In vivo analysis of the morphologic characteristics of synthetic mesh to resist MRSA adherence.

BACKGROUND

Synthetic mesh has significantly reduced recurrence rates for ventral hernia repair; however, prosthetic mesh infections remain a significant complication. We hypothesized that unique mesh constructs might alter the ability of various synthetic meshes to clear bacterial contamination. To evaluate this, we studied commercially available synthetic meshes ability to clear a bacterial contamination with methicillin resistant Staphylococcus aureus infection.

METHODS

Two hundred and eighty-three rats underwent hernia repair with one of nine synthetic materials. Control animals were closed, and the remainder was inoculated with either 10(4) or 10(6) methicillin-resistant S. aureus (MRSA). Animals were survived for 30 days without systemic antibiotics. At necropsy, the mesh was harvested and quantitative cultures and bacterial clearance assessed.

RESULTS

All clean repairs remained sterile. Rates of bacterial clearance for 10(4) repairs revealed that unprotected monofilament materials cleared significantly more bacteria than composite meshes and multifilament meshes (p = <0.01 and p = 0.01, respectively). At higher levels of bacterial contamination (10(6)), all materials had a reduction in bacterial clearance, although monofilament materials had higher bacterial clearance compared to composite meshes (p = 0.03).

CONCLUSIONS

Monofilament unprotected polypropylene and polyester mesh can clear a large percentage of MRSA contaminants. Multifilament, composite anti-adhesive barrier meshes, and laminar antimicrobial impregnated mesh are not able to clear bacterial contamination with MRSA. Unique properties of synthetic material should be considered when evaluating a prosthetic for high-risk incisional hernia repair.