Active Staphylococcus aureus infection: Is it a contra-indication to the repair of complex hernias with synthetic mesh? A prospective observational study on the outcomes of synthetic mesh replacement, in patients with chronic mesh infection caused by Staphylococcus aureus

Short-term outcomes of a multicentre prospective study using a "visible" polyvinylidene fluoride onlay mesh for the prevention of midline incisional hernia

INTRODUCTION

Prophylactic meshes in high-risk patients prevent incisional hernias, although there are still some concerns about the best layer to place them in, the type of fixation, the mesh material, the significance of the level of contamination, and surgical complications. We aimed to provide answers to these questions and information about how the implanted material behaves based on its visibility under magnetic resonance imaging (MRI).

METHOD

This is a prospective multicentre observational cohort study. Preliminary results from the first 3 months are presented. We included general surgical patients who had at least two risk factors for developing an incisional hernia. Multivariate logistic regression was used. A polyvinylidene fluoride (PVDF) mesh loaded with iron particles was used in an onlay position. MRIs were performed 6 weeks after treatment.

RESULTS

Between July 2016 and June 2022, 185 patients were enrolled in the study. Surgery was emergent in 30.3% of cases, contaminated in 10.7% and dirty in 11.8%. A total of 5.6% of cases had postoperative wound infections, with the requirement of stoma being the only significant risk factor (OR = 7.59, p = 0.03). The formation of a seroma at 6 weeks detected by MRI, was associated with body mass index (OR = 1.13, p = 0.02).

CONCLUSIONS

The prophylactic use of onlay PVDF mesh in midline laparotomies in high-risk patients was safe and effective in the short term, regardless of the type of surgery or the level of contamination. MRI allowed us to detect asymptomatic seromas during the early process of integration.

STUDY REGISTRATION

 This protocol was registered at ClinicalTrials.gov (NCT03105895).

Ventral hernia repair with synthetic mesh in a contaminated field: a systematic review and meta-analysis

PURPOSE

The use of mesh in ventral hernia repair becomes especially challenging when associated with a contaminated field. Permanent synthetic mesh use in this setting is currently debated and this discussion is yet to be resolved clinically or in the literature. We aim to systematically assess postoperative outcomes of non-absorbable synthetic mesh (NASM) used in ventral hernia repair in the setting of contamination.

METHODS

A literature search of PubMed, Embase, Scopus, Cinahl, and Cochrane Library identified all articles from 2000-2020 that examined the use of NASM for ventral hernia repair in a contaminated field. Postoperative outcomes were assessed by means of pooled analysis and meta-analysis. Qualitative analysis was completed for all included studies using a modified Newcastle-Ottawa scale.

RESULTS

Of 630 distinct publications and 104 requiring full review, this study included 17 articles published between 2007 and 2020. Meta-analysis demonstrated absorbable mesh was associated with more HR (OR 1.89, 1.15-3.12, p = 0.008), SSO (OR 1.43, 0.96-2.11, p = 0.087), SSI (OR 2.84, 1.85-4.35, p < 0.001), and unplanned reoperation (OR 1.99, 1.19-3.32, p = 0.009) compared to NASM.

CONCLUSION

The use of NASM for ventral hernia repair in a contaminated field may be a safe alternative to absorbable mesh, as evidenced by lower rates of postoperative complications. This review counters the current clinical paradigm, and additional prospective randomized controlled trials are warranted.

Absorbable Polyglactin vs. Non-Cross-linked Porcine Biological Mesh for the Surgical Treatment of Infected Incisional Hernia

BACKGROUND

The use of absorbable meshes during contaminated or infected incisional hernia (IH) repair is associated with high morbidity and recurrence rates. Biological meshes might be more appropriate but have been described in highly heterogeneous series. This study aimed at comparing the efficacy of absorbable vs. biological meshes for the treatment of contaminated or infected IH in a homogeneous series with a standardized technique.

METHODS

Data of all patients operated on between 2008 and 2015 for contaminated or infected IH, using an absorbable (A) Vicryl® or a biological (B) Strattice® mesh, were reviewed. Patient characteristics, infectious complication rates, and recurrence-free outcome (RFO) were compared between the two groups. A propensity score methodology was applied to a Cox regression model to deal with unbalanced characteristics between groups.

