FiberWire vs FiberTape: Comparison of Bacterial Adherence in a Murine Air Pouch Wound Model

Abstract

Background: For high–tensile strength sutures, past research has largely focused on mechanical properties or bacterial adherence across various manufacturers. Purpose: This study investigated high-tensile strength sutures with different shapes but otherwise identical composition. The purpose was to evaluate the differences between high–tensile strength suture wire and suture tape relative to bacterial adherence and bacterial retention after washout. Study Design: Controlled laboratory study. Methods: Sutures were implanted in dorsal air pouches of 72 BALB/cJ mice. Experimental pouches were inoculated with Staphylococcus aureus; no bacteria were used in the control conditions. The mice were randomized into 3 groups: group 1 underwent suture extraction 7 days after implantation; group 2 underwent an irrigation procedure, followed by immediate suture extraction on day 7; and group 3 underwent an irrigation procedure on day 7, with delayed suture extraction on day 14 after implantation. The sutures were evaluated using confocal microscopy; electron microscopy; and spectrophotometry, through which optical density, as measured by the amount of scattered light, is directly correlated with the number of bacteria. Histological assessment was performed on the pouches. Results: Optical density (mean ± SD) was significantly higher for FiberTape sutures than for FiberWire sutures, respectively, at the 2-hour time point for all groups (group 1, 0.0550 ± 0.0081 vs 0.0162 ± 0.006 [ P = .0054]; group 2, 0.0225 ± 0.0049 vs 0.0056 ± 0.0006 [ P = .0045]; group 3, 0.055 ± 0.0222 vs 0.0043 ± 0.0005 [ P = .0103]). Additionally, groups 2 and 3 showed statistically significant results at the 4-hour time points (group 2, 0.0384 ± 0.0087 vs 0.0145 ± 0.0042 [ P = .0280]; group 3, 0.0532 ± 0.0159 vs 0.0101 ± 0.0025 [ P = .0058]). The wash fluid also demonstrated significantly greater optical density for the FiberTape than the FiberWire sutures, respectively, at the 2-hour time point for all groups (group 1, 0.1657 ± 0.0319 vs 0.0317 ± 0.008 [ P = .0063]; group 2, 0.0522 ± 0.0156 vs 0.0127 ± 0.0022 [ P = .0219]; group 3, 0.1707 ± 0.0205 vs 0.0191 ± 0.0053 [ P < .0001]). No bacterial growth occurred in the control conditions. Histological assessment revealed only mild inflammation in the control groups as compared with more severe responses in the experimental groups at all time points. Conclusion: FiberTape was associated with increased bacterial adhesion as well as retention as compared with FiberWire in an in vivo murine wound model. Clinical Relevance: This study demonstrates that suture design influences the occurrence of and ability to clear surgical infection and must be considered when selecting high-tensile strength sutures in a clinical setting.