Introduction: Vein of Galen aneurysmal malformation (VGAM) is a rare and complex arteriovenous malformation of the brain, which is associated with poor prognosis. It is characterised by shunting of one or more arterial blood flow into an enlarged vein of Galen located under the cerebral hemispheres. In this case report, we aim to increase awareness on this rare but serious condition.
Case Report: A 31 year old healthy multipara was referred to our Foetal Medicine Unit for foetal hydrocephalus noted during a routine ultrasound scan at 28 weeks of pregnancy. Antenatally her pregnancy was uncomplicated, and she was booked at 7 weeks. Her pregnancy was dated by ultrasound scan at 12 weeks.
Our scan revealed increased biparietal diameter (BPD) and head circumference (HC), at 88 mm (corresponded to 35 weeks) and 293 mm (corresponded to 32 weeks), respectively. There was severe bilateral ventriculomegaly with a well circumscribed round mass located centrally at the base of the brain posteriorly. Colour doppler showed markedly increased vascularity of the mass with feeding vessels. A diagnosis of Vein of Galen Aneurysmal Malformation was made.
Cardiac scan showed increased cardio-thoracic ratio with mild tricuspid regurgitation, which indicates high output cardiac failure. There was reversed end diastolic flow (EDF) on the umbilical artery (UA) doppler, with a normal ductus venosus (DV) doppler. No other abnormalities were detected sonographically.
After a multi-disciplinary discussion involving the Consultant Neurosurgeon, the couple was counselled regarding the poor prognosis for the foetus. The couple opted for conservative management. She went into labour at 30 weeks and delivered a 1.4 kg baby with increased head circumference, who died 2 hours after birth.
Discussion: VGAM may cause hydrocephalus due to its location and mass effect, as well as bleeding and high output cardiac failure secondary to shunting of blood. Successful embolisation using interventional radiology have been reported internationally with promising results in selected cases. However, VGAM presenting during the neonatal period have been shown to have worse prognosis than those presenting later in childhood.
Conclusion: In this case, we concluded that the prognosis for this foetus was poor due to severe hydrocephalus with high risk of long term adverse neuro-developmental outcome of the VGAM. In addition, there was evidence of foetal compromise as seen by the reversed EDF of the UA doppler and high output cardiac failure at extreme prematurity.