Effects of autologous serum on experimental traumatic tympanic membrane perforation

Hypothesis: Autologous serum has positive effects on the healing of acute experimental traumatic perforations of the tympanic membrane. And also autologous serum is one of the treatment options of acute tympanic membrane perforations. Background: The majority of acute perforations of the tympanic membrane heal spontaneously. However, some surgical treatment is needed for persisted perforations. The closure occurs by squamous epithelial migration. Drugs that stimulate this regenerative process may aid in the closure of the perforation, obviating the need for more extensive treatments. There is no previously reported case about effects of autologous serum on perforated tympanic membrane in the literature. This study will be the first one to determine the effects of autologous serum on the healing process of the acutely formed tympanic membrane perforations. Materials and Methods: Based on power analysis of presenting study, we used 20 rats (p1: 0.99 and p2: 0.77 and power: 0.80, Systat 12 for Windows). Twenty rats with bilateral normal tympanic membranes were included in the study by obtaining Institutional Animal Care and Use Committee (IACUC) approval. The posterior quadrant of the tympanic membranes in both ears of the rats was perforated with a 20-gauge needle. Perforations within the left ears of the rats were treated with autotogous serum and the right ears were left untreated as controls. Two weeks later the animals were decapitated and their external ears were separated at the osteocartilaginous junctions bilaterally. 40 surgical specimens (20 right ear and 20 left ear) were fixed in formaldehyde, decalcified in formic acid and then prepared for histological evaluation. The pieces were embedded in paraffin, and the tissue blocks were cut into slides 5 pm thick, treated with hematoxylin and eosin, and examined under light microscopy. The parameters weretympanic membrane thickness, fibroblastic reaction, neovascularization and inflammation Mann-Whitney Test, Chi-Square Tests and student's t-test (SPSS for Win. Ver. 11.5) were used to compare the parameters in the control (right) and treated (left) ears of the rats. Results: There were no significant differences in the histologic parameters, tympanic membrane thickness, fibroblastic reaction, neovascularization and inflammation, between the treated groups and control ears. Conclusion: The study has showed that autologous serum has still some positive effects on healing of tympanic membrane healing even it is not statistically significant. Copyright 2OO5