Otoendoscopic Tympanoscopy – Digital, Microscopic, Sialendoscopic and Rod Lens Endoscopic Visualization Compared

Background: In the last two decades, endoscopy established itself as an alternative to traditional1-3 (often indirect mirror based4-6) microscopic tympanoscopy and became strongly promoted for various endoscopic middle ear procedures7-12. This study evaluates the diagnostic potential of todays available endoscopic systems. Materials and Methods: Seven otologists rated the degree of visualization (in % of visible area of interest) and the digital image quality on visual analogue scale (VAS). Tympanoscopy (Fig 1) of eight middle ear landmarks16,17 was systematically performed13-15 in a human formalin fixed temporal bone. In addition to a microscope (OPMI 8SSTM ZEISS), a 1.3mm sialendoscope (KARL STORZ) , a 45° endoscope with or without digital image processing (SPIESTM KARL STORZ) and a chip on tip camera have been used for transcanal middle ear inspection. Figure 1: Systematic tympanoscopy (A) of 1: promontori (P), 2: round window niche (RWN), 3: stapes footplate (SF), 4: sinus tympani (ST), 5: facial recess (FR), 6: epitympanon (EPI), 7: Eustachien tube (ET), 8: hypotympanon (HT) evaluated by 45° rod lens (45), 45° rod lens SPIESTM (45S), 1.3mm sialendoscope (Sial), Chip on Tip (COT) and microscope (Mic).