasts from women with stress urinary incontinence

“…A deficiency in this structure would prevent the complete closure of the urethra and could contribute to SUI ( Ashton-Miller and DeLancey, 2007 ), and several studies have shown alterations in the metabolism of collagen and elastin in periurethral connective tissues of patients affected by SUI ( Chen et al, 2006 ; Chen and Yeh, 2011 ). Aging, as well as the hormonal decay of menopause are known causes that lead to changes in the composition and structure of the ECM in the anterior wall of the vagina, resulting in mechanical alterations ( Falconer et al, 1996 ; Lin et al, 2007 ) strongly related to pelvic floor disorders ( Gardella et al, 2022 ). In pregnancy there is an intensive remodeling of the pelvic support structures to allow childbirth, and degenerative processes have been described that affect these structures as a consequence of mechanical stretching and ischemia in vaginal delivery ( Ashton-Miller and Delancey, 2009 ).…”