menigioma falcine parasagittal meningioma

1. Falcine and parasagittal
meningiomas
DR PRAVEEN K TRIPATHI
1

2. There is today nothing in the whole realm of
surgery more gratifying than the successful removal
of a meningioma with subsequent perfect functional
recovery…
Parasagittal meningiomas most interesting and
characterstic of all intracranial meningiomas..
—Harvey Cushing
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2016
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3. History
 1743, Lorenz Heister, performed the first documented attempt of
surgical treatment of a meningioma- applied a caustic of lime to the
tumor of a 34-year-old Prussian soldier
 1835, the first meningioma was successfully resected by Zanobi
Pecchioli.
 Cushing in 1922, suggested the term ‘Parasagittal’ for meningiomas
along the superior sagittal sinus (SSS).
 Olivecrona was the first to distinguish these meningiomas according to
the site of attachment along the SSS 29 August
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4. INTRODUCTION
 Meningiomas are the most common primary brain and central nervous
system tumor (incidence rate, 6.29 per 100,000 persons).
convexity
(19% to 34%)
parasagittal
locations
(18% to 25%)
sphenoid wing
and middle
cranial fossa
(17% to 25%)
anterior skull
base (10%)
posterior fossa
(9% to 15%)
cerebellar
convexity
(5%)
clivus (<1%).
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5. PATHOLOGY
 Meningioma’s cell of origin is believed to be the
arachnoid cap cell.
 The arachnoid villi protrude into the venous sinuses.
 The venous endothelium is in contact with all or a portion
of the arachnoid villi.
 In the latter case, these cells are referred to as arachnoid
cap cells.
 The rest of the granulation is covered by a fibrous capsule.
 Nearly 50% invade the sinus, 50% get secondary
attachment to the falx and 25% are bilateral.
 Falcine meningioma arises from the falx cerebri or
inferior sagittal sinus and may rarely invade the SSS.
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6. PATHOPHYSIOLOGY
raised intracranial
pressure,
disruption of
cortical
electrophysiology
or
direct mass
effect on
adjacent neural
structures.
Clinical symptoms
from meningiomas
develop as a result of
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7. DEFINITIONS
Falcine Meningiomas
 Falcine meningioma, as defined by Cushing, arises from the falx, is completely concealed
by overlying cortex, and typically does not involve the superior sagittal sinus
Parasagittal Meningiomas
 Cushing and Eisenhardt defined a parasagittal meningioma as one that fills the parasagittal
angle, with no brain tissue between the tumor and the superior sagittal sinus.
 Other investigators, such as Olivecrona, Elsberg, and Merrem, grouped all parasagittal
meningiomas with falcine meningiomas
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8. DEFINITIONS
Anatomic differentiation of convexity, parasagittal and falcine meningiomas.
A, Convexity meningiomas have no affiliation with the SSS and are separated from the SSS by intervening brain tissue
that presents to the surface (arrow).
B, Parasagittal meningiomas fill the angle between the convexity and falcine meningioma. They are at least attached to
one wall (arrow) of the SSS and brain tissue at the angle is displaced laterally or deep.
C, Falcine meningiomas primarily arise from the falx and are cloaked from the surface by convexity brain tissue (arrow).
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9. CLASSIFICATION OF FALX MENINGIOMA
 Falcine meningiomas can be divided into anterior, middle and posterior types, depending
on their origin on the falx.
 The anterior third extends from the crista galli to the coronal suture,
 The middle third from the coronal suture to the lambdoid suture,
 The posterior third from the lambdoid suture to the torcula.
 Yasargil classified falcine meningiomas as outer and inner types.
 Outer falcine meningiomas arise from the main body of the falx in the frontal (anterior or
posterior), central parietal, or occipital regions.
 Inner falcine meningiomas arise in conjunction with the inferior sagittal sinus.
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10. CLINICAL FEATURES- ANTERIOR-THIRD
MENINGIOMAS
 Parasagittal and Falx meningiomas are considered together, as they have a similar
clinical presentation.
 Anterior-third meningiomas, located between the crista galli and the coronal
suture, have a more insidious onset and often attain a large size before diagnosis.
 Headache is the predominant symptom and may be present for years followed by
gradually progressive impairment of memory, intelligence and personality changes.
