Arteriovenous Malformation (AVM) Treatment
Blood vessels that develop abnormally are called vascular malformations, and when these malformations involve both the arteries and veins they are called arteriovenous malformations (AVMs). Some AVMs prevent oxygenated blood from filling capillaries, the tiny blood vessels that connect the arteries and veins, and in a potentially dangerous form of AVM blood travels directly from the arteries into the veins without ever reaching the capillary system, depriving tissues not supplied by capillaries of oxygen. If you have been diagnosed with an AVM, your physician may refer you to an interventional radiologist for a procedure called embolization.
What is embolization?
Embolization is a minimally invasive procedure in which we occlude, or block, the blood vessels that supply the AVM. Using imaging guidance the interventional radiologist passes a catheter from a small opening in the groin to the malformation, injects a contrast dye to highlight the blood vessels and malformation, and blocks the artery with a synthetic material called an “embolic agent”. By stopping the flow of blood to and through the malformation, your doctor cab shrink it, minimize the risk of hemorrhage, and stop symptoms from progressing.
How do I get ready for the procedure?
On the night before the procedure eat a light meal, then do not eat or drink anything after midnight. We will provide you with more detailed information about which medications you may take in days before and on the morning of the procedure. Plan to have someone accompany you home after the procedure. Occasionally, patients are admitted overnight for additional monitoring. Bring what you need for an overnight stay.
What will happen during the procedure?
After you arrive at the interventional radiology (IR) suite and change into a gown, you will lie face up on the procedure table. To relax you and block any pain we will intravenously give you a combination of medicines called “conscious sedation.” Using X-ray and/or ultrasound image guidance, we will insert a long, very thin tube called a catheter through a small incision into a large blood vessel in the groin, arm, or neck. The doctor will inject a contrast dye through the catheter to highlight the malformation and the blood vessels that supply it on the X-ray, and will then deliver a synthetic material called an “embolic agent” to block the artery. The embolic agent used most often is a metallic coil. Once it is confirmed that there is no flow going to the AVM, the catheter is removed, and a band-aid is placed at the groin. The entire procedure takes about an hour.
Are there any risks?
In general, interventional therapy is safe and commonly associated with only minor side effects, including low-grade fever, nausea, and pain. The most serious risk is that an interventional procedure may cause hemorrhage, or bleeding.
After the procedure
Most people remain in the interventional radiology suite for several hours of rest and observation following embolization, and are then able to go home. Your physician may prescribe pain medication for you. We will give you additional instructions before you go home from the interventional radiology suite.