Edward Fohrman shares his presentation about Neuroanesthesia for Cerebral Arteriovenous Malformations. Visit EdwardFohrman.com for more information about Edward and his industry insights.

1. Neuroanesthesia for Cerebral
Arteriovenous Malformations
Edward B. Fohrman, M.D.
Assistant Professor, Department of Anesthesiology
Northwestern University
Feinberg School of Medicine
Chicago, IL

2. Case Presentation
• 30 y/o male presents to the ER after waking up in
the morning with the taste of blood in his mouth,
noting that he bit his tongue sometime during the
night…
• PMH noncontributory, Neurologically intact
• What happened???
• What other work-up, if any, does the patient need?

3. XXXXXXX
MRI

4. Diagnosis
• New Onset Seizure Disorder
• 4 x 4cm Right parieto-temporal AVM (Spetzler
Martin Grade IV), with a nidus fed by branches
of the Right MCA and venous drainage into
multiple superficial and deep cortical veins…

5. • Congenital/Sporadic
• Incidence = 0.5%
• Venous dz w/ art. recruitment
• Arteries lack smooth m. layer
• “Arteriolized” Veins
• Absence of autoregulation in
AVM
• Shift of autoregulation in
surrounding brain tissue…
Lack of capillary bed (SHUNT)
↑Pressure, ↑Flow, ↓Resistance

6. Shift of Cerebral Autoregulation
normally 50 vs. 70 -150mmHg
RIGHTLEFT
Chronic HTN
Anemia
Sympathetic Stim.
TBI
Hypotension
Carotid Stenosis
AVM adjacent

7. Common Presentation of AVM’s
• Intracranial Hemorrhage (40-70%) Most Common
Intraparenchymal (60%)
SAH (30%) from AVM or Aneurysm (10-20%)
IVH (6%)
• Seizures (20-40%)
• Headaches (1-25%)
• Neurologic deficit (<10%, extremely rare)
RM Friedlander, NEJM 2007, 356:2704
J. Zhao et al. International Congress Series 1259, (2004)

8. • Progressive decrease in arterial pressure from the Circle
of Willis to the AVM nidus…
• Circulatory beds in parallel with the AVM, will be
perfused at lower than normal pressures even if CBF
remains relatively normal.
Hashimoto & Young Neurosurg Focus, 2001
‘Steal’ Is an Unestablished Mechanism for the Clinical
Presentation of Cerebral Arteriovenous Malformations
(Mast et al., Stroke. 1995;26:1215-1220.)
From the Departments of Neurology (H.M., J.P.M., R.S.M., R.M.L.), Anesthesiology (A.O., W.L.Y.), Neurological
Surgery (J.P.-S., B.M.S., W.L.Y.), and Radiology (J.P.-S., W.L.Y.), Columbia–Presbyterian Medical Center, New
York, NY.

9. Risk Factors for AVM Hemorrhage
• Presence of aneurysms (10-20%)
– (feeding artery, intranidal, venous)
• Prior hemorrhage
• Deep venous drainage (single draining vein or venous stenosis)
• Deep location (basal ganglia/thalamus, internal capsule, corpus callosum)
• Size? Unlike aneurysms, AVM size appears unrelated to rupture risk (?smaller
avm’s rupture more frequently?)
• Pregnancy???

10. Pregnancy and the risk of hemorrhage from
cerebral arteriovenous malformations
• Controversial…
• Retrospective review 451 women
• 17 pregnancies complicated by hemorrhage
• 3.5% Risk of bleed during pregnancy
• 25% Rebleed Rate during pregnancy vs. 6% in
general population
Horton et al., Neurosurgery. 1990 Dec;27(6):867-71

11. J Neurosurg 108:186–193, 2008

12. Spetzler–Martin Grading Scale for Cerebral
AVM’s
Feature Score
Maximum Diameter
< 3 cm 1
3-6 cm 2
>6 cm 3
Location
Noneloquent Cortex 0
Eloquent Cortex 1
Venous Drainage
Superficial only 0
Deep Venous Drainage
The Sum of the scores is equal to the grade (1-5)
1

