Applied anatomy of clinical anatomic study of posterior tympanum related operation through the transmastoid facial recess approach

ZHANG Shanshan; TIAN Guangyong; DUAN Yongchang; XU Dachuan

doi:10.3969/j.issn.1672-2922.2014.01.029

Abstract：Objective To provide the anatomic data for operation on the posterior tympanum through the transmastoid fa-cial recess approach and measurement of related anatomic structure.Method 12 sides of 6 temporals had their mastoids out-lined and removing the latend wall of external auditory canal by an electric drill, and then the related structure of the posterior tympanum was exposed under surgical micmscope. Observation and Measurement of the suprameatal spine, facial nerve, fa-cial recess, pyramidal eminence, round window, oval window measured, ponticulus, pseudosubiculum andother related ana-tomical structure, statistical datas which were statistically analyzed. Result The average distances from auprameatal spine to short crus incus, The midpoint of pyramid segment of facial nerve canal were 20.06mm, 17.28 mm, respectively.The average distances from the midpoint of pyramid segment of facial canal to the posterior wall of external auditory canal was 4.67mm;The average length of facial nerve in the horizonial segment, the perpendicular paragraph was about 12.30mm,16.31mm,re-spectively. The average distance from pyramidal eminence to the anterior lip of round window niche,from oval window to round window niche,from incudostapedial joint to round window niche was 4.46 mm, 3.84mm, 3.89 mm, espectively. The aver-age distancs from the midpointof pyramid segment of facial canal to the lower endof the ponticulus, the lower end of the pseu-dosubiculum were 4.85mm, and 6.21mm respectively. chorda tympani nerve with facial nerve in the perpendicular paragraph was 48.3°,horizontal semicircular canal and facial nerve in the level paragraph was110.5°. Conclusion The position of ana-tomic structure in middle ear was constant and the relationship including distance and angle between anatomic structures changed in limited region.The anatomical parameters provide a reference value for avoiding the injury during the operation.