Supratentorial and infratentorial cavernous malformation

Youmans Chapter 394Gregory P. LekovicRandall W. porterRobert F.Spetzler

Outline

• Treatment• Opearative procedure• Surgical approaches

Treatment• Observation• Radiation therapy• Surgical indication• Contraindication

Observation• For pt whose symptoms resolve completely after an

acute hemorrhagic event• For pt with incidentally discover lesion(extremely low for

bleeding and chance for seizure 2-3 % per year)• observation and repeat imaging• Not restrict activity• Anticoagulant not contraindication• Reassure

Radiation therapy• Radiation therapy or stereotactic irradiation has not

been to confer a protective benefit from hemorrhage in CM

• Neurological deficit in eloquent area • Not recommend in deep-seated CM

Surgical indication• CM located anywhere in the ventricular system• CM of the thalamus or basal ganglia or deep seated

lesion– Acute hemorrhage : mass effect– Intralesional hemorrhage :mass effect

• Posterior fossa lesion outside brainstem– Acute hemorrhage : mass effect– Rupture multiple time– Expansion lesion– Intralesional hemorrhage :mass effect

• Refractory epilepsy

Contraindication• Severe medical problem• Single hemorrhage episode from brainstem CM in an

unfavorable location(far from pia surface)• Multiple CMs,unless an individual focus can be identified• Unexpect bleeding in posterior fossa lesion

– Bleeding– Significant change in neuromonitoring

Operative procedure• Goal of surgery and patient counseling• Preoperative imaging• Intraoperative monitoring• Surgical technique• Role of intraoperative MRI• Postoperative management

Goal of surgery and patient counseling

• Posterior fossa or deep-seated lesion– Extirpate with minimizing the amount of normal eloquent– Preserve venous anomaly

• Superficial supratentorial CM – Resect completely with minimal morbidity and excellent outcome

• No attempt to resect hemosiderin-laden brain• Patient educated : their deficit are likely to worsen after

surgery but will typically improve with time

Goal of surgery and patient counseling

• Best surgical method : two point method– One point center– Second is placed where the lesion near pia surface

Preoperative imaging• MRI imaging : pathognomonic• Angiography is not indicated

Intraoperative monitoring• SSEP, electroencephalography• Brainstem : motor evoke potential and brainstem

auditory evoked potential(BEAR)

Surgical technique• Opening by using hemosiderin staining or a bulge in the

brainstem as guide• Framless stereotactic guide• Exophytic lesion : mulberry• Mindful of the ubiquitous venous anomaly

– Large : venous infarction– Small : coagulate and transect

Role of intraoperative MRI• For complete resection• Or Frameless stereotaxy

Postoperative management• Superficial supratentorial lesion : similar to patient for

undergoing for tumour in same location• Brainstem

– good cough and gag reflex extubate– Evaluate post operative swallowing– Minimal : short-term tracheostomy or feeding tube

• Patient stable : MRI POD 1• Follow up imagine annually for the first few years to

monitor for progression or recurrence

Surgical approaches• Midline suboccipital approaches• Orbitozygomatic approach• Retrosigmoid approach• Far lateral approach• Supracerebellar Infratentorial approach • Interhemispheric Transcallosal approach

Midline suboccipital approach

Midline suboccipital approach• For

– Cerebellar– posterior cervicomedullary junction– midline of floor of the 4th ventricle

• Position : prone, neck flex• Incision : midline incision from C3 to inion• Fascia : Y-shape cuff• Dura : Y-shape• Suboccipital craniotomy

Orbitozygomatic approach

Orbitozygomatic approach• For

– Anterior and lateral midbrain– Interpeduncular region– Rostal pons– Pontomesencephalic junction– Optic chiasm– Hypothalamus

• Position : supine with head rotate 30-60 degree,slight extension neck

• Incision : root of zygoma anterior to tragus 1 cm to the midline or contralateral midline

Orbitozygomatic approach• Pterional craniotomy• Orbitozygomatic osteotomy

– Root of zygoma– Temporal process of zygomatic bone– Inferior orbital fissure to second cut– Orbital surface of frontal bone to superior orbital fissure – Inferior orbital fissure across greater wing to posterior orbit– Fifth cut to superior orbital fissure

• Dura : medial superior orbital margin to temporal tip

Retrosigmoid approach

Retrosigmoid approach• For

– Posterolateral pons– Lateral middle cerebellar peduncle– Superior lateral medulla– Cerebellopontine angle

• Position : lateral decubitus position• Incision : above auricle and curves behind the ear• Craniotomy : beware transverse sinus : line from the

root of zygoma to inion• Dura : curvilinear base on transverse sigmoid junction

Far lateral approach

Far lateral approach(transcondylar approach)

• For– Vertebrobasilar junction– Inferolateral pons– Anterolateral medulla– Upper cervical spinal cord

• Position : Modified park bench position• Incision : hockey-stick (midline at C2, superior and curve anterior

and lateral to mastoid tip)• Clivus perpendicular to the floor

– Flexion in AP until the chin is one FB from the clavicle– Rotation 45 contralateral to lesion side– Lateral flexion 30 to the floor– Slight distraction

Far lateral approach(transcondylar approach)

Far lateral approach(transcondylar approach)

• Posterior arch of C1 was removed• Lateral suboccipital craniotomy• Can access

– C1 and C2 rootlet– cerebellum; lower pons– cranial nerves IX, X, XI, and XII– vertebral arteries– ipsilateral posterior inferior cerebellar artery

Supracerebellar infratentorial approach

Supracerebellar infratentorial approach

• For– midline tectum and pineal region

• Position : Prone, neck flex• Craniotomy

– extend above and below the transverse sinus to expose the junction of the tranverse sinus and torcular

– Single burr hole lateral to SSS

• Dura : v shaped

Interhemispheric transcallosal approach

• For– Deep-seated supratentorial lesions : thalamus, lateral ventricle,

third ventricle, and corpus callosum

• Approaching the lesion from the contralateral side• Position : supine• Incision : linear incision oriented in the coronal plane• Craniotomy extend contralateral 1 cm