Transplanum Polare Approach

see also Transplanum polare approach to the anterior mesiotemporal region

The transplanum polare approach is a microsurgical skull base technique used to access midline anterior cranial fossa lesions, particularly those involving the suprasellar region and anterior third ventricle.

• Craniopharyngiomas
• Tuberculum sellae and planum sphenoidale meningiomas
• Hypothalamic hamartomas
• Pituitary macroadenomas with suprasellar extension (select cases)
• Rathke’s cleft cysts with suprasellar component
• Optic pathway/hypothalamic gliomas

• Planum sphenoidale
• Tuberculum sellae
• Optic nerves and optic chiasm
• A1 segments of anterior cerebral arteries
• Lamina terminalis (may be opened for third ventricle access)
• Olfactory nerves
• Suprasellar cistern

• Position: Supine, head slightly extended and fixed
• Craniotomy: Bifrontal craniotomy, often with orbital roof osteotomies
• Exposure: Subfrontal or interhemispheric corridor to the anterior skull base
• Brain relaxation: CSF drainage via lumbar drain or cisternal opening
• Bone removal: Drilling of orbital roofs and planum sphenoidale for better access
• Dissection: Microsurgical dissection around critical neurovascular structures
• Optional: Opening the lamina terminalis to reach the third ventricle

• Direct midline access to anterior skull base and suprasellar region
• Wide bilateral exposure
• Useful for large or complex tumors not accessible endonasally

• Anosmia (olfactory nerve injury)
• Frontal lobe contusion from retraction
• Venous infarction (superior sagittal sinus or bridging veins)
• CSF leak if reconstruction is inadequate
• Cosmetic issues if frontal sinus is breached

• Endoscopic endonasal approach (EEA)
• Pterional or orbitozygomatic approaches
• Transcallosal interforniceal approach (for deeper third ventricular lesions)

• This approach is ideal when lesions extend above the chiasm or when endonasal access is contraindicated.
• Reconstruction of the skull base is critical to prevent postoperative CSF leaks.