Sch 33 surgical approach to falcine meningioma
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Transcript of Sch 33 surgical approach to falcine meningioma
Surgical approach to Falcine MeningiomaEric C.Chang, Frederick G.Barker II, William T.Curry
Schmidek Chapter 33
Outline
• Intro
• Symptom and Presentation
• Radiographic findings
• Operative technique
• Postoperative care
• Summary
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
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
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
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
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
Radiographic findings
• MR angiography/venography• limitation : flow-related artifacts, sensitivity to patient movement
• CT-angiography/venography (CTA/CTV)
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
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
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
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
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
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
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
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
Operative technique
• Closure• Closed primary
• Dura plasty• Bone flap or bone reconstruction
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