Analysis Of High Risk Factors For Mesh Exposure And Microscopic Observation After Tansvaginal Reconstructive Pelvic Surgery With Mesh

Objective: To explore the risk factors for the occurrence of Polypropylene Meshexposure after transvaginal reconstructive pelvic surgery (RPS) and to study thehistopathological change in order to find out the mesh related factors.Methods: One hudred and ninty-five patients with sever POP were analized fortheir PP mesh exposure from Jan2004to Dec2012in the First Affiliated Hospital toChinese PLA General Hospital. Clinical data were collected, including patient’s age,severity and site of the POP, menopause status, body mass index (BMI), medicalproblems, gravidity and parity, transvaginal RPS type, concomitant procedures,operation time, blood loss and postoperative morbidity. Mesh exposure was definedthrough vaginal examination. The size, time and site of exposed mesh were codedaccording to standered of ICS. Statistical analysis was performed to analyze thedifferent factors between mesh exposed group and non-exposed group. The exposedmeshes were collected for electronic and optical microscopic observation to identify thehistopathological features.Results: One hudred and ninty-five patients with sever POP were analyzed. PPmeshes were transvaginally placed in the total of209cases, among which anterior wallwere194cases and posterior wall were15cases.The concomintant TVT were61cases.The mean follow-up time was35.08±23.57months.In the period of Jan2004toDec2009,48cases of transvaginal RPS were performed and mesh exposure occurred in7patients (14.6%), while in the period of Jan2010to Dec2012mesh exposure wasfound in25patients out of147cases (17%). The total exposure of PP Mesh was33cases (15.8%).And only1case (1.6%) mesh exposure was found after TVT and TVT-O.Mesh exposure was caculated according to site,anterior and posterior wall were31(15.9%，31/194) and2（13.3%，2/15） cases, respectively. Except that1mesh exposed into the bladder,the rest were confined to vagnial mucosa.The size of mesh exposurewas less than1cm in30cases and more than1cm in3cases. Mesh exposure occurredat1-24months after surgery, among which72.7%of the exposure was occured in thefirst half year after operation. Significant difference was found in operation time andconcomintate procedures between mesh exposure and non exposure groups (P<0.05),Binary Logistic Regression found that concominate procedures number and oprationtime were the risk factors for mesh exposure (P<0.05). Only2cases had recurrentanterior wall prolapse.The overall objective success rate was98.9%.Microscopicobservation found that there were acute inflammation reaction in PP mesh fibers aftermesh implantation (within2months after operation), chronic inflammation reaction(within2-6months after operation) and squamous metaplasia (more than6months).Scanning electron microsope observed that PP mesh fibers were intact within6monthswith connective tissues encapsulation and occasional superfaced cracks. However, after6months, obvious transverse cracks (20-50μm) were found on the surface of the fibers.Conclusions:1. The exposure rate of polypropylene mesh after PRS was15.8%in our study.2. The most of the exposed mesh (96.9%) was less than1cm in size. Except that1mesh exposed into the bladder, the rest were confined to vagnial mucosa.The symptomof vagnial exposure was minimal,which did not affect the outcome of surgery.3. Operation time and concomintant procedures are the risk factors for meshexposure. The more concomintant procedures,the longer operation time, the higer rateof exposure.4. After transvaginal mesh, acute inflammation reaction and chronic inflammationreaction will occur within2months and2-6months,respectively. After6months,squamous metaplasia will occur.5. Six months after transvaginal mesh, fiber degradation will occur, which showsas surface transverse cracks. The reasons for that are still not clear.