Extended middle cranial fossa approach for vestibular schwannoma: technical note and surgical results of 896 operations.

From 1976 to 2006, 896 vestibular schwannomas were operated on using an extended middle cranial fossa approach. With this approach, the operative field can be extended according to tumor size and the facial and cochlear nerves can be preserved more easily with cooperation between the neurosurgeon and ENT surgeon. The mortality rate among 896 vestibular schwannoma patients was 0.3%. In the 760 initially operated vestibular schwannomas with total removal of the tumor, facial nerves were anatomically preserved in 715 or 94.1% of the cases. In 61.0% of 270 cases in which hearing preservation was attempted, hearing was preserved, and in 46.7% of those 270 cases useful hearing was preserved postoperatively. However, in the last 10 years the useful hearing preservation rate of the 140 attempted cases was 53.6%. Most of the complications of this approach were cerebrospinal fluid leakage; by using fat tissue, fibrin glue and spinal drainage from 1992 to 2005, cerebrospinal fluid leakage occurred in 59 or 10.6% of 569 cases, with 13 or 2.3% being repaired surgically. Moreover, in the last 10 years, the surgical results have improved along with improved surgical experience, improved instruments and better monitoring methods.