Figure 2.

Serial intraoperative photomicrographs of a left-sided retrolabyrinthine approach. (A) Mastoid surface after scalp elevation. The mastoid tip (mt), posterior margin of the external acoustic meatus (eam), spine of Henle (*), and linea temporalis (lt) are visualized. (B) After the initial bone is removed, the mastoid air cells are apparent, as is the contour of the transverse-sigmoid junction (tsj). The dissector is over the sigmoid sinus covered with cortical bone. (C) Bone covering the midportion of the sigmoid sinus (ss) has been removed. The dissector tip touches the dense cortical bone of the horizontal semicircular canal (hc). (D) A magnified view of facial nerve (fn) in the fallopian canal. The horizontal semicircular canal (hc) is also visualized. (E) A magnified view of the retrofacial air cells being removed with a diamond bur. The facial nerve (fn) in the fallopian canal is seen. (F) After the bone removal is completed, the presigmoid dura, endolymphatic duct (ed), facial nerve (fn), horizontal (hc) and posterior (pc) semicircular canals, and sigmoid sinus are exposed.