Posterior internal auditory canal closure following the retrosigmoid approach to the cerebellopontine angle

The retrosigmoid approach is utilized in a variety of cerebellopontine angle and internal auditory canal procedures. Drill curettage of the posterior internal auditory canal enhances lateral exposure, however, this step may also increase the patient's risk for postoperative cerebrospinal fluid (CSF) otorrhea. Obliteration of perilabyrinthine air cells is technically difficult and muscle graft displacement frequently occurs. A technique for posterior petrous dural flap stabilization of a temporalis muscle plug has proved successful in decreasing the risk of postoperative CSF fistula following retrosigmoid surgery. Temporal bone air-cell anatomy, as it relates to retrosigmoid, posterior internal auditory canal surgery is reviewed. Our technique for internal auditory canal closure, with bone wax, bone paté, muscle grafts, and petrous ridge dural flaps is outlined.