Arteriovenous malformation or AVM is an abnormal connection between veins and arteries, usually congenital. This pathology is widely known because of its occurrence in the central nervous system, but can appear in any location.
Treatment is offered is to try to prevent bleeding from the AVM. Bleeding may injure the surrounding brain resulting in a stroke, with possible permanent disability or even death. The risk of bleeding is 4% per year, which means that 4 out of every 100 people with an AVM will have a bleed (haemorrhage) during any one year. AVM’s may also produce headaches, seizures and progressive paralysis, and the treatment may alleviate these symptoms. Embolisation has been used to treat AVM since the early 1980’s.
This procedure involves the injection of liquid adhesive material into the AVM in order to block it off. For this purpose, a small catheter is passed through a groin vessel all the way up into the blood vessels supplying the AVM. The injected glue liquid rapidly hardens as it is injected into the AVM. The result is that the flow of blood through the AVM is blocked off. When there is no longer any blood passing through an AVM, there is no further risk of bleeding. For the larger size AVM embolisation is often done in stages so that each time a portion of the AVM is blocked off. If an AVM is not completely closed off there is still a risk of bleeding.