Histological assessment of vaginal wall at different stages of pelvic organ prolapse

Collagen is ubiquitous in the human body and it is the main component of connective tissue. Collagen is also the main component of the pelvic supporting structures and Pelvic Organ Prolapse (POP) is the clinical manifestation of a muscular and connective tissue damage. The role of collagen in the physiopathology of POP has been studied with conflicting results, being difficult to distinguish the cause from the effect and to standardize the samples. In this study it has been evaluated the microscopic morphology of the anterior and posterior vaginal wall of patients affected by different stages of POP. Vaginal wall biopsies have been obtained during surgical procedures performed from January 2007 to January 2008. Each biopsy of anterior vaginal wall was provided during cystocele repair as a midline longitudinal full thickness excision including pelvic fascia. Biopsies on posterior compartment were obtained during posterior repair procedures also including a longitudinal midline excision of the vaginal wall and rectovaginal space. Posterior biopsies were further divided according to POP-Q classification system in Ap, Bp, and D point respectively. All samples have been grouped according to the ICS prolapse stadiation. Recurrences or vault prolapses have been ruled out. Microscopic evaluation on Hematossilin & Eosin (H&E) stained sections was performed to quantify inflammatory infiltration and vascularization. Microscopic evaluation on Trichromatic Masson Goldner (TMG) stained sections was performed to assess collagen amount, organization and composition and to assess the muscular component. All parameters were scored semi-quantitatively by two blind observers on two areas of interest. Results show statistically significant difference of collagen amount among different stages of prolapse. Statistically significant differences are also evident in the posterior compartment considering the amount of muscular tissue. Ceresa C is supported by “Fondazione Policlinico di Monza”