Extended Anterior Petrosectomy Through the Transcranial Middle Fossa Approach and Extended Endoscopic...

Area of Science:

• Neurosurgery
• Anatomy
• Surgical Approaches

Background:

• Petroclival tumors and ventrolateral pons lesions pose significant surgical challenges.
• Anterior petrous apicectomy requires precise anatomical understanding for optimal surgical corridor.
• Comparing transcranial middle fossa (TMF) and endoscopic transsphenoidal-transclival approaches is crucial for surgical planning.

Purpose of the Study:

• To quantitatively and qualitatively compare the anatomical exposure provided by the TMF and expanded endoscopic transsphenoidal-transclival approaches for petroclival and ventrolateral pons lesions.
• To assess surgical freedom and working angles for each approach.
• To determine the optimal approach for specific tumor locations.

Main Methods:

• A cadaveric study using 10 silicone-injected heads.
• Extradural drilling of the petrous apex and clivus via middle fossa and endonasal routes.
• In situ and frameless stereotactic navigation to define comparison points for working areas, bone removal, angles, and surgical freedom.

Main Results:

• The TMF approach yielded a significantly larger exposed area (21.03 cm²) and greater surgical freedom for lateral brainstem lesions compared to the endoscopic approach (5.29 cm²).
• Kawase's rhomboid area was well-defined with the TMF approach.
• The endoscopic approach provided adequate access for midline lesions not extending laterally beyond cranial nerve VI.

Conclusions:

• The TMF approach is advantageous for accessing lesions in the upper ventrolateral pons.
• The expanded endoscopic transsphenoidal-transclival approach is better suited for midline lesions.
• Anatomical comparison guides the selection of the most effective surgical strategy based on lesion location.