Schmidek

1. Surgical approach to
Falcine Meningioma
Eric C.Chang, Frederick G.Barker II, William T.Curry
Schmidek Chapter 33

2. Outline
• Intro
• Symptom and Presentation
• Radiographic findings
• Operative technique
• Postoperative care
• Summary

3. Intro
• 5-9 % of all intracranial meningioma
• Falcine meningioma often conceal by cerebral cortex
• Large falcine meningioma can grow superiorly to secondarily invade
SSS
• Classified based on their relationship to SSS

4. Symptom and Presentation
• Anterior third of SSS
• Frontal lobe syndrome
• Slow progressive symptom : short attention span, poor short-term memory,
personality change, apathy and emotional instability
• Sign of increase ICP : headache, papilledema, or optic atrophy
• Ddx : age-related dementia
• Frequently larger in size at the time of presentation than tumors in other
regions

5. Symptom and Presentation
• Middle third of SSS
• Spastic weakness and focal seizures that involve the contralateral foot and leg
• Patients to seek earlier medical intervention
• Posterior third of SSS
• Persistent headache and hemianopsia
• Visual hallucination
• Calcarine fissure : anopia to the inferior quadrant
• Tentorium cerebelli : anopia in the upper quadrants
• Large tumors : homonymous hemianopsia with macular sparing

6. Radiographic findings
• MRI : gold standard
• Extend bilaterally, acquiring a dumbbell or bi-lobed shape
• T1 : iso-hypo intensity
• T2 : hypo- to iso-intense  firm
malignant meningiomas  greater edema
• T1 c Gd : defining the tumor’s anatomic location, size, and cortical
involvement
• T2 and FLAIR : pial inversion of brain tumor

7. Radiographic findings
• Cerebral angiography
• Gold standard : digital subtraction angiography (DSA)
• tumor’s arterial feeding
• course, displacement, encasement
• patency of the superior sagittal sinus
• draining cortical veins

8. Radiographic findings
• MR angiography/venography
• limitation : flow-related artifacts, sensitivity to patient movement
• CT-angiography/venography (CTA/CTV)

9. Operative technique
• Anesthesia and preparation
• Reduced ICP : furosemide, mannitol,hyperventilation
• Preoperative plan involves resection or manipulation of the sagittal sinus :
precordial Doppler, intra-atrial venous catheter
• Somatosensory evoked potentials or direct cortical stimulation
• Positioning
• Anterior third of SS : supine position with the head slightly elevated
• Middle third of SS : supine with the head elevated and flexed, semiprone or
lateral approach
• Posterior third of SS : lateral position

10. Operative technique
• Neuro-navigation
• helpful in planning out the skin incision and the borders of the craniotomy
• Skin incision
• Anterior third of SS : bi-coronal incision
• Middle third of SS : horseshoe/U-shaped incision that has its base laterally
• Posterior third of SS : horseshoe/U-shaped incision that has its base toward
the occiput

11. Operative technique
• Craniotomy
• Encompass tumor margin 1-2 cm
• Tumors that extend across the midline : single piece or in two section
• Tumors that extend to the surface : avoid injury to underlying cortex and veins
• Dural opening
• U-shaped dura incision
• Elevating the dural flap medially to avoid tearing potentially important
bridging veins
• For bilateral tumors : the dura on the contralateral side is also incised

12. Operative technique
• Tumor resection
• Veins along the anterior third of the sinus can usually be ligated without
neurologic consequences
• Establish the anterior and posterior limits of the tumors
• The cortex should not be retracted more than 2 cm away from the falx and
the sinus
• The blood supply to the tumor from the falcine arteries is sectioned by
cauterizing
• The falx in the inferior-to-superior direction approximately 1 cm anterior and
1 cm posterior to the margins of the tumor

13. Operative technique
• Tumor resection
• Intracapsular enucleation is used to debulk the tumor
• The capsule is peeled away from the cortex
• In cases where there is pial invasion in areas involving eloquent brain, it is
advisable to leave a thin rim of tumor attached to the cortex rather than risk
debilitating neurologic compromise
• Mindful of the branches of the ACA, including the pericallosal and
callosomarginal arteries

14. Operative technique
• Management of sinus invasion
• Can grow and extend to involve the superior sagittal sinus
• Leaving a fragment of invasive tumor : higher rate of recurrence
• Attempting to achieve a Simpson I : the venous circulation at greater risk
• Based on their age, symptoms, tumor location, degree of sinus involvement,
and the robustness of the cortical venous collaterals

15. Operative technique
• Three main surgical strategies
• 1.Simple resection of the outer dural layer with the tumor and coagulation of
the inner layer at the sites of tumor attachment
• 2.For disease involving the superior sagittal sinus involves resecting the
invaded sinus wall(s) and repairing the sinus
• 3. Simple coagulation of residual tumor or resection of the involved sinus
without venous reconstruction

16. Operative technique
• Sindou and Alvernia, six-stage classification scheme for progressively
tumor invasion into the sinuses
• Type I lesions involve just the outer surface of the sinus wall
• Type II lesions have the tumor extending into the lateral recess of the superior
sagittal sinus
• Type III tumors infiltrate into the lateral sinus wall
• Type IV lesions tumor invaded into the roof of the sinus
• Types V and VI tumors completely occlude the sinus, with and without wall
invasion

17. Operative technique
• Closure
• Closed primary
• Dura plasty
• Bone flap or bone reconstruction

18. Postoperative care
• kept well hydrated to prevent delayed venous thrombosis
• Continue steroid to 72 hr then tape
• Anti-epileptic drug
• No history of seizure : continue 12 wk
• History of seizure : EEG no sign of seizure
• CT/MRI
• CTA
• Venous graft : anticoagulant