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

OBJECTIVE: This study aimed to assess the feasibility of using a 1.3 mm, semi-rigid, interventional salivary endoscope for middle-ear endoscopy, and as a trans-tympanic route for delivery of medication, in human cadaveric temporal bones. STUDY
DESIGN: Human cadaveric study.
METHODS: Five temporal bones harvested from human cadavers were examined. A 1.3 mm, interventional sialendoscope was used to make endoscopy-assisted myringotomy incisions in the postero-inferior quadrant (n = 5) and the antero-inferior quadrant (n = 3).
RESULTS: Middle-ear examination was successful in all specimens (n = 5). Access to the round window niche and adequate visualisation of the round window were achieved in all five temporal bones (100 per cent). A guide wire could be navigated to the round window niche without difficulty. Other structures identified in all specimens included the incudostapedial joint, stapedius tendon, pyramidal eminence and facial nerve via an extended myringotomy incision. The anterior middle-ear space was also successfully examined through an endoscope-guided anterior myringotomy. The opening to the eustachian tube was visualised and cannulated with a guide wire in all preparations in which this was attempted (n = 3).
CONCLUSIONS: The 1.3 mm, interventional sialendoscope allowed adequate visualisation of the eustachian tube, middle-ear space and round window niche, with interventional capabilities, in a cadaveric model. Our result validates the feasibility of its use for trans-tympanic drug delivery.