[Changes of collagen content in uterine ligaments of perimenopausal women with relaxation of pelvic supports].

OBJECTIVE: To investigate the changes in histological characteristics and collagen content in uterosacral and cardinal ligaments of perimenopausal women in relation to relaxation of pelvic supports. METHODS: Twenty-eight subjects undergoing hysterectomies were selected, in which 14 cases were perimenopausal women with relaxation of pelvic support as the relaxation group and 14 women at perimenopausal age with leomyoma, cervical cancer, adenomyosis as the control group. Samples of cardinal ligaments and uterosacral ligaments were obtained at hysterectomies, and the tissues were sliced and stained by Masson's trichrome technique. Histological characteristics of the samples were studied and immunohistochemistry assay was applied to demonstrate the contents of collagen types I and III. RESULTS: (1) The collagen in uterosacral ligaments and cardinal ligaments were stained blue by the Masson's trichome technique. In comparison to the control group, the relaxation group had milder positive stains of the collagen and the stains were distributed in unequal intensities. Collagen content was arranged in loose pattern. Focal arrangement of the collagen was dense but fragmented. Collagen fibers were atrophic. (2) In immunohistochemistry assay and image analysis, collagen was positive in light to deep brown areas. In the relaxation group, positive units of collagen types I and III in cardinal ligaments were 13.8 +/- 2.1 and 9.6 +/- 2.4 respectively. Positive units of collagen types I and III of cardinal ligaments in the control group were 27.4 +/- 3.5 and 17.7 +/- 4.0 respectively. Differences between these two groups were statistically significant (P<0.01). In the relaxation group, positive units of collagen types I and III in utero-sacral ligaments were 15. 8 +/- 2.5 and 10.3 +/- 3.6 respectively. Positive units of collagen types I and III of utero-sacral ligaments of the control group were 29.5 +/- 4.4 and 19.3 +/- 4.6 respectively. Differences between these two groups were statistically significant (P<0.01). CONCLUSIONS: Reductions in collagen types I and III occur in pelvic floor tissue of perimenopausal patients who suffer from pelvic support relaxation. Atrophic and degenerative changes of collagen fibers may be the basic pathological structural alteration in pelvic floor.