FP02-5. CROSSLINKED HYDROGELS FOR MIDDLE EAR PACKING

Albert Park, Glenn Prestwich, Lisa Hunter, Adrienne Jackson, Casey HUghes, Lawrence McGill, Xiozheng Shu (University of Utah, USA)

Objective: Develop an ideal supportive packing material for ossiculoplasty, tympanoplasty or other otologic procedures.

Methods and Materials: Several materials were prepared then placed into Hartley guinea pig (Elm Hill) middle ear cavities through a large myringotomy incision: Carbylan- SX (Sentrx Surgical, Inc.), gelfoam, and merogel (Medtronics, Inc.). The contralateral ear underwent a large myringotomy without packing. Pre- and postoperative auditory brainstem response studies (ABR) were performed using an Intelligent Hearing system software. The animals were examined weekly. Two weeks following packing placement, the animals were euthanized, and the temporal bones were harvested. Whole temporal bone section was performed and reviewed by a blinded pathologist for presence of implant material, osteoneogenesis, fibrosis or adhesions and for inflammation surrounding the implant.

Results: All the materials except the merogel were easy to place into the middle ear cavity. The merogel contains woven strands that were difficult to trim into the small sizes needed for placement. The merogel group had a smaller average amount of implant present compared to the other groups at two weeks; three of seven animals had no implant present in the middle ear. The degree of osteoneogenesis was similar among the groups. The merogel and Carbylan groups contained the lowest amount of fibrosis.

Conclusions: This study demonstrates promising results with Carbylan as a potential supportive packing material for otologic procedures. Carbylan compares favorably to merogel and gelfoam in a guinea pig model with respect to ease of placement and amount of fibrosis.

* Contact person email: pcapark@ihc.com