Does the Immune Reactivity of Bacteria Cause Vaginal Mesh (Polypropylene) Erosion? - A Ultrastructural, Microbiological and Immunohistochemical Analysis.

Aging, birth trauma and extensive pelvic surgery are the causes known to cause advanced pelvic organ prolaspe, fecal as well as urinary incontinence. Surgical treatment is the last resort to manage the above-mentioned clinical manifestations of pelvic floor disorders except the subject is too frail to receive operation.

In order to improve the outcome of reconstructive pelvic surgery, reinforcement with synthetic mesh or biological material is the modern trend in pelvic repair. Unfortunately no prosthesis including synthetic or biological is ideal because vaginal erosion with mesh extrusion which is the subject of this protocol and other complications were reported continuously. As per the literature, the rate for mesh vaginal extrusion ranged between 2.4 and 17% when polypropylene which is the most popular synthetic material used for the mid-urethral sling or pelvic reconstructive surgery to date. The causes of this complication are still controversial which include rejection, poor quality of tissue, surgical artifact, material of mesh and etc.

A prospective controlled study for the investigation of the cause for mesh vaginal erosion was conducted and the results revealed evidences of immune reactivity after mesh implantation, albeit the evidence was not solid (Am J Obstet Gynecol 2004; 191(6): 1868-1874 ). As per the pilot study initially done by us to determine the biofilm-related-infection, we have found bacterial biofilm could adhere to surfaces and interfaces, i.e. bacteria located in the cells just beneath the contacting surfaces in the electron microscopic (EM) analysis. In addition, soon after bacteria infection, proteins in biofilm undergo conformational changes, making them immunogenic and triggers a typical inflammatory response leading to activation of the complement system. Thus, we plan to use CD (clusters of differentiation) antigens - 4, 8, 20, 25, 40, 68 and quantitative analysis of FoxP3 to determine the function of regulatory T cells in the immune response. In addition, bacterial culture and EM analysis of the excised mesh with surrounding vagina tissue will be performed for further analysis of biofilms.