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Cerebellopontine Angle and Internal Auditory Canal Meningiomas
Built from Haynes-Glasscock-Shambaugh Surgery of the Ear, Seventh Edition
What’s inside
10 sections · 102 slides
Overview
- Scope of this topic
Epidemiology and origin
- Frequency of intracranial meningioma
- Relationship between CPA and IAC disease
- Patient demographics and predisposing factors
- Posterior surface of the petrous temporal bone
- Internal acoustic meatus in the posterior fossa floor
Pathology and grading
- Cell of origin and gross characteristics
- Microscopic hallmarks of meningioma
- Meningioma with large psammoma bodies
- Whorls, psammoma bodies and syncytial cells
- Immunohistochemistry and cytogenetics
- World Health Organization grading
- Behaviour of each WHO grade
- Grade-based criteria and subtypes
- WHO-grade meningioma characteristics
Clinical presentation
- Determinants of the clinical picture
- Growth rate and symptom specificity
- Hydrocephalus and raised intracranial pressure
- Peritumoral oedema as an indication for treatment
- Symptoms by compressed cranial nerve
- Presenting symptoms based upon the lesion location
- Clinical evaluation and threshold for imaging
Imaging
- General radiographic features
- Non-contrast computed tomography appearance
- Bone windows on computed tomography
- Contrast-enhanced computed tomography
- T1-weighted magnetic resonance imaging
- T2-weighted magnetic resonance imaging
- Cerebellopontine angle mass on T2-weighted imaging
- Dural tail and tumour centring
- Enhancing angle mass extending into the canal
- Angiographic appearance
- Recommended imaging protocol
Differential diagnosis
- Lesions to consider in the angle
- Separating meningioma from vestibular schwannoma
- Meningioma vs. vestibular schwannoma MRI characteristics
Treatment strategy
- The three treatment options
- Factors driving the treatment decision
- Incidental meningioma and natural history
- Proportion of tumours that actually grow
- Cited risk factors for tumour growth
- Surveillance imaging schedule
- Triggers for intervention during observation
- Goals of stereotactic radiosurgery
- Advantages and disadvantages of radiosurgery
- Outcomes after radiosurgery: multicentre series
- Outcomes after radiosurgery: CPA meningioma series
- Indications for radiation in this practice
- Fractionated radiotherapy versus single-dose radiosurgery
Microsurgical resection
- Extent of resection and the Simpson scale
- Simpson grading system
- Recurrence by extent of resection
- Goal of surgical resection
- Approach selection for CPA meningiomas
- Retrosigmoid craniotomy: sequence of steps
- Craniotomy and sinus exposure
- Brain relaxation before tumour dissection
- Devascularising the dural base
- Internal debulking of the tumour
- Arterial relationships in the cerebellopontine angle
- Displacement of the posterior fossa cranial nerves
- Facial nerve safety before entering the capsule
- Completing the resection
- Approach selection for intracanalicular meningiomas
- Middle fossa approach
- Translabyrinthine approach
Complications
- Reducing the incidence of complications
- Prevention of cranial nerve injury
- Intraoperative neuromonitoring
- Principles of intraoperative haemostasis
- Bleeding from the mastoid emissary vein
- Management of a venous sinus tear
- Haemostasis during tumour debulking
- Preserving posterior fossa vasculature
- Cerebellar oedema at dural opening
- Intraoperative obstructive hydrocephalus
- Keen's point and the last resort
- Preventing postoperative intracranial haemorrhage
- Postoperative neurological monitoring
- Management of posterior fossa haemorrhage
- Prevention of cerebrospinal fluid leak
- Routes of postoperative cerebrospinal fluid leak
- Initial management of a cerebrospinal fluid leak
- Escalation of cerebrospinal fluid leak management
- Lumbar drain protocol
- Meningitis after cerebrospinal fluid leak
Summary and references
- Key points
- References
- References (continued)
- References (continued)
- References (continued)
- Haynes-Glasscock-Shambaugh Surgery of the Ear, Seventh Edition
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