Combined approach for lesions involving the cerebellopontine angle and skull base: experience with 20 cases--preliminary report.

Skull base tumors involving the clivus, petrous bone, and adjacent areas can be formidable lesions to successfully remove without causing significant neurologic deficits. At our institution in the last 5 years, twenty patients out of 103 patients with skull base tumors have undergone the supratentorial-infratentorial combined approach for removal of a neoplasm (nine schwannomas, six meningiomas, two epidermoids, one extensive basal cell carcinoma, one pontine cavernous malformation, and one basilar artery aneurysm). The average patient age was 43 years. The combined approaches in conjunction with the subtemporal exposure were retrosigmoid-retrolabyrinthine, retrosigmoid-translabyrinthine, or retrosigmoid-transcochlear. The choice depended upon the type and location of the lesion and the deficits noted preoperatively. Basically, the approach allowed communication of the middle fossa and posterior fossa by totally dividing the tentorium as much as necessary for effective surgical manipulations. Both sigmoid and superior petrosal sinuses are divided. There were no deaths. Postoperative neurologic deficits included temporary seventh nerve paralysis, sixth nerve weakness, fifth nerve sensory deficits, cerebrospinal fluid leaks, and hydrocephalus requiring a shunt. Overall, the results were very gratifying, considering the difficulties encountered in the surgical removal of these lesions.