What Is An Arteriovenous Malformation?
An Arteriovenous Malformation (AVM) is an abnormal tangle of blood vessels in the brain or spine. Normally blood flows through arteries that branch and get smaller until they become a capillary. Blood travels from the capillary bed back to the heart through veins. In an AVM, arteries connect directly to veins without a capillary bed in between causing the vessels to stretch, enlarge, and sometimes rupture.
This creates a problem called a high-pressure shunt or fistula. Veins are not able to handle the pressure of the blood coming directly from the arteries. The veins stretch and enlarge as they try to accept the extra blood. The weakened blood vessels can rupture and bleed and are also more likely to develop aneurysms. The surrounding normal tissues may be damaged as the AVM “steals” blood from those areas. There are four types of AVMs:
Arteriovenous malformation – abnormal tangle of blood vessels where arteries shunt directly into veins with no intervening capillary bed; high pressure.
Cavernoma– abnormal cluster of enlarged capillaries with no significant feeding arteries or veins; low pressure.
Venous malformation – abnormal cluster of enlarged veins resembling the spokes of a wheel with no feeding arteries; low pressure, rarely bleed and usually not treated.
Capillary telangiectasia – abnormal capillaries with enlarged areas (similar to cavernoma); very low pressure.
Symptoms include stroke, seizures, headache, and other problems. Surgery, embolization, and Radiosurgery can be used to treat an AVM.
Our surgeons at Salus treat Arteriovenous malformation by performing the following procedures:
ENDOVASCULAR THERAPY
Endovascular treatment uses small catheters inserted into your blood vessels to deliver glue or other obstructive materials into the AVM so that blood no longer flows through the malformation.
The advantage of this treatment is it's less invasive than surgery and can be used to treat deep or inoperable AVMs. Disadvantages include risk of embolic stroke from the catheter and rebleeding since the AVM is not completely obliterated. Multiple treatments may be necessary.
CRANIOTOMY SURGERY
Using general anesthesia, a surgical opening is made in the skull, called a Craniotomy. The type of craniotomy performed depends on the size and location of the AVM. The option of surgery also depends on the general health of the patient. The advantage of surgical treatment is that a cure is immediate if all the AVM is removed. Disadvantages include risk of bleeding, damage to nearby brain tissue, and stroke to other areas of the brain once removed.