Comparison Anterior Transpetrosal Approach with Endonasal Endoscopic Approach to the Petrosal Apex Lesion

Objective: Endonasal Endoscopic approach (EEA) has provided a less invasive surgery to middle skull base lesion, but has been limited in its applications due to potential complications. The aim of this study is to evaluate the feasibility of the purely EEA to tumors located in petrosal apex lesion and to compare EEA with anterior transpetrosal approach (ATP).

Methods: Fresh cadaver heads were studied with 4mm 0- and 30-degree endoscope and the microscope to develop the surgical approach and to identify surgical landmark.

Results: The transclival/transpterygoid approach by EEA was done with 4mm 0- and 30-degree endoscope and the ATP was performed by microscope. Both approaches to petrosal apex lesion visualized anatomical landmarks of middle skull base lesion.

Conclusion: By means of ATP, the tumors located in the petrosal apex lesion extended to middle and posterior cranial fossa can be accessed. By means of transclival/transpterygoid approach by EEA, the tumors situated in the clivus lesion and middle fossa can be approached. The transclival/ transpterygoid approach to the middle skull base by EEA allows for direct access to ventral lesion in upper- and petroclival region with no brain retraction and cranial nerve manipulation and damage of venous routes. It offers safe and effective access for appropriately selected patients.