Arteriovenous Malformation (AVM) of Brain

Arteriovenous Malformation (AVM) of Brain
AVM
Cerebral AVM
Vascular Malformation

1. Arterio -Venous Malformations (AVM) of Brain Dhaval Shukla Additional Professor of Neurosurgery NIMHANS, Bangalore

2. Normal Blood Vessels Abnormal Connection of Blood Vessels AVM

3. Cause of AVM Not known Usually congenital Not hereditary Most AVMs do not grow or change in size Blood vessels may increase in diameter AVMs shrink due to clots in parts of an AVM AVMs may enlarge due to redirection of blood flow

4. Epidemiology Less than one percent of the general population One in 200–500 people may have an AVM More common in males than females

5. Sites

6. Symptoms Symptoms may vary with location More than 50 % present with brain hemorrhage 20% - 25% with seizures Localized headache 15% may have difficulty with movement, speech and vision

7. Brain hemorrhage Abnormal and “weakened” blood vessels over time eventually burst from the high pressure of blood flow from the arteries 1–3 % chance per year of bleeding Risk of bleeding = 105 – age (in years)

8. Brain hemorrhage 10–15% risk of death Loss of normal function T emporary Permanent: 20–30% Brain damage depends on Amount of blood Site of bleed

9. Symptoms of hemorrhage

10. Rebleeding risk More during first year after initial bleeding 6% to 18% Higher in the first year after the second bleed 25% Higher risk of bleeding in ages 11 – 35 years

11. Diagnosis Computed tomography (CT) Hemorrhage Magnetic resonance imaging (MRI) Location and size

12. CT scans showing hemorrhage due to AVM

13. MRI of AVM

14. Diagnosis Cerebral angiogram (DSA) Required for treatment Insertion of a catheter (small tube) through an artery in leg to each vessels going to brain Injection of contrast material (dye) Taking pictures of all blood vessels of brain

15. Treatment Bleed Easily accessible Not too large

16. Medical Therapy Avoid Any activities that may excessively elevate blood pressure Blood thinning drugs like warfarin Regular checkups with a neurologist Antiepileptic drugs

17. Surgery Indications Bleeding Easily accessible Small or medium

18. Stereotactic radiosurgery (Gamma Knife) Indications Small Difficult to reach by surgery Mechanism Produce direct damage to the vessels that will cause a scar and allow the AVM to “clot off” Takes 2 years to cure AVM

19. Endovascular treatment Indications Usually for a part of AVM Rest of AVM requires treatment either with surgery or Gamma Knife Occasionally for small AVM Mechanism Blocking off abnormal blood vessels to stop blood flowing to AVM Liquid tissue adhesives (glues) Coils Particles and other materials used

20. Endovascular treatment

21. Outcome – Surgery Small AVMs Cure: 94 to 100% Morbidity and mortality: <10% Bleeding Infection Paralysis or loss of function (temporary or permanent) Convulsions (controllable or uncontrollable) Coma (reversible or irreversible) Death Seizure-free: 81% Large AVMs Morbidity and mortality: 25%

22. Outcome – Gamma Knife Cure: 61% to 87% (after 2 years) Morbidity (during 2years): 1 to 36% Mortality (during 2years): 0 to 9% Seizure-free: 43%

23. Outcome – Endovascular treatment Cure: 5 to 40% Morbidity rates: 8% -10% Same as for surgery Mortality rate: 1% Seizure-free: 50%

24. Conclusion AVMs are difficult to treat and treatment decision should be individualized If AVM has not ruptured (never bled) there is no need of specific treatment. Patient requires only symptomatic treatment Whenever possible microsurgery is the best option Gamma Knife is an optional treatment for inaccessible AVM Endovascular treatment is not effective as stand alone for most cases Medium size AVMs require multimodal treatment Very large AVMs should not be treated