Comparison of Mechanical Properties of Nasal Cartilage Preserved in Ethanol at 4 °C versus Normal Saline at -18 °C for Rhinoplasty Reuse.

Introduction: This study aimed to compare the mechanical properties of nasal cartilage preserved in ethanol at 4 °C versus normal saline at -18 °C, with the goal of assessing their suitability for reuse in subsequent nasal surgeries. Materials and Methods: Twenty nasal septal cartilage samples from patients who had undergone rhinoplasty were preserved for two months using two different methods. Ten cartilages were stored in alcohol at 4 °C, while the remaining ten were stored in normal saline at -18 °C. Additionally, a control group consisting of ten fresh cartilage samples was included for comparison. The mechanical properties (namely Young's modulus, fracture stress, yield stress, ductility, and tensile strength) were measured using a universal tensile testing machine STM-20 and analyzed to evaluate the effects of the preservation methods. Results: Significant differences were observed between the groups in mean tensile strength, ductility, Young's modulus, and yield stress (P<0.05). However, no significant difference was found in mean fracture stress (P=0.318). The alcohol-preserved group exhibited significantly lower mechanical properties compared to the saline and fresh cartilage groups (P<0.05). No significant differences were detected between the frozen (saline) and fresh cartilage groups (P>0.05). Conclusions: Cartilage stored in normal saline at -18 °C retained its mechanical properties better than cartilage preserved in alcohol at 4 °C. Freezing did not adversely affect the mechanical properties, and the slightly higher values observed in the frozen group suggest that lower temperature may enhance cartilage elasticity.