Cerebral Arterio Venous Malformations (AVM)

In normal vascular anatomy, blood flows through a bed of tiny capillaries to reduce pressure before entering the vein. Arterio Venous Malformation (AVM) is an abnormal circulatory pattern where an artery connects directly to a vein, some sort of a "short circuit" between the arteries (which carry blood from the heart to tissues) and veins (which carry blood from tissues back to the heart).

Normal and Abnormal Capillary Beds

Normally the connection between arteries and veins is through a network of smaller vessels called capillaries, which slow the blood down and permit the exchange of food, oxygen and nutrients into the tissues.

In an AVM, when the arteries and veins have direct connections to each other which bypasses the capillary network, the veins get exposed to the greater, fluctuating pressure of the arteries. Over time, this turbulent blood flow weakens the walls of the vein and which can burst.

Arterio Venous Malformation (AVM) Nidus

This network of abnormal connections represents the "nidus". Cerebral arteriovenous malformation (AVM) presents later in childhood or, more frequently, in adults in the second to third decade of life.

Cerebral (IntraCranial) AVMs present with seizures, hemorrhage, progressive neurological dysfunction or headaches. However, in many occasions, these lesions are found incidentally during an MRI or CT scan of the brain obtained for other reason.

Intracranial AVMs can be difficult to treat and often require a multidisciplinary approach to therapy. Embolization is curently a physicians' first choice when trying to manage such conditions.

Embolization for arteriovenous malformation may be done as the sole form of treatment or in preparation for microsurgical resection or radiation therapy.

For patients with cerebral AVMs that cannot be cured due to the size or location of their lesion, palliative embolization can improve the patient's quality of life and diminish symptoms such as headaches, seizures or other problems.