Effects of Absorbable Gelatine Sponge on Middle Ear Mucosa Alone and with Corticosteroids and Antibiotics: An Animal Study

of absorbable gelatine sponge (AGS), and to find out if AGS combined with corticosteroids and/or antibiotics have an influence on these changes. Study design: Animal study Materials and Methods: Thirty-two adult guinea pigs were divided into four groups, with eight ears in each group. In control group, nothing was inserted to middle ear after traumatization of mucosa (group A). In study groups, sponges soaked with physiologic saline (group B), dexamethasone (group C) or dexamethasone and levofloxacin (group D) was inserted to middle ear after mucosal abrasion. Animals were sacrificed at the end of fourth week and fibrosis, inflammation, microscopic residue of AGS and the signs of foreign body reaction in middle ear mucosa were analyzed under light microscopy. Results: No fibrosis was observed in the study group and inflammation was visible in two ears. Sponge residue was seen in two ears in group B, in two ears in group C and in one ear in group D. Signs of inflammation, fibrosis and foreign body reaction was observed in all study groups more or less, and even if the difference between study groups is not statistically significant, all histopathologic changes were slighter in group D. Conclusion: Since we cannot avoid the use of AGS in otologic surgery, we believe soaking sponges with antibiotics and steroids is the best way to reduce its undesirable effects like fibrosis and foreign body reaction.