 Generalised epilepsy is a presenting symptom in 25–30% of patients.
 Ataxia, tremor and ipsilateral facial pain may, occasionally, accompany a large
meningioma in this location and thus may be misdiagnosed as a posterior fossa
tumour.
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11.  Tumours in the middle-third, from the coronal suture to the lamboid
suture, classically present with contralateral focal motor or sensory
epilepsy followed by progressive weakness of the contralateral lower
limb.
 These tumours are detected at an early stage because of focal
epilepsy.
 Bilateral tumours may, occasionally, give rise to bilateral disturbances
and, rarely, paraplegia that may be wrongly attributed to spinal
pathology
CLINICAL FEATURES- MIDDLE-THIRD
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12. Tumours in the posterior-third between the lambdoid suture and the
torcular herophili may present with
 Features of raised intracranial pressure alone.
 The only characteristic sign, a homonymous field defect, either
quadrantanopic or hemianopic, may not be noticed by the patient.
 Epilepsy is uncommon.
CLINICAL FEATURES- POSTERIOR-THIRD
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13. IMAGING
 CT best reveals the chronic effects of slowly growing mass lesions on bone remodelling.
 Calcification in the tumour (seen in 25%) and hyperostosis of overlying skull may be
seen.
 MR imaging reveals a number of characteristics highly suggestive of meningioma.
 These include a tumour which is
o Dural-based and isointense with grey matter,
o Demonstrates prominent and homogeneous enhancement (95%),
o Frequent cerebrospinal fluid/vascular cleft(s) and often an enhancing dural tail (60%).
 However, approximately 10–15% of meningiomas have an atypical appearance on MR
images, mimicking metastases or malignant gliomas.
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14. IMAGING
CT scan showing a middle-third falx meningioma
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15. CT scan showing a large anterior-third falx meningioma 29 August
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16. CT scan of the brain showing
a large posterior-third falx
meningioma
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17. 3.3a. Pre-contrast Axial T1 Wtd MRI 3.3b. Axial T1 Wtd MRI (C+) 3.3c. Coronal T1 Wtd MRI (C+)
60 year-old lady had MRI of the brain
following a seizure.
A dural-based intensely enhancing
(arrows) meningioma arising from the
right side of the falx.
Diagnosis: Falcine Meningioma
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18. IMAGING
 Parasagittal meningiomas may pose a difficult surgical
challenge since venous patency and collateral anastomoses
have to be clearly defined for correct surgical planning.
 Contrast-enhanced magnetic resonance venography (CE-MRV)
provides additional and more reliable information concerning
venous infiltration and the presence of collateral anastomoses
compared with phase contrast (PC) sequences
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19.  Tumours in the mid and posterior-third may be investigated by
angiography, mainly to assess the status of the SSS and the distribution of
the cortical veins.
 Middle PSMs depress the pericallosal arteries and the anterior tumours
displace these vessels posteriorly and downwards.
 The anterior cerebral artery may be displaced to the same side and bilateral
tumours often cause spreading of the pericallosal and callosomarginal
arteries in opposite directions and outline the extent of the tumour
IMAGING
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20. DECISION MAKING
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Their natural growth rate,
Radiological characteristics,
Location;
The patient’s clinical status
Assessment balancing the potential morbidity of conservative
versus invasive treatment.
The treatment of
meningiomas
depends on

21. DECISION MAKING- “CLASS” algorithm
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 Dr. Joung Lee and his group at the Cleveland Clinic designed the “CLASS” algorithm for the
treatment of all meningiomas.
 This algorithm compares negative features (comorbidity, location, and age) against benefits (size
and symptoms) and assigns a score:
 Comorbidity (−2 to 0)
 Location (−2 to 0)
 Age (−2 to 0)
 Size (0 to 2)
 Symptoms and signs (0 to 2)
 Patients with a score of +1 or higher had a 1.9% rate of poor outcome; those with a score of 0 to 1
had a 4% rate of poor outcome; and of those with a score of −2 or less, 15% had a poor outcome.

22. DECISION MAKING - CONSERVATIVE
TREATMENT
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 Around two thirds of asymptomatic meningiomas do not continue to grow and may be observed at
appropriate time intervals.
