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

Abstract

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.

Keywords

• eardrop
• intratympanic injection
• middle ear
• tragal pumping
• tympanostomy tube