Posterior fossa AVMs; endovascular management challenges

Hany A. Fikry Eldawoody1, 2,

Mohamed Mostafa Aziz3

Wasem Aziz4

Department of Neurosurgery Mansoura University, Egypt 1

Department of Neurosurgery, Prince Mohamed Bin Abdel Aziz Hospital, Riyadh, Saudi Arabia2

Department of Neurosurgery, Ain Shams University, Egypt3

Department of Neurosurgery, Alexandria University, Egypt4

SANS 2016 , Ritz Carlton Hotel, Riyadh, SA,1-3/3/2016

• Posterior fossa arteriovenous malformations (AVMs)are complex neurovascular lesions

• Nearby eloquent areas

• Relatively infrequent < 15% of all AVMs

• More aggressive natural history

Background

Background“Cerebral arteriovenous malformation (AVM)”

• Etiology：Abnormality of primordial angiogenesis

- Agenesis of capillary system

- Retention of primordial vascular connections

Epidemiology

• 1 /100,000 person/year (all detected)

• caused 2% of hemorrhagic stroke

• 2～4% annual rate of hemorrhage

• Enlargement/shrinkage rate: unknown

Global consensus To obtain

Better outcome..

Maximize Team Effort:

Microsurgery

Embolization

Radiosurgery

• Between January 2012 to August 2015.

• 20 patients’ data with posterior fossa AVMs treated withendovascular techniques, radiosurgery and/or surgery wereanalyzed.

Patients and methods

Master tableAge Sex Presentation GCS Site

Size

cmSMG Feeder Drainer Procedure

Immediate

Outcome

Oblteration

%ageComplications GOS

Follow up

Radiology

55 m 4th vent Hage 15 Rt Cerebellar 3 2Rt SCA, Rt

PICA, PICA AnDeep AN Coiling FC, Intact NO NO 5 No

16 fIVH, Cerebellar

Hage12 Rt Cerebellar 3 2 Rt SCA Deep Evacuation+onyx emb FC, Intact 90% no 5 -

44 m IVH 15 Lt cerebellar 1.5 2 Lt SCA Deep Onyx embolization 3, ataxia 100% SCA infarction 4 100%

52 m IVH, HCP Lt cerebellar 3 2 Lt SCA Deep 2 sessions onyx emb FC, Intact 95% NO 5 95%

56 mDizziness,

Vertigo15 Lt CPA 3 3

Lt PICA, AICA,

SCADeep 2 sessions onyx emb, GK 3, ataxia < 50% SCA infarction 4 < 50%

45 fCerebellar Hage,

IVH, HCP

Vermian, Lt

Cerebellar4 3 Lt AICA, Lt SCA Deep Onyx embolization, GK 3, ataxia 80% cerebellar signs 4 Recanalization

50 m Recurrent SAH Lt CPA 4 3 Lt AICA, PICA Deep Onyx embolization Died 75% Died 1 -

30 f HCP, Dist. Consc 10BS & Bilat

Cerebellar6 5

Bilat AICA,

PICA, SCADeep

VP Shunt & 3 sessions onyx

emb

Improved

gradually50% NO 5 50%

28 f, P.cerebellar Hage,

Ataxia13 Lt cerebellar 2.5 2 Lt SCA, PICA

Transverse

SigmoidEvacuation+onyx emb 3, ataxia 100% No 5 100%

65 f IVH 9 Rt Cerebellar 3 2Rt PICA, PICA

AnDeep

Ventriculostomy, Surgical

excision1 100% No 1 -

40 m IVH 9 vermian 1.5 2 Rt SCA transverse surgical excisionimproved

gradually100% No 5 100%

35 f, P.cerebellar hage,

IVH10 vermian 4.5 4

Lt PICA, AICA,

SCADeep

Evacuation+onyx emb 2

sessions

improved

gradually90% No 4 90%

14 f Incidental 15 Rt Cerebellar 2 1 Superficial Embolization & excision FC, Intact 100% No 5 100%

52 m Headache 15 Rt Cerebellar 3.2 2 Superficial 2 sessions onyx emb FC, Intact 70% No 5 70%

30 f Brain stem Hge Brain stem 1.2 3 Deep surgical excisionImproved

gradually100% NO 4 100%

21 f Headache 15 Lt cerebellar 5.6 4 Deep 7 sessions onyx FC, Intact 75% NO 5 75%

24 f

recurrent

cerebllar

hematoma

15 Rt Cerebellar 2.5 1Rt. SCA, AICA,

PICASuperficial

partial evacuation of the

hematoma and biopsy then

one session onyx 2 ampouls

FC, Intact 50%P SAH, resolved

completely5 50%

55 mRt. trigeminal

neuralgia15 Rt Cerebellar 4 2 Rt. SCA Superficial

one session onyx, 3

ampoules

FC, transient Rt.

hemihypothesia 60% No 5

60% referred to

GNRS

1.3 m

venous

hypertention,

large head, sinus

pericranii

15 superior vermis 4 3bilateral SCA, Lt.

PICASuperficial

one session onyx, 3

ampoulesFC, Intact 75%

temporary

repeated

vomiting

575% for another

session

22 m

cerebellar

hematoma,

disturbed

conscious level

9upper cerebellar

surface1.5 1

left pica, Bilateral

SCASuperficial surgical excision FC, Intact total No 5 Total

Results

20%

45%5%

10%

15%5%

TREATMENT MODALITY

surgery only

onyx only

coiling of associated AN

onyx then surgery

onyx then GN

NBCA then GN

Results©

2

21

3

DIFFICULTIES IN ENDOVASCULAR TREATMENT

catheter navigation in SCA

catheter navigations in AICA

catheter navigations in PICA

identifications of onyx inWA

Challengeschallenges How to solve

Proximal access in the VA -5F guiding with soft tip- Transbrachial artery in right sided VA access

Navigation Detachable tip microcatheterTry smaller .007 hybrid

MCR Catheter stuck in the nidus Detachable tip microcatheter

Visualization of onyx flow Shack well before useUse flat panel angio machine

Blank map

Proximal Reflux of LE agent Allowed

Not well definedPICA after second lobe

As distal as possible; Nidal wedgingDetachable tip microcatheter – 3rd marker

Nondetachable tip MCR 0.5-1 cmIn cm from brain stem ?! Working on

Extravasation Not under pressureDrop like accumulation

Better user Phil

Example of tortuousity (AICA)

Example of tortuousity (SCA)

Example of post fossa AVM total occlusion in two session using onyx

A 28 years female patient

presented during the second

month of pregnancy with acute

hemiataxia. CT brain showed Left

cerebellar hematoma. DSA

showed Lt hemispheric

cerebellar AVM supplied by

hemispheric branches of

Posterior Inferior Cerebellar

Artery (PICA) and small branch

from the superior cerebellar

artery. Onyx embolization was

done and eventual near complete

obliteration was achieved.

Patient has marked symptomatic

improvement 6 months later.

Example of post fossa AVM near total occlusion in one session using onyx

Example of subtotal occlusion of posterior fossa AVM using onyx in one session

Example of subtotal occlusion of posterior fossa AVM using onyx in one session ©

• The task is difficult but not (mission impossible).

• Careful study of angiogram & use the best WA andbest easy access main feeder first.

• Precise controlled intra-nidal injection to be stronglyconsidered.

• Consider the use of detachable tip MCR catheter.

• The controllability & diffusability of the LE Agent(phil>onyx>nBCA).

conclusion

• Multiple sessions on intervals is generally better inmultifeeder AVM.

• Give the patient the best chance by Using all tools;donot be dogmatic (only endovascular!!!!)

Conclusion©

Thanks