Standard Surgical Approaches to Ear Surgery in Rats

LI Peng; DING Dalian; GAO Kelei; Richard Salvi

doi:10.3969/j.issn.1672-2922.2015.01.003

Abstract：Objective To describe several approaches of ear surgeries for experimental studies in rats. Methods Anes?thetized rats were prepared for demonstration of various ear surgery approaches designed to optimize experimental outcomes in studies with unique goals and exposure requirements. The surgical approaches included the posterior tympanum, superior tym?panum, inferior tympanum and occipital approaches. Results The middle ear cavity and inner ear were successfully exposed from different angles via the mentioned surgical approaches. For example, electrode placement for recording of cochlear bio?electric responses was easily achieved through the posterior tympanum or inferior tympanum approach. Alternatively, drug de?livery or gene transfection via round window membrane was most easily accomplished using the posterior tympanum approach. Cochlear perfusion of protective or ototoxic drugs was best performed using the inferior tympanum approach. Ossicular chain interruption to induce a prolonged conductive hearing loss was readily achieved using a superior tympanum approach. Lastly, surgical destruction of the endolymphatic sac to induce experimental endolymphatic hydrops was readily performed via an oc?cipital surgical approach. Conclusion These standard surgical approaches can be applied in scientific studies of the ear with different purposes covering electrophysiology, conductive hearing loss, intra-cochlear drug perfusion and experimental studies relevant to Meniere’s disease.