The pineal gland is a small structure located in the center of the brain near the quadrigeminal cistern. It is supplied by arteries from the posterior circulation and drained by veins. The infratentorial supra cerebellar approach is described for accessing tumors of the pineal gland. This approach involves a midline incision, craniotomy above the torcula and transverse sinus, and dural incision between the transverse sinuses to retract the cerebellum and tentorium and expose the pineal region.

1. Dept of neurosurgery

2. Anatomy
 8 long and 4mm wide structure
 Midline and located in the area of quadrigeminal cistern
 Geometric centre of brain
 Extra-axial structure

3. Boundaries
 Anteriorly : post commisure and post 3rd ventricle
 Posteriorly: habenular commisure and vermis
 Superiorly: splenium
 Inferiorly: quadrigeminal plate and tectum

4. Arterial supply

5.  P1 : sup.colliculus, long and short circumflex
 P2: medial and lateral post choroidal
 P3 & P4: calcarine and parieto-occipital
 SCA: inf colliculus

6. Venous drainage

7. Tumors

10. Choice of approach
 Location of tumor
 Tumor morphology- lateral extent
 Displacement of great veins
 Angle of tentorium/ posterior fossa size

11. Approaches
 Post. Transcallosal – Dandy
 Trans- ventricular – Van wagenen
 Occipital transtentorial – Foerster and poppen
 Infratentorial- supracerebellar - krause

13. Infratentorial supra cerebellar
 Sitting position/ concorde position
 Table should be low
 Head flexed to keep tentorium parallel to floor
 Patient tilted forward

16. Exposure
 Incision – inion to c4 (expose spinous process of c2)
 Burrholes- above torcula , lateral aspect of transverse
sinus
 Craniotomy- exposing transverse sinus and torcula

18.  Dural incision – curved between lateral most aspect of
transverse sinus
 Dura retracted - tack up sutures
 Avoid excess retraction - sinus occlusion.

19. Technique
 Cauterize and divide adhesions and bridging vessels
between cerebellum and tentorium.
 Retract vermis post.inferiorly
 Open arachnoid over tumor
 Precentral cerebellar vein and vermian vein can be
sacrificed

20.  Small branches of choroidal and SCA branches over
tumor can be sacrificed
 Internal debulking
 Lateral wall dissection – choroidal vessels on the wall
can be sacrificed
 Inferior dissection- most dangerous ( brainstem)
 Finally – velum interpositum great vein at risk.