 Absolute growth rates of meningiomas vary between 0.03 and 2.62 cm3 per year.
 Some authors recommend the surgical resection of meningiomas when the tumor growth rate is greater than 1
cm3 per year.
 Radiological features such as partial or complete calcification is related to slow growth rate or absence of it,
so these tumors may be kept only under observation.
 Meningiomas that remain asymptomatic but show displacement and compression of delicate structures as
spinal cord, optic nerve, chiasm, and brainstem, or with considerable surrounding edema, should be
considered for early treatment.
 Observation alone, with periodic neurological and MRI evaluation follow-up, first at 3 months, second at 6
months, and then every year, is reasonable for asymptomatic or minimal symptomatic elderly patients with
fewer than 10 to 15 years of remaining life expectancy.

23. INCIDENTAL MENINGIOMAS
 Currently, incidentally discovered meningiomas represent 10% to 20% of all meningiomas
 Because they exhibit no growth or slow linear growth, the majority of asymptomatic,
incidental meningiomas may be observed without surgical intervention.
 Specific imaging and patient characteristics associated with more rapid meningioma growth
rates have been identified.
 The likelihood of tumor growth is higher in young patients and tumors larger than 3 cm .
 Tumors that lack calcification and are hyperintense on T2-weighted MR-imaging are also
more likely to display an aggressive growth pattern.
 For each clinical situation, the decision to recommend surgery should be evaluated on an
individual basis, incorporating patient comorbidities, age, observed growth rate, and image-
based predictive factors for growth.
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24. INCIDENTAL MENINGIOMAS
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25. INCIDENTAL MENINGIOMAS
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26. INCIDENTAL MENINGIOMAS
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27. Indications
 The clearest indication for surgery is the development of neurologic
symptoms attributable to the tumor.
 Rarely, tumors may present with significant hyperostosis or skin ulceration,
necessitating surgical intervention for cosmesis and/or reducing the risk of
infections.
 Meningiomas associated with significant peritumoral edema may also carry
an increased epileptogenic potential and represent an indication for early
removal, even if tumors are relatively small in size.
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28. Contraindications
Contraindications:
 Small tumors with no edema, asymptomatic tumors, and tumors in
unfit or elderly patients (older than 70 years) should be considered
relative contraindications
 Tumors closely associated with the sensorimotor cortex may cause
symptoms even when relatively small and should be strongly
considered for surgery rather than observation or conservative
management. 29 August
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29. Preoperative Evaluation
 Preoperative evaluation minimizes the risk of perioperative morbidity and
mortality, allows an appropriate estimation of the risks of surgery.
 There are three important tumor characteristics -significantly impact the
objective and approach to resection of these tumors.
 These include the
(1)Involvement of the SSS and development of collateral veins,
(2)The extent and type of bone involvement, and
(3)The presence of edema and brain invasion in adjacent eloquent cortices
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30. Preoperative Evaluation
 The evaluation of SSS patency, invasion and the development of collateral venous pathways
are performed with contrast-enhanced MR-venography (CE-MRV).
 DSA is still performed if tumor embolization is considered or if arterial supply to the tumor
needs to be better defined
 These may reveal significantly dilated scalp veins and diploic veins in addition to engorged
cortical venous collaterals.
 These supplementary collateral venous pathways play a critical role in venous drainage,
especially in the setting of parasagittal meningiomas causing occlusion of the middle or
posterior third of the superior sagittal sinus.
 When possible, surgical approaches should avoid transgression of these structures with
tailored scalp incisions and bone flaps.
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31. SUPERIOR SAGITTAL SINUS INVOLVEMENT
Clinical classification of parasagittal meningiomas. Parasagittal meningiomas may be classified based on their relationship
with the superior sagittal sinus (SSS). A, Type I meningiomas are attached only to the outer surface of the SSS. B, Type II
meningiomas invade the SSS but the lumen remains patent. C, Type III meningiomas invade the SSS and cause its occlusion.
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32. Sindou Grading system for meningioma
invasion of the superior sagittal sinus-2006
coronal section through superior sagittal sinus (SSS).
