Apex petrosusa transmastoid yaklaşımın cerrahi anatomisi
Özet
The aim of the study is to demonstrate the surgical anatomy of transmastoid infralabyrinthine approach which is used in drainage of the lesions of apex partis petrosa. The relationships observed during dissections were also collaborated with the radiological findings. Mastoidectomy and middle ear dissection were performed in 37 temporal bones (30 cadaver sides and 7 bones) and by opening the infralabyrinthine, subcochlear and apex partis petrosa air cells, the whole tract of transmastoid infralabyrinthine approach was demonstrated. The topography of cochlea was described from the mastoid view. According to our results, in surgical position, the most inferior part of cochlea was at the same axial plane with the most inferior part of canalis semicircularis posterior and located 8,43 mm deep to proximal part of the mastoid segment of n. facialis. In order to perform a tract parallel to horizontal part of a. carotis interna, the tract should pass inferior and medial to cochlea and anterior and inferior to meatus acusticus internus. The mean coronal and axial angle of the route was 420 and 300 respectively. The tract was seen in close proximity with a. carotis interna if the angle between vertical and horizontal segments of a. carotis interna located more than 7 mm posterior to promontoryum. Our results demonstrated that the procedure could not be performed if bulbus jugularis mainly located in the middle ear and in close relation with cochlea. The procedure could be performed if the bulbus jugularis mainly located in the mastoid cavity and didn?t touch with n. facialis. Key words: Apex partis petrosa, anatomy, cholesterol granuloma, drenage, infralabyrinthine approach