Abdominal Wall Reconstruction With PVDF Mesh in the Setting of Active Infection
Condition: Abdominal Wall Defect; Abdominal Wall Hernia; Abdominal Wall Infection; Abdominal Wall Fistula; Infection
MeSH terms: Infections; Communicable Diseases; Hernia; Fistula; Hernia, Abdominal; Hernia, Ventral; Internal Hernia
Study type: Interventional

Summary: 
      The use of synthetic mesh to repair infected defects of the abdominal wall remains
      controversial. This study aimed to evaluate the short-term outcomes of using PVDF mesh to
      treat infected abdominal wall defects in the elective setting.
    

Detailed description: 
      From May 2016 until February 2021, 38 patients presenting with chronic mesh infection and/or
      enteric fistulas were enrolled in this prospective study. The active infection group (AI) was
      compared to a cohort of 38 patients submitted to clean ventral hernia repairs (CC). The
      inclusion criteria in the AI group were the presence of active chronic mesh infection
      (non-healing sinus, exposed mesh, or mesh-related enteric fistulas) resulting from a previous
      repair, or the presence of an enteric/enteroatmospheric fistula, with or without an
      associated abdominal wall defect. The patients invited to participate as controls had a
      primary or recurrent ventral hernia without previous history of infection and were eligible
      for clean operations. The operations in the AI group were classified as Class IV
      (dirty-infected), according to the CDC Wound Classifications, as adopted by the European
      registry for abdominal wall hernias.

      The exclusion criteria were giant ventral hernias, patients on immunosuppressive or
      corticosteroid therapy, patients with portal hypertension, Crohn's disease, acute
      postoperative mesh infection, chronic infections following inguinal hernia repair, and
      emergency operations.

      Demographic data included age, gender, American Society of Anesthesiologists (ASA) score,
      body mass index (BMI), comorbidities, smoking status, cancer history, and the number of
      previous abdominal operations. Perioperative details included the list of associated
      procedures, the defect width, the extension of the pre-aponeurotic dissection, operative
      time, and anesthesia time. Further analysis in the AI group included the clinical
      presentation, the onset of symptoms, the type and position of the infected mesh, the possible
      causes for mesh infection, and the microbiology of mesh explants.

      Patients were followed and operated at the Abdominal Wall and Hernia Repair Unit at the
      Hospital das Clínicas, University of São Paulo, Brazil. Six surgeons of the team conducted
      the operations in both groups. The local ethics committee approved the study. Informed
      consent was obtained from all individual participants. The study was registered at the
      national registry, Plataforma Brasil (https://plataformabrasil.saude.gov.br/login.jsf), CAAE
      52383615.0.0000.0068, and Identifier 1.412.367.

      All the mesh samples used were provided by the manufacturer (FEG Textiltechnik, Aachen,
      Germany) through their local dealer (BMR Medical, www.bmrmedical.com.br), at no cost. None of
      the authors or our institution received any financial support to undertake the study.

      The primary outcomes were the presence of any surgical site occurrences (SSO) or surgical
      site infection (SSI) during the first 30 days after the operation. The secondary outcomes
      included developing hernia recurrence or the recurrence of mesh infection during a 6-month
      follow-up period. An SSI was defined as an infection occurring where the surgery took place
      and was further defined as superficial, deep, and organ space. An SSO was described as any
      surgical infection, wound breakdown, soft tissue ischemia, seroma, and hematoma formation. A
      surgical site occurrence requiring procedural intervention (SSOPI) was described as any wound
      event requiring the opening of the wound, wound debridement, suture excision, percutaneous
      drainage, hematoma evacuation, or mesh removal [14]. The Clavien-Dindo classification [15]
      (Table 2) was applied to all surgical complications. Suspected recurrences of a hernia or
      infection were determined by physical examination and CT scan imaging. Non-surgical
      complications, other operations, and deaths were recorded during the follow-up period.

      The statistical analysis was performed using the computer software Stata: version 16.0 (Stata
      Corp. 2019. Stata: Release 16. Statistical Software. College Station, TX: Stata Corp LLC).
      The frequency distribution was used by means to describe categorical variables (number of
      cases and relative percentage) and for continuous variables, measures of central tendency
      (median and mean) and variability (range and standard deviation). The nonparametric
      Mann-Whitney U test was applied for the statistical evaluation of the association between
      groups and continuous variables. The Student t-test was adopted when data normality was
      identified. Shapiro-Wilk test was applied to verify the normality of data. The association
      between categorical variables in contingency tables was analyzed using the frequency
      Chi-square test and the Fisher exact test adopted in 2x2 tables whenever at least one
      expected frequency was less than five. The 5% significance level was considered for all
      statistical tests.
    

Intervention name(s): Abdominal wall reconstruction
Intervention type(s): Procedure
Intervention description(s): The repair of abdominal wall defects with polyvinylidene (PVDF) mesh
Other intervention name(s): Ventral hernia repair
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Intervention model description: A study group submitted to abdominal wall repair with PVDF mesh in the infected setting compared to a control group submitted to abdominal wall repair with PVDF mesh in the clean setting.
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: ventral hernia; mesh infection; enteric fistula; polyvinylidene mesh; synthetic mesh; abdominal wall reconstruction; complex hernia; DynaMesh