VGM is a rare type of vascular malformation of the brain that develops before birth, perhaps as early as 11 to 14 weeks of gestation. VGM occurs when there is an abnormal connection between arteries and veins. Normally, these arteries and veins are connected by capillaries, which slow blood flow through the brain, allowing for the exchange of oxygen and nutrients in brain tissue. Because a VGM does not have capillaries, the blood flow is very fast, making the heart work harder.
This can result in heart failure, which is the most common problem in newborns with this disorder. If left untreated, a VGM may hemorrhage or may cause extra spinal fluid to accumulate leading to hydrocephalus and large head size. Because blood is flowing too fast and is not delivering nutrients to the brain tissue effectively, brain growth and development may be affected. Children with VGM may have problems with mental development, resulting in retardation or even death.
Often suspected by prenatal ultrasound, diagnosis is confirmed with magnetic resonance imaging (MRI) scan.
Endovascular embolization - During this procedure, we pass a catheter through the groin up into the arteries in the brain that lead to the VGM and inject a material into these arteries. This injection shuts off that artery and reduces the flow of blood through the VGM.