Effect of absorbable gelatin sponge in the middle ear: in vitro and in vivo animal model

Abstract

Conclusion: GelitaSpon gelatin sponge (GS) showed faster reabsorption than gelfoam (GF) in vitro, and GS-packed middle ears resulted in a faster hearing recovery and less inflammation than the ears packed with GF soaked in saline. Soaking GF sponges with boric acid (BA) appeared to offset the inflammatory response of saline-soaked GF, making this inflammatory response comparable to that of GS-packed ears. Objective: To describe the reabsorption and inflammatory effects of absorbable gelatin sponge in the middle ear. Methods: For in vitro evaluation, GF and GS were used as disks immersed in saline solution or 3% BA and placed in gel. Images were captured with a microscope and processed using image processing Toolbox. For in vivo tests, 16 female albino Sprague Dawley rats were divided into four groups: bulla opening; GF + 0.9% saline; GF + BA; and GS + 0.9% saline. An anterior approach to the right bulla was used for surgery. Preoperative and postoperative auditory brainstem response thresholds were measured. Results: In vitro, there was marked degradation of GF by day 14, while GS showed complete degradation by the third day. In vivo, hearing recovery occurred by day 21. GF produced a more severe inflammatory response, which could be reduced by treating the GF with BA.

Keywords:

• Absorbable gelatine
• boric acid
• inflammation
• middle ear surgery

Acknowledgment

Dr Francisco Bruni MD and the Pathology Laboratory team at Clinica El Avila, for tissue processing and evaluation and Dr Vet. Manuel Moya at the Medical Faculty Animal House and Instituto Nacional de Higiene Animal House for animal care and procedures.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.