Background and objectivePolylactide film (PLF) is used to prevent postoperative peridural adhesion in spinal surgery. Up until now, the antiadhesive effect of bioresorbable PLF in ear middle surgery has not been reported. The purpose of this study is to evaluate the antiadhesive effect of PLF in guinea pigs serving as a model for middle ear mucosal trauma. Materials and methodsThe animals were divided into two groups: the PLF group and the silastic sheeting group. There were seven guinea pigs (fourteen ears) in both groups. Under aseptic conditions, the middle ear mucosa was abraded using a pick inserted transbullaly. A PLF or silicone sheet was then placed into the guinea pigs’ middle ear cavities. The auditory brainstem responses (ABRs) were assessed preoperatively and at three weeks postoperatively while the animals were under general anesthesia. A histopathological study was performed 3 weeks after the operation. ResultsThe difference between the ABR results before the operation and three weeks postoperatively were not statistically significant. The adhesion formation did not appeared in either group. Prominent fibrous capsule formation and inflammation were observed in the silastic sheeting group, but not in the PLF group. Mild fibrous thickening of regenerated mucosa was observed in the PLF group. ConclusionFrom our results, bioresorbable PLF is nonototoxic and biocompatible with the guinea pig's middle ear cavity by short-term evaluation. Further long-term evaluation study is necessary before clinical application.