Ossicular chain reconstruction using a new tissue adhesive

Hypothesis: A new medical-grade cyanoacrylate tissue adhesive will improve the results of ossicular chain reconstruction in a rat model. Background: An ideal tissue adhesive has long been awaited by otologists, S tudies examining the older cyanoacrylates have demonstrated variable effica cy and toxicity. Octylcyanoacrylate is a new tissue adhesive that has many ideal properties fur otologic surgery. Methods: Thirteen female C-D rats were anesthetized, and preoperative audit ory brainstem response (ABR) testing was performed. A left antrotomy was pe rformed, and the incus was removed. In the adhesive group, the incus was di pped in octylcyanoacrylate and interposed between the tympanic membrane and the stapes; no adhesive was used in the control group. At 8 weeks, postope rative ABR was performed, the integrity of the ossicular chain inspected, a nd histopathologic analysis of the temporal bones performed, Statistical co mparison of ABR results was performed with the Mann-Whitney test. Results: Seven rats were randomized to the adhesive group and six to the co ntrol group, of which four survived. There were no histopathologic differen ces in the temporal bones of the animals other than the presence of mild fo reign body reaction around the ossicular chain of the animals in the adhesi ve group. The ossicular chain was not intact in two of the four controls, w hereas the rest were intact at 8 weeks. Postoperative air conduction ABR re sults (mean dB sound pressure level) (62.5 control versus 34.3 adhesive, p = 0.010) and ail-bone gaps (47.5 control versus 18.9 adhesive, p = 0.008) w ere significantly better in the adhesive group. Conclusions: This new medical-grade tissue adhesive improves the hearing re sults of ossicular chain reconstruction, with no apparent histotoxicity in this animal model.