Approaches to the Pineal Region Jan M. Eckermann, MD Department of Neurosurgery

Why go there? Pineal cell tumors: pineocytomas, pineoblastomas Germ cell tumors: teratomas, dermoid, epidermoid, endodermal sinus, embryonal cell, choriocarcinoma, germinoma, Astrocytomas, meningioma, ependymoma, metastatic tumors

The Pineal Region Anterior: Quadrigeminal plate, pineal body, habenular complex Lateral: Mesial temporal and occipital lobes, pulvinar Roof: Splenium Floor: Vermis

The Quadrigeminal Cistern Both supra- and infratentorial Anterior: Superior medullary velum, quadrigeminal plate, pineal gland Posterior: Thick arachnoid to tentorium Lateral: Loose arachnoid separates from ambient cisterns

The Quadrigeminal Cistern Structures within: Great vein of Galen Terminal internal cerebral veins Basal vein of Rosenthal Pericallosal veins Internal occipital veins PCA (P4) Posterior choroidal a.  cisterna velum interpositum

Approaches Supracerebellar – Infratentorial Occiptial – Transtentorial Combined Supratentorial – Infratentorial Transsinus

Supracerebellar – Infratentorial Sitting or concord position Midline or inverted U-shaped incision

Supracerebellar – Infratentorial

Supracerebellar – Infratentorial

Supracerebellar – Infratentorial

Occipital - Transtentorial Three – quarters prone position Operative side in dependent position Inverted J

Occipital - Transtentorial

Occipital - Transtentorial

Combined Supratentorial – Infratentorial Transsinus Semiprone position Operative side in dependent position Inverted J Craniotomy made in three pieces

Combined Supratentorial – Infratentorial Transsinus

Complications and Considerations Supracerebellar – Infratentorial: Air embolism Ventricluar collapse  SDH, pneumocephalus Not suitable for superior extending lesions Gravity retracting cerebellum

Complications and Considerations Occiptial – Transtentorial: Retraction of occipital lobes  visual field defects Disconnection syndrome Limited exposure of contralateral side Good view of quadrigeminal plate

Complications and Considerations Combined Supratentorial – Infratentorial Transsinus: Brain edema Venous infarcts Very wide exposure Consider primary re-anastomosis or patch graft

References Fossett TF and Caputy JC. Operative Neurosurgical Anatomy. Thieme: New York 2002 Haye AH and Laws ER. Brain Tumors. Churchill Livingstone: Edinburgh 1995