Tentorial meningiomas

Introduction

Tentorial meningiomas account for 3% to 6% of intracranial meningiomas and arise from the tentorium. They are characterized by multicompartmental growth and can involve the supra- and infratentorial space with involvement of several critical neurovascular structures, including the transverse and cavernous sinuses. Because the tentorium is a vast structure, there are a variety of surgical approaches that have been devised for resecting these lesions. Each of these different tentorial locations is associated with different Simpson-grade resections ( Chapter 41 , Fig. 41.2 ) and risks of morbidity. In this chapter, we present a case of a patient with a left lateral tentorial meningioma involving the transverse sinus.

Example case

Chief complaint: confusion

History of present illness

A 54-year-old, right-handed man with a history of coronary artery disease with coronary stent, hypertension, and hypercholesterolemia presented with confusion. His family states that over the past 3 months he had become increasingly forgetful in which he forgets his keys, where things are in the house, and where he is supposed to be. He saw a neurologist, and imaging was done that revealed this brain lesion ( Fig. 53.1 ).

Medications : Aspirin, clopidogrel, metoprolol, simvastatin.
Allergies : No known drug allergies.
Past medical and surgical history : Coronary artery disease with coronary stent 2 years prior, hypertension, hypercholesterolemia, cholecystectomy.
Family history : No history of intracranial malignancies.
Social history : Lawyer, no smoking, occasional alcohol.
Physical examination : Awake, alert, oriented to person, place, and time; Cranial nerves II to XII intact; No drift, moves all extremities with full strength.
Magnetic resonance venography : Stenosis of transverse-sigmoid junction but with flow.

