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. Studies examining the older cyanoacrylates have demonstrated variable efficacy and toxicity. Octylcyanoacrylate is a new tissue adhesive that has many ideal properties for otologic surgery.

Methods: Thirteen female C-D rats were anesthetized, and preoperative auditory brainstem response (ABR) testing was performed. A left antrotomy was performed, and the incus was removed. In the adhesive group, the incus was dipped in octylcyanoacrylate and interposed between the tympanic membrane and the stapes; no adhesive was used in the control group. At 8 weeks, postoperative ABR was performed, the integrity of the ossicular chain inspected, and histopathologic analysis of the temporal bones performed. Statistical comparison of ABR results was performed with the Mann-Whitney test.

Results: Seven rats were randomized to the adhesive group and six to the control group, of which four survived. There were no histopathologic differences in the temporal bones of the animals other than the presence of mild foreign body reaction around the ossicular chain of the animals in the adhesive group. The ossicular chain was not intact in two of the four controls, whereas the rest were intact at 8 weeks. Postoperative air conduction ABR results (mean dB sound pressure level) (62.5 control versus 34.3 adhesive, p = 0.010) and air-bone gaps (47.5 control versus 18.9 adhesive, p = 0.008) were significantly better in the adhesive group.

Conclusions: This new medical-grade tissue adhesive improves the hearing results of ossicular chain reconstruction, with no apparent histotoxicity in this animal model.