Histological Study of The Healing of Traumatic Tympanic Membrane Perforation After Vivosorb and Epifilm Application.

Abstract

Untreated traumatic tympanic membrane perforations (TMPs) may lead to permanent perforations and hearing loss. There are many materials that have been previously used for repairing the TMPs. The purpose of this study is to evaluate the clinical and histological effects of Vivosorb (Vv) and Epifilm on healing of TMPs in a rat model. The posterior-inferior quadrant of the tympanic membranes (TMs) in right ears of 14 rats was perforated using a 20-g needle and then the animals were randomly divided into 2 equal groups (n = 7). The perforated right TMs were treated with either Vv (Vv group) or Epifilm (Ep group). The left TMs of 7 rats were perforated in same way and allowed to close spontaneously without any topical material applications (spontaneous closure group as sham control, SC). The left tympanic membranes of the other 7 rats were not perforated and used as normal controls (NC group). On postoperative 15th day, tympanic bullas were extracted from killed rats and examined morphometrically and histopathologically. Perforation closure rate was 85.7% (6/7) in both Vv and SC groups. Perforations of Ep group closed in 7/7 (100%) ears. The thicknesses of the perforated membranes were increased in SC and especially Vv groups. Also, connective tissue fibrosis, blood clots, and epithelial degenerations were detected in SC and Vv groups. The mean fibroblastic reaction scores of Vv, Ep, and SC groups were 2.14(+), 0.57(+), and 1.71(+) respectively, on comparison with NC group. The mean neovascularization score was 1.42(+) in Vv group, 0.14(+) in Ep group, and 0.57(+) in SC group. Vivosorb and especially Epifilm can improve the healing process in traumatic TMPs and additionally, Epifilm might be more preferred for the treatment of TMPs because of causing lesser fibrosis.