Parafalcine meningiomas

Introduction

Parafalcine meningiomas are among the most common locations for meningiomas, in which they account for 25% of meningiomas along with parasagittal meningiomas. Although they are in the same general vicinity as parasagittal meningiomas, parafalcine meningiomas are a different surgical entity, as they do not present themselves along the convexity surface. ^, This lack of convexity involvement means that superficial draining veins and the sagittal sinus must be traversed to reach the lesion. ^, In fact, there is a 10% to 20% complication rate among parafalcine meningiomas, which makes this location the third-highest rate of morbidity among all meningiomas after convexity and parasagittal meningiomas. ^, In this chapter, we present a case of a right parafalcine meningioma.

Example case

Chief complaint: left leg weakness

History of present illness

An 81-year-old, right-handed woman with hypertension, hypercholesterolemia, and dementia presented with progressive left leg weakness. For the past 5 to 6 months, she developed progressive difficulty with walking with left leg weakness. She underwent spine imaging that was negative. She, however, had scans of her brain done for dementia 4 years prior that revealed a small right parafalcine lesion. Repeat imaging showed significant growth of this lesion ( Fig. 47.1 ).

Medications : Aspirin, lisinopril, hydrochlorothiazide, and atorvastatin.
Allergies : No known drug allergies.
Past medical and surgical history : hypertension, hypercholesterolemia, dementia, hysterectomy, bladder surgery.
Family history : No history of intracranial malignancies.
Social history: Retired, independent with activities of daily living, no smoking or alcohol.
Physical examination : Awake, alert, oriented to person, place, and time; Cranial nerves II to XII intact and full vision to confrontation; No drift, moves all extremities with full strength except left lower extremity 4+/5.

	Victor Garcia-Navarro, MD, Tec de Monterrey Institute, Campus Guadalajara, Mexico	Michael W. McDermott, MD, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, United States	Peter Nakaji, MD, Barrow Neurological Institute, Phoenix, AZ, United States	Tony Van Havenbergh, MD, PhD, GasthuisZusters Antwerpen, Antwerpen, Belgium
Preoperative
Additional tests requested	Cardiology evaluation	Cardiology evaluation	Medical evaluation Physical therapy evaluation	MRV DTI Neuropsychological assessment
Surgical approach selected	Right frontoparietal craniotomy	Right parietal craniotomy	Left frontoparietal craniotomy	Right frontal craniotomy
Anatomic corridor	Right interhemispheric	Right interhemispheric	Left interhemispheric	Right interhemispheric
Goal of surgery	Simpson grade II	Simpson grade I	Simpson grade I	Simpson grade II
Perioperative
Positioning	Semilateral (right head rotation)	Supine neutral	Right supine with left rotation (left-side down)	Supine with head 20-degree right rotation and right-side down
Surgical equipment	IOMNavigationSurgical microscopeUltrasonic aspirator	Surgical navigation Ultrasonic aspirator Surgical microscope	Surgical navigation IOM (MEP, SSEP) Surgical microscope Endoscope	Surgical navigation IOM (MEP, SSEP) Surgical microscope Ultrasonic aspirator
Medications	Steroids Antiepileptic	Mannitol Steroids Antiepileptic	Steroids	Antiepileptic
Anatomic considerations	SSS, draining veins	Draining veins, motor cortex, medial surface of left hemisphere	SSS	SSS, draining veins, motor cortex
Complications feared with approach chosen	Dural sinus injury, brain retraction injury	Venous infarct, cortical injury	Brain retraction injury, SSS injury	Venous injury
Intraoperative
Anesthesia	General	General	General	General
Skin incision	Bicoronal linear/sinusoidal	C-shaped	Bicoronal linear	Bicoronal curvilinear
Bone opening	Bilateral frontoparietal eccentric to right	Bilateral frontoparietal eccentric to right	Left frontoparietal adjacent to SSS	Right frontal craniotomy just ipsilateral to sagittal sinus
Brain exposure	Right frontoparietal with 3 cm of normal brain exposed	Right frontoparietal	Left frontoparietal	Right frontal lobe
Method of resection	Bilateral frontoparietal craniotomy, burr holes on both sides of the sinus, craniotomy 3 cm larger than tumor. C-shaped dural opening, flap based on SSS, interhemispheric approach preserve cortical veins, devascularize tumor along falx and tumor surface, divide falx anterior and posterior to lesion, central debulking with ultrasonic aspirator, total resection with minimal brain retraction, dural coagulation if total removal not possible.	C-shaped incision based anteriorly, save pericranium for dural graft, mark midline, two right parasagittal burr holes 1.5-cm lateral to midline, remove bone flap and dissect across midline under direct visualization, second bone flap crossing midline to left, hemostasis of SSS with bipolar cauterization and gelfoam, tack up dural stitches, U-shaped dural opening based on SSS, detach tumor from falx, debulk tumor medially, identify lateral brain-tumor interface with microscope, incise falx after tumor removal beyond inferior attachment point, dural closure with pericranium and collagen sponge or fibrin glue, bone cement to fill in gaps and sand bone, irrigate with Betadine and place vancomycin in subgaleal space, closure with subgaleal drain	Meticulous positioning, coronal incision, burr hole on left edge of SSS, clear dura off of bone, rectangular craniotomy that is longer anterior to posterior as compared to laterally (approximately 2 cm width), dural opening based on SSS with preservation of veins, dissect down falx, open falx circumferentially around tumor, meticulous microscopic and endoscopic dissection, remove tumor	Right frontal craniotomy up to sagittal sinus, dural flap based on midline, approach the falx with preservation of draining veins, coagulation and cutting of dural base of tumor, debulk with ultrasonic aspirator
Complication avoidance	Preservation of draining veins, devascularize tumor early, avoid fixed retractors	Two piece craniotomy to cross SSS, detach early from falx, resect falx after tumor removal	Work from contralateral side, open falx circumferentially around tumor, microscope and endoscopic dissection and resection	Craniotomy up to sagittal sinus, preservation of draining veins, early coagulation of arterial feeders
Sinus repair if necessary	Compression, then muscle, then dural or periosteal flap position	Should not happen, direct pressure if roof of SSS, sutured closing if bleeding from lateral recess	Avoid craniotomy over sinus, otherwise tack up or cover with dural flap	Gelfoam and fibrin glue, periosteal patch, fascial patch, direct reconstruction
Postoperative
Admission	ICU	ICU	ICU	ICU
Postoperative complications feared	Vascular injury to superior sagittal sinus, cortical veins or cortex, venous stroke	Seizures, SMA syndrome, venous infarct	Right cortical injury, delirium	Venous injury, increasing motor deficit
Follow-up testing	CTA within 24 hours after surgery MRI within 72 hours after surgery	MRI within 48 hours after surgery	MRI within 48 hours after surgery Physical, occupational, speech therapy	CT within 24 hours after surgery MRI within 3 days after surgery
Follow-up visits	7–10 days after surgery	10–14 days after surgery 6–8 weeks after surgery	10–14 days after surgery	4 weeks after surgery
Adjuvant therapies recommended for WHO grade	Grade I–observation Grade II–observation Grade III–radiation	Grade I–observation Grade II–radiation Grade III–radiation	Grade I–observation Grade II–observation Grade III–radiation	Grade I–observation Grade II–radiation Grade III–radiation