The Vein of Galen is a large blood vessel located at the base of the brain underneath the hemispheres. Its main job is to drain the anterior and central parts of the cerebellum into sinuses located in the posterior fossa. Vein of Galen malformations involve missing capillaries which result in a direct link between a cerebral artery and vein. This does not allow the blood to slow down and drop off its oxygen and other nutrients as it normally would. Instead the blood flows rapidly from artery to vein and rapidly moves to the heart which cannot withstand this rush of blood. These malformations almost always cause congestive heart failure. Vein of Galen malformations are congenital defects and are sometimes seen on ultrasounds. Babies born with these defects can also have hydrocephaly because the enlarged vessel blocks the flow of CSF from the brain. Children with V of G malformations can also experience seizures and headaches, are slower learners and show signs of respiratory distress and cyanosis at birth. Babies who show CHF as the predominant symptom often die before birth or shortly thereafter. Shunting can markedly reduce the symptoms of macrocephaly and can often greatly, if not completely improve the life of the child. The best treatement for this disorder is by embolization of the affected vessel. The blood supply to the vessel is re-routed by the placement of a “man-made” embolis. This blocking action allows the blood flow to the heart to return to normal and often times the symptoms of the malformation dissipate. This procedure can allow the patient to lead a normal and active life.
http://www.childrenshospital.org/clinicalservices/Site2162/mainpageS2162P16.html
http://emedicine.medscape.com/article/1179888-overview
http://www.veinofgalen.co.uk/vog.htm