COMPARISON OF POLYDIOXANONE AND SILICONE PLASTIC IN THE PREVENTION OFADHESIVE OTITIS-MEDIA IN THE MONGOLIAN GERBIL

Adhesion of the tympanic membrane to the promontory may occur in chron ic otitis media or in the postoperative ear, Silicone plastic sheets a re commonly used to form a physical barrier to adhesion, These sheets are generally well tolerated, but they are subject to occasional extru sion, encapsulation, or foreign body reaction, The ideal barrier to ad hesion formation would be a nonreactive, flexible, absorbable substanc e that would obviate long-term toxicity considerations. In this study polydioxanone sheets were compared with silicone plastic sheets in the middle ear of the Mongolian gerbil. The eustachian tube was cauterize d to create severe tympanic membrane retraction, A fabricated sheet of polydioxanone was implanted in the middle ear of 30 Mongolian,gerbils and compared with silicone plastic sheets implanted in another group of 30 animals. A sham operation was performed on the other ear to serv e as a surgical control. Evaluation of the temporal bones at 5, 10, an d 15 weeks showed no significant differences in the rate of adhesion f ormation, effusion formation, or polymorphonuclear infiltration by the Fisher exact test. There was histologic evidence that polydioxanone w as still providing an effective barrier at 10 weeks, The results of th is study demonstrate that polydioxanone sheets are as effective and as well tolerated as silicone plastic sheets in an animal model, Further study of polydioxanone in this role is warranted.