 Type I = attachment to lateral wall of sinus;
 Type II = invasion of lateral recess;
 Type III = invasion of lateral wall;
 Type IV = invasion of lateral wall and roof;
 Type V = total sinus occlusion, contralateral wall spared;
 Type VI = total sinus occlusion, invasion of all walls
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33. Preoperative evaluation
BONY CHANGES
 Bony changes associated with meningiomas can be caused by hyperostotic changes or direct bone invasion by
tumor.
 Hyperostotic changes are generally considered a benign form of inductive ossification caused by tumoral
increases in alkaline phosphatase production.
TUMOR AND BRAIN CHARACTERISTICS
 Postcontrast MR imaging often reveals trailing linear enhancing structure along its dural attachment referred
to as the “dural tail.”
 The dural tail is not specific to the diagnosis of meningioma, but its management continues to be a point of
controversy.
 Although evidence suggests that most of the dural tail is an imaging correlate of dilated meningeal vessels and
dural congestion, many still advocate extensive resection of the dural tail believing that it can contain tumor.29 August
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34. Preoperative evaluation
 Identification of a T2-weighted hyperintense arachnoid cleft between tumor and brain is
often indicative of a distinct anatomic plane.
 Absence of an arachnoid cleft in combination with significant peritumoral edema may be
indicative of pial vessel parasitization and/or brain invasion.
 Addressing brain invasion is a key aspect in the operative management of parasagittal
meningiomas.
 If extrapial resection is not possible in an area of eloquence, a small amount of tumor may be
left attached to the cortical surface and observed postoperatively.
 For tumors near eloquent areas with variable representation, such as Broca’s and Wernicke’s
area, fMR imaging or awake surgery with mapping is valuable in elucidating their anatomic
relationship and determining risks of resection.
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35. EMBOLIZATION
 It can be used to reduce intraoperative blood loss, which can potentially
reduce surgical complications and improve overall outcome.
 The surgeon must balance the use of embolization against its known
complications (6%), including ischemic stroke, hemorrhage, and acute
cerebral edema.
 Rarely found it necessary to embolize parasagittal meningiomas of any size,
because the source of tumor bleeding is readily apparent at the working
surface and can be controlled with meticulous hemostasis.
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36. When to perform?
 Timing of parasagittal meningioma resection is influenced by the extent of SSS
involvement.
 Because acute surgical obstruction of the patent SSS can cause significant cerebral
edema and venous infarction,
 A tumor causing partial obstruction may be followed closely to observe for the development
of complete occlusion, allowing that the intracranial component of the tumor does not
greatly increase in size, cause symptoms, or encroach on large adjacent superficial
anastomosing veins.
 Alternatively, an asymptomatic meningioma without evidence of invasion into the SSS
may require intervention at the earliest sign of growth so that a complete resection can
be performed without entering the SSS.
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37. Guidelines
Unfortunately no class I guideline exist.
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38. Technique Of Parasagittal Meningioma
Resection
 The technique of parasagittal meningioma resection is based on the following principles:
1. A bicoronal incision is preferred because it allows maximal vascularity to the skin,
especially if subsequent craniotomies are performed.
2. A pericranial flap is reflected separately.
3. Multiple bur holes are made in close approximation to one another at the periphery of the
tumor.
4. Bur holes straddling the superior sagittal sinus allow safe separation of the dura from the
bone.
5. Microsurgical separation of the tumor capsule from surrounding cortex is performed
while preserving the vessels overlying the normal cortex. 29 August
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39. Surgical principles in the resection of falcine
meningioma
 The surgical principles in the resection of falcine meningiomas include the
following:
1. Microsurgical interhemispheric exposure is achieved.
2. For a unilateral tumor, early devascularization along the falx is preferred.
3. For larger tumors, central enucleation allows subsequent microsurgical
separation of the tumor capsule from surrounding arachnoidal areas.
