Middle ear endoscopy and trans-tympanic drug delivery using an interventional sialendoscope: a feasibility study in human cadaveric temporal bones.

OBJECTIVES The aim of our study was to assess feasibility of using a 1.3mm semi-rigid interventional salivary endoscope for middle ear endoscopy and as a route for trans-tympanic delivery of medication in human cadaveric temporal bones. METHODS Five temporal bones harvested from human cadavers were examined. A 1.3mm diameter 0 degree. Marchal interventional sialendoscope equipped with an interventional channel (0.4 mm) and an irrigation/suction channel was used. Middle ear endoscopy was performed via endoscopic guided postero-inferior and antero-superior myringotomies. The round window niche (RWN) was easily identified, and a guide wire was placed within the RWN. Also, the Eustachian tube orifice was identified and cannulated with a guide wire. RESULTS Access to the RWN was obtained via a postero-inferior myringotomy in all five temporal bones (100%). A guide wire could be navigated to the RWN without difficulty in all patients. The opening to the ET was visualized and could be cannulated with a guide wire in all patients where it was attempted (N=3). CONCLUSION The 1.3 mm interventional sialendoscope allowed adequate visualization of the ET, middle ear space, and the RWN with interventional capabilities in a cadaveric model. Our result validates the feasibility of its use for trans-tympanic drug delivery. However, the proposed indication for the use of the sialendoscope needs to be evaluated in a clinical setting. Additional cadaveric and human studies are necessary to further investigate additional applications for its use in the field of otolaryngology.