RESULTS

Patient demographics in A (n = 57) and in B (n = 24) were similar except that B patients had larger parietal defects (p < 0.001) and higher Center for Disease Control (CDC) wound class (p = 0.034). Patients in A had statistically significantly more postoperative early (61.4% vs. 33.3%, p = 0.03) and late (31.2% vs. 8.3%, p = 0.046) infectious complications. Six-, 12-, and 36-month RFO rates were 77%, 47%, and 24%, and 96%, 87%, and 82% in A and B, respectively, p < 0.001. Raw multivariable Cox regression analysis found that B (HR = 0.1, 95% CI [0.03-0.34], p < 0.001) was independently associated with prolonged RFO (HR = 0.091, 95% CI [0.045-0.180], p < 0.001).

CONCLUSION

Biological meshes seem to be superior to absorbable meshes in patients with contaminated or infected incisional hernia. These results need to be confirmed by prospective randomized trials.

Usefulness of sonication procedure in mesh infection diagnosis associated with hernia repair

BACKGROUND

The use of prosthetic meshes is a common practice in hernia repair surgery. However, infection can appear as an important complication where antibiotic selection must be directed by the etiology of the infection. In recent years, sonication has appeared as an important tool for the diagnosis of many biomaterial-associated infections. Here, we evaluated our experience with this methodology for the diagnosis of mesh infection.

METHODS

We retrospectively reviewed the microbiological records between 2015 and 2019 looking for sonicated meshes in the microbiology laboratory. All samples were processed according to the sonication protocol described by Esteban J et al. (J Clin Microbiol. 2008 Feb; 46 (2): 488-92).

RESULTS

26 samples were processed during the study period. 21 of them gave a positive result for culture (11 polymicrobial and 10 monomicrobial ones). Staphylococcus aureus and Candida albicans were the commonest monomicrobial isolates (4 cases each). There were five cases of mixed gut microbiota. The median (interquartile range) UFC count was > 100,000 (50,000- > 100,000) CFU/mL.

CONCLUSION

Sonication is a useful technique for the diagnosis of mesh infection.

Chronic mesh infection complicated by an enterocutaneous fistula successfully treated by infected mesh removal and negative pressure wound therapy: A case report

RATIONALE

Tension-free repair of inguinal hernia with prosthetic materials in adults has become a routine surgical procedure. However, serious complications may arise such as mesh displacement, infection, and even enterocutaneous fistula (EF). The management of chronic mesh infection (CMI) complicated by an EF is very challenging. A simple treatment of infected mesh removal and negative pressure wound therapy (NPWT) may cure the patients with EF with CMI.

PATIENT CONCERNS

A 75-year-old male patient underwent tension-free treatment for a bilateral inguinal hernia at a county hospital 10 years ago. Three months before admission, the right groin gradually formed a skin sinus with outflow of fetid thin pus, and it could not heal.

DIAGNOSES

The patient was diagnosed preoperatively with mesh plug adhesion to the intestine, which resulted in low-flow EF combined with CMI.

INTERVENTIONS

The patient received a simple treatment mode consisting of an incision made from the original incision, but the new incision did not penetrate the abdominal cavity; treatment included resection of the fistula, removal of the mesh, repair of the intestine and local tissue, and continuous irrigation of vacuum sealing drainage (VSD) devices for NPWT.

OUTCOMES

The infected mesh was completely removed. Five VSD devices were utilized to treat the EF and wound. The time from intervention to wound healing was 35 days, and follow-up for 6 months revealed no infection and no hernia recurrence in the right groin.

LESSONS

The NPWT is effective in treating CMI concomitant with EF and does not increase the risk of hernia recurrence.

Plasmon-Based Biofilm Inhibition on Surgical Implants

The insertion of an implant in the body of a patient raises the risk of a posterior infection and formation of a biofilm, which can have critical consequences on the patient's health and be associated with a high sanitary cost. While antibacterial agents can be used to prevent the infection, such a strategy is time-limited and causes bacteria resistance. As an alternative to biochemical approaches, we propose here to use light-induced local hyperthermia with plasmonic nanoparticles. This strategy is implemented on surgical meshes, extensively used in the context of hernia repairing, one of the most common general surgeries. Surgical meshes were homogeneously coated with gold nanorods designed to efficiently convert near-infrared light into heat. The modified mesh was exposed to a biofilm of Staphylococcus aureus ( S. aureus) bacteria before being treated with a train of light pulses. We systematically study how the illumination parameters, namely fluence, peak intensity and pulse length, influence the elimination of attached bacteria. Additionally, fluorescence confocal microscopy provides us some insight on the mechanism involved in the degradation of the biofilm. This proof-of-principle study opens a new set of opportunities for the development of novel disinfection approaches combining light and nanotechnology.