arterio-venous malformations of the brain
TRANSCRIPT
A SMALL PRESENTATION TO 5TH YEAR MEDICAL STUDENTS AT THE UNIVERSITY OF JORDAN, AND TO THE 4TH YEAR STUDENTS AT THE HASHIMEYAH UNIVERSITY
WALID S. MAANI FRCSEd
PROFESSOR OF NEUROSURGERY
JORDAN UNIVERSITY MEDICAL SCHOOL AND HOSPITAL
ARTERIO-VENOUS MALFORMATION OF
THE BRAIN (AVM)
WHAT IS AN AVM?
• It is an abnormal connection between arteries and veins.
• It has a feeding artery or arteries
• A nidus
• A draining vein or veins
WHY DO AVMS OCCUR?
No body knows but they are
congenital and one is borne with
them, and they tend to grow by age.
WHEN DO THEY PRESENT?
They usually present early in life, around the
age of 10, but they can occur in older
patients up to 40 years of age. Once they
reach that age they mostly become stable.
HOW DO THEY PRESENT?
• They may be found incidentally when performing brain imaging
for other reasons.
• They may produce symptoms by “shunting” blood from its
normal course through capillaries.
• May cause pressure on the brain
• May induce epilepsy
• May rupture and produce intra cranial hemorrhage.
UNRUPTURED AVMS
• Being on the surface of the brain the may cause epilepsy.
• Shunting blood may lead to ischemia of certain part of the brain
and therefore brain damage.
• The abnormal blood vessels, being weak may develop
aneurysms.
• If large, they may compress the brain by sheer size and produce
neurological symptoms.
RUPTURED AVMS
• Rupture causes subarachnoid hemorrhage (SAH)
• It manifests it self by:
• Sudden headache
• Vomiting
• Deterioration of the level of consciousness
• Epilepsy
• Neurological manifestations
• Neck rigidity
DIAGNOSIS
In addition to clinical suspicion, the following is performed:
CEREBRAL ANGIOGRAPHY
CT ANGIOGRAPHY
MAGNETIC RESONANCE ARTERIOGRAPHY (MRA)
•
WHAT DO WE NEED FROM ANGIOGRAPHY?
• Demonstrating the AVM”s location and size
• Showing the feeding artery
• Showing the draining veins
TREATMENT
Factors influencing choice of treatment:
• The location of the AVM
• The size of the AVM
• Did the AVM bleed or not?
TREATMENT
Medical treatment is only reserved for
associated symptoms like treating seizures or
relieving headache.
TREATMENT
Definitive treatment is one of three:
• Surgical removal (resection)
• Occlusion by endovascular techniques
• Destruction by radiation (Gamma Knife)
SURGICAL REMOVAL
Usually indicated for superficial AVMs and those
which can be removed without harming the brain.
The feeding artery is occluded and the nidus
removed.
ENDOVASCULAR
• Could be used as an adjuvant to surgical resection; to
reduce the size of the AVM before surgery.
• Or, could be the sole treatment for deeply seated
AVMs, in which surgery is deemed harmful or
dangerous.
• Usually done by insetting beads or other material into
the lumen of the abnormality to occlude blood flow.
GAMMA KNIFE
• It is irradiation delivered by stereotactic procedure,
targeted at the AVMN.
• It usually require certain indications or prerequisites
regarding size and location.
• It certainly could be performed in emergency after
bleeding, because the irradiation need perhaps 2 years
to completely fibrose the AVM