Convexity meningioma

Introduction

Meningiomas are among the most common primary brain tumor in adults, with an incidence that ranges from 1 to 8 per 100,000 people. One of the most common locations for these lesions is along the cerebral convexity, in which they account for 20% to 30% of the lesions. Even though convexity meningiomas are considered to be among the most surgically accessible brain tumors, these lesions can be associated with significant morbidity in which complications occur in about 10% of cases in most series. In this chapter, we present a case of a patient with a convexity meningioma.

Example case

Chief complaint: left arm and leg weakness

History of present illness

A 39-year-old, right-handed woman with a history of bipolar disorder presented with left arm and leg weakness. Over the past several months, she had lost a lot of her hand strength and coordination in which she is unable to button her shirt with her left hand. She has also noticed that it feels like her left leg is weaker than her right and that she has to drag it to move ( Fig. 44.1 ).

Medications : Lithium.
Allergies : No known drug allergies.
Past medical and surgical history : Bipolar disorder.
Family history : No history of intracranial malignancies.
Social history : Lawyer, no smoking or alcohol.
Physical examination : Awake, alert, oriented to person, place, and time; Cranial nerves II to XII intact; Left drift, left upper extremity 4+/5 except hand 3/5, left lower extremity 4+/5, right upper extremity/right lower extremity 5/5.

	Arturo Ayala-Arcipreste, MD, Hospital Juarez de Mexico, Mexico City, Mexico	Carlos E. Briceno, MD, Paitilla Medical Center, Panama City, Panama	Ricardo J. Komotar, MD, University of Miami, Miami, FL, United States	Michael W. McDermott, MD, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, United States
Preoperative
Additional tests requested	Angiogram (venous and arterial) EEG Neuropsychological assessment Psychiatry evaluation Neuroanesthesia evaluation	DTI fMRI MRA/MRV Neuropsychological assessment EEG	Psychiatry evaluation Angiogram with possible embolization	Cerebral angiogram with embolization
Surgical approach selected	Right parieto-occipital craniotomy	Right parietal craniotomy	Right parietal craniotomy	Right frontoparietal craniotomy
Anatomic corridor	Right parieto-occipital	Right parietal	Right parietal	Right frontoparietal
Goal of surgery	Simpson grade I	Simpson grade I	Simpson grade I	Simpson grade I

Perioperative
Positioning	Right three-quarters prone with left head rotation	Left dorsal decubitus with left head rotation	Right supine with left rotation	Right lateral
Surgical equipment	Surgical microscope Ultrasonic aspirator	Surgical navigation Surgical microscope Ultrasonic aspirator	Surgical navigation IOM (MEP) Ultrasonic aspirator	Surgical navigation Ultrasonic aspirator
Medications	Steroids Antiepileptics	Steroids Antiepileptics Mannitol, hypertonic saline	Steroids Mannitol	Steroids Antiepileptics Mannitol
Anatomic considerations	Vein of Trolard, SSS, branches of MCA and PCA	Motor and somatosensory cortices	Motor cortex, vein of Labbe and Trolard, SSS	Vein at posterior margin, SSS, primary motor and sensory cortices
Complications feared with approach chosen	Venous infarct	Venous infarct, motor deficit, sensory deficit, residual tumor	Motor deficit, venous infarct	Venous infarct
Intraoperative
Anesthesia	General	General	General	General
Skin incision	Linear	Lazy S-shaped incision	Linear	Inverted U-shaped crossing midline
Bone opening	Right parieto-occipital	Right parietal	Right parietal	Right frontoparietal
Brain exposure	Right parieto-occipital	Right parietal	Right parietal	Right frontoparietal
Method of resection	Linear incision calculated transversely with navigation, scalp flap preserving superficial temporal artery, craniotomy wide enough to cover the entire tumor and extra margin, dural tack up sutures, dural opening adjacent to tumor, devascularize tumor early on dural surface, protect brain surface with cottonoids, attempt to identify tumor-arachnoid interface, debulk center of tumor, once tumor volume has decreased sufficiently then sharp dissection of arachnoid from the tumor capsule, identify and protect venous structure at bottom of tumor, copious irrigation to allow hydrodissection, continue dissection until tumor completely removed, periosteum as dural substitute, insertion of subgaleal drain	Right parietal incision guided by navigation, harvest pericranium, parietal craniotomy guided by navigation, meticulous coagulation of dura, dural tack up sutures circumferentially incise dura and coagulate dural vessels leaving a wide margin (1–2 cm) of tumor-free dura, preservation of transdural veins, folding of involved dura over tumor to assist with tumor retraction, identify subarachnoid planes at tumor-brain interface, sharply opening planes avoiding pial violation, protect extracapsular en passage vessels, attempt en bloc resection with circumferentially dissecting tumor from brain with tumor coagulation, internal debulking if cannot be removed en bloc, protect brain with cottonoids, dissect deeper until tumor can be removed, inspect for dural tails and residual tumor nests, repair dural defect with pericranium or dural substitute, epidural drain	Right parietal craniotomy guided by navigation, open and resect involved dura, devascularize tumor early from dural feeders, protect veins (vein of Labbe and Trolard) and superior sagittal sinus if exposed, internal debulking with ultrasonic aspirator, dissect margins from brain, protect exposed critical structures, complete resection, dural substitute over dural defect	Subgaleal flap opening, pericranium raised separately, burr holes placed anteriorly and posteriorly 1.5 cm from midline and another laterally, right frontoparietal craniotomy guided by navigation, epidural space is dissected across midline, secondary flap is elevated across midline, sagittal sinus controlled with bipolar cautery and gelfoam, tack up sutures, tension of dura is palpated and measures to lower ICP are used if needed, margins of tumor marked on dura, cruciate dural opening over center of tumor and tumor debulked, after enough debulking dura is opened around tumor, brain-tumor interface developed, pericranium used for dural reconstruction, gaps in bone filled with bone cement
Complication avoidance	Devascularize tumor early, internal debulking of tumor, sharp dissection of tumor from arachnoid and critical structures, hydrodissection with irrigation	Devascularize tumor early, circumferentially remove dura, preservation of transdural veins, using dura for retraction, protect cortex, identify arachnoid planes, attempt en bloc resection	Devascularize tumor early, identify and protect critical venous structures, internal debulking prior to capsular manipulation	Pericranial harvest, bone flap in two separate pieces, internal debulking of tumor before developing interface
Postoperative
Admission	ICU	ICU	ICU	ICU
Postoperative complications feared	Cerebral edema, seizures, venous infarct, CSF leak	Cerebral edema, seizures, motor and sensory deficit, CSF leak, cognitive deficit	Motor deficit, venous infarct	Seizures, venous infarct
Follow-up testing	CT within 24 hours after surgery MRI 1 month and 4 months after surgery	MRI within 72 hours after surgery MRI 2 months after surgery	MRI within 24 hours after surgery	MRI within 48 hours after surgery
Follow-up visits	10 days after surgery Physical therapy evaluation	14 days after surgery	14 days after surgery	2 weeks after surgery 6–8 weeks after surgery
Adjuvant therapies recommended for WHO grade	Grade I–observation, surgery for residual Grade II–oncology/radiation oncology evaluation Grade III–oncology/radiation oncology evaluation	Grade I–observation Grade II–observation vs. radiation Grade III–radiation	Grade I–observation Grade II–radiation Grade III–radiation/chemotherapy	Grade I–observation Grade II–observation if Simpson grade I resection with MiB-1 <7% C, radiation if >7% Grade III–radiation