Impact of High-Intensity Ultrasound on Strength of Surgical Mesh When Treating Biofilm Infections

The use of cavitation-based ultrasound histotripsy to treat infections on surgical mesh has shown great potential. However, any impact of the therapy on the mesh must be assessed before the therapy can be applied in the clinic. The goal of this study was to determine if the cavitation-based therapy would reduce the strength of the mesh thus compromising the functionality of the mesh. First, Staphylococcus aureus biofilms were grown on the surgical mesh samples and exposed to high-intensity ultrasound pulses. For each exposure, the effectiveness of the therapy was confirmed by counting the number of colony forming units (CFUs) on the mesh. Most of the exposed meshes had no CFUs with an average reduction of 5.4-log₁₀ relative to the sham exposures. To quantify the impact of the exposure on mesh strength, the force required to tear the mesh and the maximum mesh expansion before damage were quantified for control, sham, and exposed mesh samples. There was no statistical difference between the exposed and sham/control mesh samples in terms of ultimate tensile strength and corresponding mesh expansion. The only statistical difference was with respect to mesh orientation relative to the applied load. The tensile strength increased by 1.36 N while the expansion was reduced by 1.33 mm between different mesh orientations.