Assessing the Efficacy of Tragal Pumping in a Novel Tympanostomy Tube-Rat Model.

Abstract

Objective: Tragal pumping (TP) is a practice of pushing on the tragus to raise pressure within the external auditory canal and is a commonly recommended adjunctive maneuver believed to facilitate the introduction of ototopical medications into the middle ear cavity via a tympanostomy tube. To investigate the efficacy of TP in the penetration of eardrops into the middle ear cavity via tympanostomy tube, we established the novel tympanostomy tube-rat model. We investigated the histology of the middle ear to determine the efficacy in moving fluid into the middle ear.

Study design: Prospective controlled animal study.

Setting: Animal laboratory in a university hospital.

Methods: Ten rats were recruited, and a tympanostomy tube insertion and green dye eardrops into outer ears were performed on bilateral ears. TP was performed only on 1 ear and was not applied on the other ear in each rat. Green dye in a middle ear cavity in hematoxylin and eosin-stained temporal bone sections was evaluated by blinded experts in microscopic anatomy (staining grade) and by using Image J software (staining level). The results of these 2 methods were statistically validated.

Results: The staining grade (P < .001) and the staining level (P < .001) were significantly higher in the ears which we applied TP than in the control ears. The results of 2 methods were significantly and positively correlated (r = .898, P < .001).

Conclusion: Our results showed that the TP accelerate the penetration of eardrops into the middle ear cavity in the tympanostomy tube-rat model.