The effect of Xylocaine spray on suture material degradation

Objectives: To compare the tensile strength of fast absorbable Polyglactin 910 suture material when impregnated with various agents for local anesthesia and to investigate whether the presence of ethanol in Xylocaine spray could explain a potential reduction in tensile strength after use of Xylocaine spray. Methods: In all, 120 suture samples of Polyglactin 910 were divided into four groups of 30. These four groups were randomly impregnated with isotonic sodium chloride, isotonic sodium chloride plus Xylocaine spray, isotonic sodium chloride plus Xylocaine gel, or isotonic sodium chloride plus ethanol. After impregnation, the sutures were stored in sealed glass tubes in a heating cabinet at 37°C for 72 h. Thereafter, the tensile strength of these 120 samples was assessed by a universal tensile testing machine. The maximal force needed to break the suture material was recorded in newtons (N). Results: Fast absorbable Polyglactin 910 suture material impregnated with Xylocaine spray or ethanol showed weakened tensile strength (mean values 11.40 and 11.86 N, respectively), whereas the specimens impregnated with Xylocaine gel or sodium chloride retained their tensile strength better (mean values 13.81 and 13.28 N, respectively; mean difference between Xylocaine gel and Xylocaine spray −2.41 N, P < 0.001). Conclusion: In this in vitro experiment, ethanol and Xylocaine spray weakened the tensile strength of fast absorbable Polyglactin 910 sutures. Use of Xylocaine spray, which contains ethanol, for local anesthesia might lead to early breakdown of the suture material and wound rupture. The authors suggest caution when using Xylocaine spray in combination with fast absorbable Polyglactin 910 suture.