Two-port endoscopy of the middle ear: endoscopic anatomy.

OBJECTIVES To shed light on the endoscopic anatomy of the middle ear seen on 2-port endoscopy and to describe potential clinical applications. DESIGN Anatomical structures were visualized by transmeatal or transtympanic rigid scopes of different angles and by a flexible scope in the eustachian tube. This arrangement ensured reciprocal guidance of the scopes and provided access to regions not seen otherwise. SETTING The Department of Anatomy 1, University of Vienna, Vienna, Austria. MATERIALS Forty tympanic cavities obtained from cadaver skulls without prior fixation were examined. Specimens did not show any abnormalities and were chosen without regard to age or sex. RESULTS Depending on the angle of view, rigid transmeatal or transtympanic endoscopes provided a full view of the entire tympanic cavity except for the epitympanum, access to which was barred by the incudomallear joint, the mallear folds, and the tympanic chord, but the epitympanum was well visualized through the flexible, steerable, transtubal scope. CONCLUSIONS Two-port endoscopy of the middle ear offers a full view of all structures in the tympanic cavity. The atraumatic transtubal approach to the tympanic cavity enhances the safety of transmeatal interventions and facilitates postoperative follow-up.