An important complication of acoustic neuroma surgery is the development of a CSF fistula. A fistula is a potentially life-threatening complication and results in a fivefold increase in the incidence of meningitis.' The incidence of CSF rhinorrhea or CSF leakage from the wound is approximately 15% in most major series and does not differ significantly between the translabyrinthine and retrosigmoid (suboccipital) approaches.The usual path of CSF rhinorrhea following translabyrinthine surgery is from the posterior fossa dural defect into the middle ear cavity. After retrosigmoid tumor excision CSF can leak from the cerebellopontine angle into air cells that have been opened in the posterior internal auditory canal wall.2 CSF can also leak through the dural repair into the mastoid air cells and into the middle ear. A wound leak results from a direct communication between the skin and the posterior fossa. In order to prevent the development of CSF fistula, surgeons have relied on meticulous wound closure and postoperative CSF drainage.3 179 Skull