Surgical treatment of petroclival meningiomas: Indications and limitations for the anterior petrosal approach

Abstract

Indications and limitations for the anterior petrosal approach for petroclival meningioma were discussed. We selected the anterior petrosal approach for tumors with an anterior extension into the Meckel's cave. Lateral and inferior limitations of this approach were the internal acoustic meatus and the inferior petrosal sinus, respectively. Tumors with an extension beyond the lateral or inferior limitation were resected using a combined petrosal approach. One of the anterior limitations was the cavernous sinus. Tumors in the cavernous sinus were treated using gamma-knife radiosurgery. Tumors with further anterior extension involving the intradural carotid artery or the optic nerve required combination with the orbitozygomatic approach. One of the medial limitations was the posterior clinoid process. To remove tumors attached here, the lateral cavernous wall needed to be removed. To expose the other medial limitation, the so called "central clival depression", another combination approach with either the posterior petrosal, lateral suboccipital, or transcondylar approach was required. The anterior petrosal approach is useful for petroclival meningioma when this approach is combined with other approaches according to the tumor extension.