Acoustic neurinomas surgery by extended middle cranial fossa approach

The extended middle cranial fossa approach, which we have modified and extended, is a subtemporal transpetrosal transtentorial approach and is devised from the combination of Morrison and Kingʹs translabyrinthine-transtentorial approach and Bochenekʹs extended middle cranial fossa approach and is a Abstract The extended middle cranial fossa approach, which we have modified and extended, is a subtemporal transpetrosal transtentorial approach and is devised from the combination of Morrison and Kingʹs translabyrinthine-transtentorial approach and Bochenekʹs extended middle cranial fossa approach and is a team approach with cooperation between neurosurgeons and ENT surgeons. By means of this approach, the operative field can be extended according to tumor size and location, and through the wide operative field, safe operative procedures can be performed on the tumor, brain stem, AICA, facial nerve and cochlear nerve. During the past 20 years from 1976 to 1997, 560 cases of cerebellopontine angle tumor were operated on using the extended middle cranial fossa approach. Of the 560 cases acoustic neurinoma accounted for 454, meningioma for 54, epidermoid for 15, facial neurinoma for 11 and there were 20 other miscellaneous types. Reported herein are operative procedures and surgical results including a 0.4% overall mortality rate in 454 acoustic neurinoma operations. In the 401 initially operated cases of acoustic neurinoma the tumor was totally removed in 380 or 95% and, in 343 or 90% of the 380 cases, the facial nerve was anatomically preserved. Of the 380 cases, good function of the facial nerve (House-Brackmann Gr. I, II) was preserved in 288 (84%), fair function (GR. III, IV) in 41 (12%) and poor function (GR. V, VI) in 14 (4%). In 31 patients who underwent the facial-hypoglossal anastomosis to the sacrificed or preserved facial nerve with postoperative poor function, 2 are satisfied, 20 fairly and 9 not satisfied after anastomosis. In 76 cases or 52% of 145 cases in which hearing preservation was attempted, hearing was preserved postoperatively, and useful hearing, which we consider to be under 50 dB average pure tone loss and over 50% of speech discrimination, was preserved in 55 cases or 37% of the 145 attempted cases.