Transvaginal Mesh-Related Complications and the Potential Role of Bacterial Colonization: an Exploratory Observational Study

Study Objective: This study aimed to investigate the potential role of transvaginal mesh bacterial colonization in the development of mesh-related complications (MRCs). Design: An observational and exploratory study. Setting: Tertiary referral center (Amsterdam UMC, location AMC, Amsterdam, The Netherlands). Patiënts: 49 patients indicated for mesh removal and 20 women of whom vaginal tissue was retrieved during prolapse surgery as a reference cohort. Interventions: collection of mesh-tissue complex (patient cohort) or vaginal tissue (reference cohort) Measurements and Main results: Homogenized samples were used for quantitative microbiological culture. Inflammation and fibrosis were semiquantitatively histologically scored; Gram staining and fluorescence in situ hybridization were used to detect bacteria and bacterial biofilms. Of the 49 patients, 44 samples (90%) were culture positive, with a higher diversity of species and more Gram-negative bacteria and polymicrobial cultures in the MRC cohort than the reference cohort, with mostly staphylococci, streptococci, Actinomyces spp., Cutibacterium acnes, and Escherichia coli. Patients with clinical signs of infection or exposure had the highest bacterial counts. Histology demonstrated moderate to severe inflammation in most samples. Gram staining showed bacteria in 57% of culture-positive samples, and in selected samples, fluorescence in situ hybridization illustrated a polymicrobial biofilm. Conclusion: In this study, we observed distinct differences in bacterial numbers and species between patients with MRCs and a reference cohort. Bacteria were observed at the mesh-tissue interface in a biofilm. These results strongly support the potential role of bacterial mesh colonization in the development of MRCs.