An assesment of neurotoxic effects of polylactic acid bioabsorbable adhesion barrier film by applying to middle ear in guinea pigs

An assesment of neurotoxic effects of polylactic acid bioabsorbable adhesion barrier film by applying to middle ear in guinea pigsObjective: In this study we aimed to assess the effect of polylactic acid (PLA) film barrier which has been used for preventing adhesions during wound healing by applicating it in the middle ear of guinea pigs.Material And Method: 21 male albino guinea pigs included in this study. For each guine pig, while one ear forming the PLA group, the other side formed the control group. Under general anesthesia, after the evaluation of thympanic membranes microscopically, by auditory brainstem response (ABR) measurings, the hearing thresholds and wave latencies are recorded.In PLA group the thympanic bulla fenestrated and PLA left in the middle ear cavity. In the control group only thympanic bulla fenestration performed. Both sides closed with bonewax. In postoperative first and sixth months by ABR measurings, hearing thresholds and wave latencies recorded again and in postoperative sixth month the guinea pigs sacrified and temporal bones are taken for histopathologic assessment.Results: There were no statistically differences of hearing threshold results between groups for each preoperative, postoperative first and postoperative sixth month. Although postoperative results for wave latencies found mildly longer than preoperative results, no statistically difference was noted between groups (p>0,05). While there were no differences between the preoperative and first month results for interpeak latency in two groups, sixth month results found longer than preoperative results. The reasons for these prolonged results were thought as surgical technique and trauma caused by the drill. None of wave morphologies were abnormal. In pathological assessment nonspesific changes due to inflammation and also in some cases normal findings were seen.Conclusion: PLA film barrier can be used especially in otologic surgery as used in most areas of surgery. There is not any toxic effect determined. It prevents adhesion formation and it makes surgeon?s work easier.