Surgical Strategy for and Anatomic Locations of Petroapex and Petroclival Meningiomas Based on Evaluation of the Feeding Artery

Background: The anterior transpetrosal (ATP) approach is the most appropriate approach for petroclival meningiomas (PCMs), which are typically located from the dorsum sellae to the upper border of the internal auditory meatus (IAM). Although neurosurgeons can resect over this area if the tumor is detached from the dura, tumors within the indication area for PCMs are not appropriate for the ATP approach, because it can be difficult to evaluate whether the tumor is attached to or only touching the dura. In this study, we investigated the tumor extension area based on an evaluation of the feeding artery to achieve a more accurate assessment of the dural attachment area. Methods: Using various angiography techniques, we studied 51 feeding arteries from 24 patients who had undergone surgical treatment of primary petroapex meningiomas and PCMs via the ATP approach. We measured the lower and posterior extension distances, the extension rate of the cavernous sinus and Meckel's cave, and the midline extension rate of the tumors. Results: The ascending pharyngeal artery (AphA) was the predominant feeding artery for tumors with lower extension. We determined that tumors extending over the lower border of IAM in cases in which the feeding artery was not the AphA can be resected using the ATP approach. Conclusions: This study shows an association between the predominant feeding artery and tumor extension area and demonstrates that an evaluation of the dural attachment area based on the feeding artery can aid selection of the appropriate surgical approach.