Effects of resterilization on mechanical properties of polypropylene meshes

Background: The re-use of sterile packaged polypropylene meshes in hernia surgery is not recommended by the manufacturers. However, especially in developing and underdeveloped countries, many surgeons are obliged to re-use the mesh pieces after resterilization because of economic problems. The purpose of this study was to determine the effects of ethylene oxide and autoclave resterilization on the mechanical properties of polypropylene meshes. Methods: Repetitive ethylene oxide gas and autoclave sterilizations were applied to polypropylene meshes (Herniamesh S.r.l., San Mauro, Italy) up to 3 times and the effects on the mechanical properties were examined. Gas resterilizations were applied for 4.5 hours at 55'C, whereas for autoclave resterilizations the specimens were kept at 134 degrees C and 3 atm pressure for 64 minutes. Ethylene oxide gas-sterilized samples were labeled as G. and autoclave-sterilized samples were labeled as A.. Effects of the resterilizations on maximum load (Fmax), elongation at maximum load (Delta L), and energy required for complete failure of the specimen (E) were measured. Results: Fmax in the groups showed no significant differences. Delta L values of groups A2, A3, and G3 were found to be significantly lower in comparison with the control group, whereas differences between the control group and other groups were not statistically significant. E values of A2 and A3 groups were significantly lower than that in the control group (P <.05), whereas the differences between the control group and other groups were not found to be statistically significant. No significant variations were determined between samples sterilized 1, 2, or 3 times in scanning electron microscopy micrographs, however, small irregularities were observed on autoclaved samples. Conclusions: Single use of polypropylene meshes is always recommended because of biocompatibility and infection risks. However, if re-use of the open packages is needed, ethylene oxide sterilization is preferred over autoclave sterilization. If ethylene oxide sterilization is not available then I cycle of resterilization with an autoclave can be used. (c) 2006 Excerpta Medica Inc. All rights reserved.