Vein of Galen aneurysm

Other Names: Ectasia or varix of the vein of Galen; Galenic arteriovenous malformation; Vein of Galen aneurysm malformation; VGAM; Galen vein aneurysm

Vein of Galen aneurysm is a rare form of arteriovenous malformation in which the embryonic precursor to the vein of Galen, a vein at the base of the brain, dilates causing too much blood to rush to the heart. This can lead to rapid heart failure.

3D reconstruction of CTA showing vein of Galen malformation.

Cause

Vein of Galen aneurysm originates during a baby's early prenatal development (usually during weeks 6-11). It involves a large vein at the base of the brain that is formed early in gestation and is normally replaced by the vein of Galen. In children with this condition, high-pressure, high-speed blood from the arteries flows directly into this precursor vein, preventing a true vein of Galen from forming.

Vein of Galen aneurysm has been associated with capillary malformation-arteriovenous malformation (CM-AVM) syndrome, a newly recognized autosomal dominant disorder caused by mutations in the RASA1 gene in a small number of families.

Signs and symptoms

Neonates with the choroidal type of VGAM typically develop severe congestive heart failure, while those with the mural type tend to present with hydrocephalus, mild heart failure, or seizures. Focal neurological deficits, headaches, subarachnoid haemorrhages, mental developmental delay are more frequently observed in older children with VGAMs . Symptoms and signs of VGADs may include intracerebral haemorrhage, intraventricular haemorrhage, hydrocephalus, gaze palsy, and diplopia.

For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. 80%-99% of people have these symptoms

• Abnormality of the cerebral vasculature(Abnormality of the cerebral blood vessels)

30%-79% of people have these symptoms

• Dilatation(Wider than typical opening or gap)
• Peripheral arteriovenous fistula

Diagnosis

Testing for a malformed vein of Galen is indicated when a patient has heart failure which has no obvious cause. Diagnosis is generally achieved by signs such as cranial bruits and symptoms such as expanded facial veins. The vein of Galen can be visualized using ultrasound or Doppler. A malformed Great Cerebral Vein will be noticeably enlarged. Ultrasound is a particularly useful tool for vein of Galen malformations because so many cases occur in infancy and ultrasound can make diagnoses prenatally. Many cases are diagnosed only during autopsy as congestive heart failure occurs very early.

Treatment

Treatment is aimed at decreasing the blood flow through the malformation while maximizing the blood supply to the brain. Minimally invasive surgical techniques are preferred, such as endovascular embolization. Therapeutic options available for a VGAM include no treatment, open surgery, endovascular treatment, and stereotactic radiosurgery. Treatment of the given patient should be individualised with consideration of their age, the clinical manifestation of the lesion, and its angioarchitecture. Endovascular treatments include transarterial, transvenous, and trans-torcular routes. In the neonatal period, a trans-umbilical route allows both transarterial and transvenous approaches .Among these, it has been reported that transarterial embolisation provides the better outcome. In general, liquid glue and coils are used in transarterial embolisation and coils in transvenous embolisation. If one session of embolisation is not enough, a subsequent intervention can be performed within a few days leaving the femoral vascular sheath in place.

Prognosis

Because of advances made with endovascular surgery, the prognosis of a patient with a VGAM has drastically improved, with this form of intervention now considered the treatment of choice due to its limited invasiveness . However, the prognosis may largely depend upon the degree of arteriovenous shunting at the time of initial presentation.

NIH genetic and rare disease info

• NIH info on Vein of Galen aneurysm

Vein of Galen aneurysm is a rare disease.

Vein of Galen aneurysm Resources
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