Autoimmunity and hernia mesh: fact or fiction?

Peripheral blood immunoprofiling in patients with polypropylene mesh implants for hernia repair: a single-center cohort study

PURPOSE

Surgical mesh, often made from polypropylene, is commonly recommended to enhance hernia repair outcomes in adults. Concerns about polypropylene, as a cause of allergy and/or autoimmune disease prompted this study to evaluate immunological parameters in patients with mesh and healthy controls.

METHODOLOGY

A case-control cohort study was conducted at a university hospital. Electronic patient records of hernia repairs using polypropylene mesh (January 2018-April 2022) were analysed. Blood samples from patients and healthy controls were assessed using various methods, including enzyme-linked immunosorbent assay (ELISA), immunofluorescence, immunoblotting, and flow cytometry.

RESULTS

The database search identified 1544 participants. After applying the exclusion criteria 33 patients remained in the polypropylene mesh group. Patients with mesh had lower median IgG3 levels (p = 0.02) and Rheumatoid factor (RF) IgM (p = 0.018) compared to the control group. Although both IgG3 and RF IgM levels were in the normal reference range. In addition, 5 patients in the mesh group tested positive for serum ANCA levels compared to none in the control group (p = 0.053). No other differences in immunoglobulins, autoantibodies, complement, or immune cell subtypes were observed.

CONCLUSION

Patients with polypropylene mesh exhibited median IgG3 and RF IgM serum levels that were within the normal reference range but slightly lower compared to the control group. Among patients with polypropylene mesh, five displayed positive serum ANCA levels without autoimmune-related symptoms. Overall, no definitive signs of autoimmunity caused by polypropylene mesh. A larger, prospective study is warranted to further explore potential immune responses to polypropylene mesh.

The long-term impact of vaginal surgical mesh devices on pain clinic and psychological service referrals, anti-inflammatory testing and pelvic scans in UK primary care: A cohort study with the Clinical Practice Research Datalink

OBJECTIVE

To examine long-term complications in women with stress urinary incontinence (SUI) and pelvic organ prolapse (POP), with and without surgical mesh implants.

DESIGN

Longitudinal open cohort study from 1 April 2006 (or 1 April 2012) to 30 November 2018.

SETTING

The Clinical Practice Research Datalink (CPRD) Gold database, which is linked to Hospital Episodes Statistics (HES) inpatient data, the HES Diagnostic Imaging Dataset (DID), Office for National Statistics mortality data and Index of Multiple Deprivation socio-economic status data.

SAMPLE

Women aged ≥18 years with a diagnostic SUI/POP Read code.

METHODS

Rates are estimated using negative binomial regression.

MAIN OUTCOME MEASURES

Rates of referrals for: psychological and pain services; urinalysis, C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) testing; and pelvic ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI) scans.

RESULTS

A cohort of 220 544 women were eligible for inclusion; 74% (n = 162 687) had SUI, 37% (n = 82 123) had POP and 11% (n = 24 266) had both. Rates of psychological referrals and CT scans were lower in women with SUI mesh surgery, but this was offset by higher rates of CRP testing in women with SUI or POP mesh, MRI scans in women with SUI mesh, and urinalysis testing and referrals to pain clinics for women with POP mesh.

CONCLUSIONS

Our results suggest a higher burden of morbidity in women with SUI/POP mesh surgery, and that these women may require ongoing follow-up in the primary care setting.

Zwitterion mediated anti-protein adsorption on polypropylene mesh to reduce inflammation for efficient hernia repair

The effectiveness of polypropylene (PP) mesh is often compromised by severe inflammation. Engineering anti-inflammatory coatings has significant implications for PP mesh to repair unwanted hernias. Here, we presented a facile strategy to develop an anti-fouling coating consisting of zwitterionic poly(carboxybetaine methacrylate) (PCBMA), which could prohibit protein adsorption to endow PP mesh with anti-inflammatory efficacy. The incorporation of PCBMA coating had little impact on the raw features of PP mesh. While the modified mesh PCBMA-PP possessed noticeable hydrophilicity increase and surface charge reduction. The excellent lubricity and surface stability enabled PCBMA-PP to exhibit superior anti-fouling capacity, thus efficiently inhibiting the adsorption of proteins. In vivo experiments showed that incorporating the PCBMA layer could provide PP meshes with outstanding anti-inflammatory effects and tissue compatibility for repairing hernias.

Are Surgeons Going to Be Left Holding the Bag? Incisional Hernia Repair and Intra-Peritoneal Non-Absorbable Mesh Implant Complications

Ventral incisional hernias are common indications for elective repair and frequently complicated by recurrence. Surgical meshes, which may be synthetic, bio-synthetic, or biological, decrease recurrence and, resultingly, their use has become standard. While most patients are greatly benefited, mesh represents a permanently implanted foreign body. Mesh may be implanted within the intra-peritoneal, preperitoneal, retrorectus, inlay, or onlay anatomic positions. Meshes may be associated with complications that may be early or late and range from minor to severe. Long-term complications with intra-peritoneal synthetic mesh (IPSM) in apposition to the viscera are particularly at risk for adhesions and potential enteric fistula formation. The overall rate of such complications is difficult to appreciate due to poor long-term follow-up data, although it behooves surgeons to understand these risks as they are the ones who implant these devices. All surgeons need to be aware that meshes are commercial devices that are delivered into their operating room without scientific evidence of efficacy or even safety due to the unique regulatory practices that distinguish medical devices from medications. Thus, surgeons must continue to advocate for more stringent oversight and improved scientific evaluation to serve our patients properly and protect the patient-surgeon relationship as the only rationale long-term strategy to avoid ongoing complications.

The foreign body response: emerging cell types and considerations for targeted therapeutics

The foreign body response (FBR) remains a clinical challenge in the field of biomaterials due to its ability to elicit a chronic and sustained immune response. Modulating the immune response to materials is a modern paradigm in tissue engineering to enhance repair while limiting fibrous encapsulation and implant isolation. Though the classical mediators of the FBR are well-characterized, recent studies highlight that our understanding of the cell types that shape the FBR may be incomplete. In this review, we discuss the emerging role of T cells, stromal-immune cell interactions, and senescent cells in the biomaterial response, particularly to synthetic materials. We emphasize future studies that will deepen the field's understanding of these cell types in the FBR, with the goal of identifying therapeutic targets that will improve implant integration. Finally, we briefly review several considerations that may influence our understanding of the FBR in humans, including rodent models, aging, gut microbiota, and sex differences. A better understanding of the heterogeneous host cell response during the FBR can enable the design and development of immunomodulatory materials that favor healing.