	Michael R. Chicoine, MD, Washington University, St. Louis, MO, United States	Guilherme C. Ribas, MD, PhD, Hospital Israelita Albert Einstein, São Paulo, Brazil	Jacques J. Morcos, MD, University of Miami, Miami, FL, United States	Gelareh Zadeh, MD, PhD, Farshad Nassiri, MD, Toronto Western Hospital, Toronto, Canada
Preoperative
Additional tests requested	CT head Cerebral angiogram	Cerebral angiogram +/– embolization	Cardiology evaluation including evaluation of PFO Neuropsychological assessment	Angiogram/venogram Neuropsychological assessment Anesthesiology evaluation
Surgical approach selected	Left middle fossa craniotomy, partial mastoidectomy, lumbar drain, and possible abdominal fat graft	Left suprapetrosal craniotomy with posterior extension	Left posterior temporal craniotomy with lumbar drain	Left posterior temporal craniotomy
Anatomic corridor	Left middle fossa	Left posterior temporal	Left posterior temporal	Left posterior temporal
Goal of surgery	Maximal tumor resection, Simpson grade III	Simpson grade II	Simpson grade II, but likely Simpson grade IV	Maximal tumor resection, Simpson grade I if sinus nondominant and Simpson grade III if dominant
Perioperative
Positioning	Left three-quarter lateral/park bench	Left lateral park bench	Left supine with right rotation without compromising jugular veins	Left lateral
Surgical equipment	Lumbar drain Surgical navigation Surgical microscope Ultrasonic aspirator	Surgical navigation Ultrasonic aspirator	Lumbar drain Precordial Doppler Surgical navigation Surgical microscope Ultrasonic aspirator Bypass instruments	Surgical navigation Surgical microscope IOM (cranial nerve stimulator) Doppler Ultrasonic aspirator
Medications	Mannitol Steroids Antiepileptics	Antiepileptics	Mannitol Steroids Antiepileptics	Mannitol Steroids
Anatomic considerations	Vein of Labbe, transverse and sigmoid sinuses, facial nerve, temporal lobe	Local veins, transverse-sigmoid junction	Vein of Labbe, transverse-sigmoid junction, external ear canal	Vein of Labbe, transverse-sigmoid junction, pial-tumor interface
Complications feared with approach chosen	Venous sinus or vein of Labbe injury, cerebral edema, CSF leak, temporal lobe venous infarct	Venous injury, bleeding, cerebral edema	Venous injury, temporal lobe injury	Sinus thrombosis/injury, venous injury
Method of sinus repair	Avoid sinus injury by leaving tumor remnants; if small, occlude with muscle or gelfoam; for large, mobilize nearby dura to close or dura substitute; last resort is to occlude with preservation of vein of Labbe and collaterals	Attempt to coagulate site of bleeding, application of hemostatic agents, suture attempt with or without muscle plug, sinus ligation as last resort	Microsurgical repair with direct suturing, vein patch, or reimplantation of dural flap	Dominant sinus–tamponade with gelfoam, head down, primary repair; nondominant sinus–pack with thrombotic material if no tumor and reconstruction if tumor in sinus
Intraoperative
Anesthesia	General	General	General	General
Skin incision	C-shaped from anterior/superior aspect of tumor, curve to posterior aspect of tumor, and to left mastoid	Horseshoe	Question mark	Horseshoe
Bone opening	Left temporal, mastoid	Temporal	Left posterior temporal with removal of bone over transverse-sigmoid junction	Left posterior temporal
Brain exposure	Temporal lobe	Temporal lobe	Temporal lobe	Temporal lobe
Method of resection	Myocutaneous flap, temporal occipital craniotomy to expose superior aspect of transverse sinus, partial mastoidectomy to expose transverse and sigmoid sinuses, dura opened, internal debulking, establish plane between tumor and brain with telfa, remove tumor from venous structures if possible, reconstruct dura with dural substitute, mastoid defect filled with fat and cranioplasty with titanium mesh or bone cement	Left temporal horseshoe incision, left suprapetrosal craniotomy with posterior extension with basal burr holes anterior to tragus/superior to parietomastoid and squamous meeting points/superior to asterion with surgical navigation, drill inferior temporo-occipital bone margin, open dura with dural detachment from tumor from superior to inferior, special attention to identifying and preserving draining veins into transverse sinus, careful dissection of tumor superior/anterior/posterior surfaces from brain with aid of cottonoid patties, coagulation and division of basal aspect of tumor, removal of tumor with suction or ultrasonic aspiration depending on consistency ideally from outer surface to center, curettage and coagulation of residual tumor attached to basal dura	Posterior temporal craniotomy along skull base, drill bone around transverse-sigmoid junction, drain 30 cc of CSF from lumbar drain, open dura based on middle fossa floor paying attention to vein of Labbe, removal of tumor dural attachments, develop plane between tumor and pia, debulk tumor but leave tumor attached to Labbe and transverse-sigmoid junction until end, resection of residual component, chase tumor into sinus with sinus repair if needed with dural patch, pericranial duraplasty, wax air cells	Harvest pericranial graft for duroplasty, craniotomy based on navigation with 1-cm border with 2–3 burr holes along the middle cranial fossa with one on transverse-sigmoid sinus junction and two superiorly, bipolar dura to devascularize tumor from posterior middle meningeal artery, C-shaped dural opening with 1-cm margin based on tentorium, tumor removal with sequential tumor debulking and separation or arachnoid/pial surface with microscopic visualization, debulk tumor with ultrasonic aspirator and roll capsule inward until tentorium reached, sharp dissection from transverse-sigmoid sinus junction, coagulate sinus and tentorial edges, watertight dural closure with pericranium
Complication avoidance	Mastoidectomy, debulk tumor before separating from brain, identify and preserve sinuses and vein of Labbe, fill mastoid defect with abdominal fat	Low access to tumor, subtemporal dural devascularization, identification and preservation of draining veins	Drilling out transverse-sigmoid junction, careful inspection of vein of Labbe, no self-retaining retractors, leave portion attached to venous structures until end, leave residual on Labbe if needed, wax air cells	Pericranial graft, craniotomy with margins, coagulate dura to devascularize tumor, sequential debulking and capsule manipulation, sharp dissection from venous structures
Postoperative
Admission	ICU	ICU	ICU	ICU
Postoperative complications feared	Temporal lobe venous infarction, cerebral edema, CSF leak	Venous or sinus thrombosis, cerebral edema	Venous infarct, CSF leak, temporal lobe edema, seizures	Venous infarct, sinus injury
Follow-up testing	CT immediately after surgery MRI 3–4 months after surgery	MRI within 48 hours after surgery	Albumin 250 cc every 8 hours for 3–4 days MRI within 48 hours after surgery Lumbar drain clamped for 48 hours to monitor for CSF leak	MRI within 48 hours after surgery
Follow-up visits	7–14 days after surgery	2–3 months after surgery	10 days and 6 weeks after surgery	4–6 weeks after surgery
Adjuvant therapies recommended for WHO grade	Grade I–observation Grade II–radiation (SRS, hypofractionated, EBRT, or proton) Grade III–radiation (SRS, hypofractionated, EBRT, or proton)	Grade I–observation Grade II–radiation Grade III–radiation	Grade I–observation Grade II–radiosurgery Grade III–fractionated radiotherapy	Grade I–observation Grade II–radiation Grade III–possible re-resection if large, radiation, molecular analyses