4. Liberal use of cottonoid pledgets along the dissection plane helps avoid
surrounding cerebral cortex injury and protects the pericallosal arteries in
the inferior margin of the dissection. 29 August
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40. Simpson Grading System 1957
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To further minimize the recurrence of meningiomas, an additional dural margin of about 2 cm
around the tumor is removed (Grade 0 removal). – Al Mefty etal 1993

41. Modified Shinshu Grade or Okudera-
Kobayashi Grade 1992
GRADE DESCRIPTION
I Complete microscopic removal of tumor and dural attachment with any abnormal bone
II Complete microscopic removal of tumor with diathermy coagulation of its dural attachment
IIIA Complete microscopic removal of intradural and extradural tumor without resection or coagulation of its
dural attachment
IIIB Complete microscopic removal of intradural tumor without resection or coagulation of its dural
attachment or of any extradural extensions
IVA Intentional subtotal removal to preserve cranial nerves or blood vessels with complete microscopic
removal of dural attachment
IVB Partial removal, leaving tumor of <10% in volume
V Partial removal, leaving tumor of >10% in volume, or decompression with or without biopsy 29 August
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42. Positioning
Anterior third tumors
 A supine position with the head and neck in a neutral or gently flexed position will permit direct access to the tumor.
Middle third tumors
 A supine semisitting position with slight head and neck flexion will often allow direct access to the tumor.
Or
 Lateral with their head elevated so that the scalp over the tumor is at the highest point in the field.
Parasagittal tumors located along the posterior third of the sss
 A prone position with the head and neck in neutral or slightly extended position can provide direct tumor access.
Or
 Another positioning option for tumors in this location includes placing the patient three quarters prone with the tumor
below the midline, allowing for the brain to fall away with minimal retraction
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43. Positioning
 Parasagittal meningioma.
 Positions and incisions for operation.
The approximate center of the tumor is
the highest point.
(A) Anterior third of sagittal sinus.
(B) Middle third of sagittal sinus.
(C) Posterior third of sagittal sinus.
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44. Incision
 Parasagittal meningiomas of the anterior third of SSS are exposed via a bicoronal incision.
 Meningiomas of the middle and posterior third of the sss can be exposed through a bicoronal, S-
shaped or a U-shaped incision.
 Bicoronal or S-shaped incisions are centered over the tumor mass in the anteroposterior plane and
should permit exposure of the uninvolved side of the sss.
 U-shaped incisions for parasagittal tumors should extend at least 2 cm past the midline to provide
exposure to the uninvolved side of the sss.
 U-shaped incisions should have a wide base that is 1.5 times the length of the pedunculated flap
to ensure adequate perfusion to the distal portions.
 During incision, it is important to attempt to maintain larg anastamotic collaterals that may have
developed within the scalp and diploe to prevent venous congestion, brain swelling, and/or
infarction
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45. SSS involvement- choices
There are three choices.
1. Ligate the sinus. This option carries the risk of venous infarction and can be performed only in
the anterior third.
2. Leave the portion of the tumor attached to the sinus in place, with the understanding that this
will most likely grow and possibly cause slow occlusion of the sinus with the formation of
collateral venous channels, allowing easier resection in the future.
3. Resect the portion of the sinus involved and then repair the sinus primarily or with a patch.
 Decisions regarding the sinus, however, should be individualized for each case according to
several factors: the patient’s age and symptoms, patency of the sinus, location of the tumor, and
cortical venous collateral system.
 A truly occluded sinus can be totally excised at any point. 29 August
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46. SSS involvement
 Type I tumors can be peeled from their attachment to the dura overlying
the SSS
 After this is accomplished, the external layer of dura is cauterized to
achieve a Simpson grade II resection.
 If type II tumor, perform a Simpson grade III resection.
 Type III tumors allow for ligation and resection of the SSS. Because
immediately adjacent veins that enter the SSS just anterior or posterior to
the obstruction represent important collaterals, it is imperative that these
vessels not be compromised in an attempt for greater resection. 29 August
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47. For type I tumors, the tumor is peeled from the dura of the SSS and this area of attachment is cauterized
(Simpson grade II resection). Areas of dural attachment can be resected (bold line) up to within a few millimeters
of the SSS.
For type II tumors, a layer of tumor residual invading the wall of the SSS is cauterized and left in situ. Areas of
dural attachment can be resected (bold line) up to within a few millimeters of the SSS. Tumor within the sinus is
not treated (Simpson grade III resection).
