Biomechanical properties of prolapsed vaginal tissue in pre- and postmenopausal women

Abstract

The aim of this study was to explore the relationship between biomechanical properties and the occurrence of pelvic organ prolapse (POP) through analysis on biomechanical properties of vaginal tissue. The biopsy specimens were obtained from 43 patients undergoing transvaginal hysterectomy, who were assigned into premenopausal POP, postmenopausal POP, premenopausal control and postmenopausal control groups. Tissue specimens were biomechanically assessed by a purpose-built tissue puller system, and stress-strain curves were digitally recorded. The Young's modulus, Poisson's ratio, maximum elongation, maximum fracture of vaginal tissue were 9.45 +/- 0.70, 0.43 +/- 0.01, 1.50 +/- 0.02, 0.60 +/- 0.02 in premenopausal POP group; 12.10 +/- 1.10, 0.39 +/- 0.01, 1.14 +/- 0.05, 0.27 +/- 0.03 in postmenopausal POP group; 6.65 +/- 1.48, 0.46 +/- 0.01, 1.68 +/- 0.11, 0.79 +/- 0.05 in premenopausal control group and 10.26 +/- 1.10, 0.42 +/- 0.01, 1.37 +/- 0.04, 0.42 +/- 0.03 in postmenopausal control group. There was significant difference in biomechanical properties between premenopausal POP group and premenopausal control group (p < 0.01). There was significant difference in biomechanical properties between postmenopausal POP group and postmenopausal control group (p < 0.01). Biomechanical properties in POP group were significantly lower than that in control group, suggesting that degeneration of biomechanical properties in pelvic support construction might lead to the occurrence of POP.

Recent studies of genetic dysfunction in pelvic organ prolapse: The role of collagen defects

“…Previous biomechanical study has also demonstrated that women with prolapse have stiffer vaginal tissues. 38 In contrast, Moalli et al, 31 found increased collagen III in the subepithelial layers of the vaginal wall. These inconsistencies may arise from the following: (i) different methods used to assess collagen quality; and (ii) different biopsy sites from which the collagen samples were obtained.…”

Biomechanical properties of the vaginal wall: effect of pregnancy, elastic fiber deficiency, and pelvic organ prolapse

“…Tissues from women without prolapse were not tested (14). Lei, et al described significant differences between pre-and postmenopausal women with and without prolapse; in general, prolapse conferred less elasticity and greater stiffness although vaginal tissues from women with severe prolapse exhibited low forces at failure (15). A third study showed marked variability in maximal strength and strain with no discernable trends in biomechanical properties of vaginal samples taken from 16 postmenopausal women with prolapse (16).…”

Frequency of Different Stages of Pelvic Organ Prolapse and Factors Leading to it

“…Precise etiology of uterovaginal prolapse is not known but likely to be multifactorial. The severity of prolapse may vary with different risk factors [8][9][10].…”