13. Grade 1
Grade 2
Grade 3
Grade 4
Grade 5
J. Zhao et al. International Congress Series 1259, (2004)

14. Treatment Options for AVM’s
• Observation…
– Large AVM’s > 20ml nidus volume , S-M Grade 4 or 5
• Stereotactic Radiosurgery
– Small AVM’s <3cm, S-M Grade 1 or 2, eloquent locations
– Consider PreRTX Embo
• Embolization
– Complete treatment for smaller AVM’s in 10-30% (Vineula et al. J Nsurg, 1991)
– 1% mortality, 2-4% bleed, 2-5% neuro morbidity
– Adjuvant to decrease surgical bleeding and improve outcome
• (Demerrit et al. AJNR 16, 1995)
– Benefits of Staging the embolization
• Surgical Extirpation
– Primary Treatment for all SM Grade 1 & 2, but SM 3 eval. case by case
• Multidisciplinary Therapy
– SM 4 & 5 - surgery alone not recommended
A Randomized Trial of Unruptured Brain AVMs
(ARUBA)
• Currently underway - first trial randomizing patients with
nonhemorrhaged AVMs to invasive vs. conservative
management

15. Surgical Outcomes based on
Spetzler-Martin Grading
92-100%
95
%
65-85
%
70
%
55
%
Spetzler-Martin Grade

16. Treatment Plan
3-Stage
embolization of the
FEEDING arterial
vessels
Right Craniotomy
for AVM resection
Rt. 2mm Carotid Opth. An.
Rt. 3mm Ant. Choroidal An.

17. Cerebral Angiogram
WHY STAGE THE EMBOLIZATION?

18. Anesthetic Considerations
for Embolization of AVM’s
• Awake MAC vs. General
• Superselective “WADA” Testing
– (Amytal, Lidocaine)
• A-line, 2 large bore IV’s
• Prior to “Glue” injection w/ N-butyl-cyanoacrylate
(NBCA) or Onyx
– Deliberate Hypotension
– Adenosine
– Valsalva?

19. Major Disasters in Neuro IR
• Hemorrhage
– If hemorrhagic rather than ischemic, reverse heparin
with protamine
– Prepare for CT and potential transport to OR
• Ischemia - Inadvertant vascular occlusion
– Deliberate HTN should NOT be avoided due to fear of
rupturing the AVM

20. Anesthetic Induction
Considerations
• Premed
• Monitoring
• Induction drugs
• Is hemorrhage a risk?
• Associated Aneurysm!?!?!

21. Rt. Parietotemporal AVM

22. Anesthetic Maintenance Considerations
• Anesthesia recipe?
• Blood pressure management?
– Target?
– Treating hypotension?
• Volume replacement
• Vasoactive agents
• “Lighten” anesthesia

23. Neuroprotection
• Perfusion
• Hgb/O2 delivery
• Glucose control
• Na balance
• Temperature
• Clotting homeostasis
• Burst suppression

25. Intraop ICG Angio
• Near infra-red spectroscopy
– Previously used extensively in Retina surgery, Cardiac output, Liver perfusion and
function - Hepatic elimination (plasma half-life 3-4 mins)
• 0.2 – 0.5 mg/kg for video-angiography
• Max daily dose 5 mg/kg
• Case reports of anaphylaxis? (<1%)

26. • 12 hours into case, heavy blood loss began
• Massive Transfusion Protocol activated
• Surgeons work to control bleeding and repair
“EN PASSAGE” vessels…
• 20 hour operation
• Transport to neuroangio to look for residual AVM?
EBL >6000 ml

27. Post-resection Angio

28. Postoperative complications of AVM’s
• Bleeding
• Edema
• Normal Perfusion Pressure Breakthrough
• Occlusive Hyperemia

29. Normal Perfusion Pressure Breakthrough
(NPPB)
• The clinical syndrome of
– cerebral hyperperfusion with normal CPP
• The smaller vessels surrounding the AVM are not
accustomed to the higher pressure-flow state and
autoregulation is exceeded, resulting in severe brain
swelling, edema, and hemorrhage (Spetzler et al. Clin Nsurg 25,
1978)

30. ICU Considerations
• Hypervigilant BP Control!
• Osmotic diuresis
– mannitol/lasix
• Burst suppression
– Which drug?
• ICP Monitoring?
– Hyperventilation

31. Follow-up
• The patient was noted to have postoperative
– Left hemineglect
– mild Left hemiparesis.
• Upon discharge home, the patient’s hemineglect
was completely improved and he had only a small
degree of residual LUE weakness.
• Dr. Batjer reports seeing him in the office recently
and he is doing well!

32. Thank You