Cerebrospinal fluid rhinorrhea following acoustic neurinoma surgery. Technical note. The authors describe a method of preventing cerebrospinal fluid (CSF) rhinorrhea following surgery for acoustic neurinoma. Mastoid air cells exposed during craniectomy are skeletonized and packed with bone dust, then covered with Surgicel soaked with Tisseel fibrin glue. The use of this technique has reduced the number of acoustic neurinoma cases requiring secondary mastoidectomy for CSF leakage from 16% to 5%. 