For type III tumors, the occluded SSS is ligated and resected (bold line), along with involved convexity and/or
falcine dura (arrowheads)( Simpson grade I resection). 29 August
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48. MATERIALS USED TO REPAIR SSS
 The main materials used to repair vessels are
 The autogenous great saphenous vein,
 Neck superficial veins, and
 Artificial blood vessels such as Dacron and polytetrefluoroethylene, which
are suitable for the larger diameter of arterial system, whereas silicone tubing
is suitable for dural venous sinuses and veins.
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49. surgery
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Surgical approach to parasagittal meningiomas.
A, After pericranial graft harvest, two burr holes are placed on
the opposite side of the superior sagittal sinus (SSS),
approximately 1.5 cm off the midline and one burr hole is
placed on the convexity ipsilateral to the tumor.
B, The dura is opened and reflected contralaterally. Care is
taken to avoid cortical veins that may cross to bridge with the
SSS. Extracapsular dissection and intratumoral debulking is
performed until the tumor is removed.
C, After the principal mass is removed, areas of dural
attachment to the convexity and/ or falx are examined and
extent of SSS involvement ascertained.

50. surgery
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Parasagittal meningioma with a patent posterior
third of the sagittal sinus and hyperostosis invading
the skull.
The hyperostotic, invaded bone is divided into
pieces before it is removed.
The tumor is debulked with an ultrasonic aspirator,
and the capsule is separated from the cerebral cortex.
The pial plane is maintained, and utmost attention
is paid to preserving the cortical veins.
The tumor capsule is then amputated along the
sinus, and a piece of tumor invading the sinus is left.

51. Complications
 New neurological deficits (approximately 2%)
 Wound infection (5%)
 Cerebrospinal fluid leak (1%)
 Postoperative hematoma (5%)
 Seizure (1%)
 Air embolism (1%) and significant blood loss.
 Permanent neurologic deficit and worsening of functional status (approximate 10%)
occurs as a result of postoperative brain swelling and/or venous infarction, likely from
acute occlusion of important collateral vessels
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52. 29 August
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53. 29 August
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54. SSS INVOLVEMENT
 Surgical microscopic radicality was
unexpectedly difficult to achieve.
 Gammaknife radiosurgery was a
useful adjunct but only in patients
with tumors of low proliferative
index.
 It should probably be used as part of
the initial surgical management.
 As expected, treatment results for
these patients seem to have
improved during the last decades but
recurrence and malignancy remained
a problem, which is not always
solved by repeated radiosurgery.29 August
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55.  retrospectively evaluated surgical experience from June 2004 to January 2010. Seventy
patients harboring falcine meningiomas were included and submitted for surgical resection.
 The patients were divided into three main groups: anterior third 32 patients (Group A),
middle third 15 patients (Group B), 23 patients in the posterior third of falx (Group C).
 Group A meningiomas had a better outcome due to the position they were in, the tumor
and surrounding structures.
 In the middle and posterior third, resection of sagittal sinus is a factor of a bad outcome,
due to cerebral infartion. 29 August
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56. Venous preservation–guided resection: a changing
paradigm in parasagittal meningioma surgery
CONCLUSION:
 Analysis of the data obtained in the 67
patients confirmed good outcome and long-
term tumor control following a surgical
strategy aimed to preserve venous outflow.
 These findings and the results of the
authors’ analysis of the literature emphasize
that the goal of radical tumor resection
should be balanced by an awareness of the
increased surgical risk attendant on
aggressive management of the SSS and
bridging veins. 29 August
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57. PROGNOSIS -PARASAGITTAL AND FALX
MENINGIOMA
 Rate of recurrence of parasagittal and falx meningioma significantly increases in cases of
non-radical resection of tumour.
 Aggressive surgical treatment presents several hazards and carries an increased risk of
unsatisfactory outcome; the risk of recurrence, however, is significantly decreased.
 Recurrence rates after
 Total resection of meningiomas involving the sagittal sinus wall range from 5 to 9%;
 Those after sub-total resection accompanied by sinus wall excision range from 16 to 17%;
 After sub-total resection of the tumour is approximately 29%;
 And after partial resection of the tumour it is approximately 39%.
 If a conservative and less aggressive approach is adopted, then the patient has to be
informed regarding the prognosis and may be given the option of adjuvant radiosurgery.
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58. 29 August
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