Vaginal mesh insertion for the treatment of pelvic organ prolapse or stress urinary incontinence has been associated with complications including mesh extrusion, exposure, pain, dyspareunia, discharge or generalised remote body symptoms. Pain either vaginal or remote body pain is the most concerning and debilitating complaint. Nine designated specialist Mesh Complication Centres were created to address these presentations and support patients with mesh complications. It remains unclear why some women develop a chronic pain reaction to vaginal mesh, while others do not. We hypothesise that nerve damage or abnormal nerve proliferation into the mesh is associated with the mesh implantation predisposing women to chronic pain.

Objective:
This study explores the relationship between chronic pain presentations in women with vaginal mesh and the presence of abnormal nerve proliferation on the histology specimen following mesh removal. Primary outcome was correlation of clinical with histological data. Secondary outcomes included assessment of other non-pain associated presentations to the mesh clinic.

This was a retrospective observational study of women presenting to the tertiary one stop mesh clinic (OSMC). Local institutional board approval was sought for this service improvement project. Inclusion criteria were women opting for mesh removal surgery between the periods September 2013 and October 2023. Exclusion criteria were women under the age of 18 years, women presenting to the mesh centre without vaginal mesh, and women not opting for mesh removal. All excised mesh was sent for histological examination. 
Associations between different variables are tested with a Spearman’s rank test to obtain a correlation coefficient.

There were 228 mesh removals in the study period. 
Of these, 66% had TVT mesh, 16% had TOT mesh, and 11% had prolapse mesh. 
The main presenting complaints to the OSMC were pain (70%), recurrence of incontinence (41.5%), recurrent UTI (38.3%) and OAB (17.6%). 
To supplement the clinical examination, MRI was used in 51.6% of cases, cystoscopy in 46.5%, UDS in 42.8% and USS in 35.7% of cases. 40.8% required psychological input in their management, with 25.7% specifically reporting a negative effect of the mesh on their psychological wellbeing. 32.7% had onwards referral to the pain team, and 18.2% were managed by physiotherapy. 

173 excised mesh samples were sent for histological analysis. Analysis revealed most of the excised mesh had associated chronic inflammation or fibrosis (chronic inflammation n=70, fibrosis n=55). Only 5 specimens identified nerve proliferation. There was no association between the clinical presentations and the histological results. Specifically, there was no correlation between pain and abnormal nerve proliferation.

Mesh associated complications causes distress. 
Histological examination does not necessarily help in the management of these women. 
The pain presentation is not necessarily due to abnormal nerve proliferation and so other causes of pain need to be investigated .

Through a comprehensive analysis we identified no association between pain presentation and abnormal nerve proliferation in the excised mesh specimens. The reason for the presentation of chronic pain is as yet undetermined from a histological perspective. Further questioning of the data presented ie the role of imaging in determining complications associated with the mesh is warranted. Additional research into the role of chemokines and cytokines in women presenting with pain secondary to vaginal mesh is required.