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Radiology
Embolisation of a vein of Galen anerysmal
malformation.
The parents of a nine-month-old boy came for consultation for prominent veins on the face and progressive increase in the size of the boy's head. He used to sweat profusely during breast feeding.
On examination, he was fairly nourished, conscious and stable. Pulse was 100/min and respiration normal. There was no neurological deficit. Developmental milestones were within normal limits. He had prominent veins over the face; his head being a bit large for the age. 2D echo of the heart was normal. A CT scan of the brain showed a vein of Galen aneurysmal malformation.
An MRI confirmed this. The brain had no abnormalities in white matter development. The prominent artery supplying the malformation was the posterior choroidal artery. The ventricles were dilated and there was obvious cerebellar tonsillar herniation due to venous hypertension
The left vertebral angiogram showed a high flow vein of Galen malformation supplied by two choroidal vessels from the right posterior cerebral artery. Neither of the posterior cerebral arteries was opacified due to high flow through the fistula
A microcatheter over a microwire was navigated to the site of fistula. Selective injection opacified the feeding artery and mural fistula. Embolization was carried out with pure glue mixed with tantalum. Then, another microcatheter was navigated into the other feeding branch and embolized similarly.
A check angiogram performed immediately after the embolisation showed cure of the VGAM and normalization of cerebral venous drainage.
The patient was discharged after three days
One month later, a follow up MRI showed occlusion of the vein of Galen aneurysmal malformation. As compared to the previous scan, ventriculomegaly had decreased. Sulcal prominence was more as compared to the previous scan. The tonsillar herniation had reverted.
DISCUSSION:
A vein of Galen malformation is seen more often in male children. This is one of the true congenital vascular malformations in the brain. This occurs due to fistulous communication occurring in the median vein of prosencephalon (a precursor of the vein of Galen). Due to the presence of this malformation at birth, the normal cerebral venous anatomy is altered into an anomalous pattern with persistence of embryonic patterns. Usually there is no difficulty during pregnancy and labour. Caesarean delivery is a maternal indication in most cases
Our patient was delivered normally and was normal till his parents noticed enlarging head circumference and veins on of the face.
The enlarging head circumference is attributed to the increasing fluid in the brain. Due to this enlargement, the fontanelles remain open.. The prominence of the veins on the face was due to the cavernous drainage of the cerebral venous drainage with retrograde flow in the superior ophthalmic vein which eventually drained via the facial veins.
The transarterial embolization procedure caused immediate relief from venous hypertension enabling the cerebral venous drainage from the brain at normal pressures. This also allowed resorption of the CSF and interstitial fluid and hence reduction in the size of the ventricles.
Transarterial embolisation has been the primary therapeutic procedure in the treatment of vein of Galen aneurysmal malformation
FAQs.
Q: Is this a congenital problem and is it hereditary?
A: Vein of Galen aneurysmal malformation is one of the truly congenital vascular malformations of the brain - the others being pial AVF and dural sinus malformations. It is not a hereditary conditione.
Q: How is this condition diagnosed?
A: It is now commonly diagnosed on antenatal USG screening. However, often it is picked up late due to cardiac problems in neonates and due to clinical presentation like increasing head size prominence of veins on the face in infants.
Q: Why does it occur?
A: The vein of Galen malformation occurs due to abnormal shunt/shunts which develop in the choroid plexus or the median vein of prosencephalon (which is the precursor of the vein of Galen in full term babies) during development of the fetal brain.
Q: Is it possible to diagnose and predict the prognosis of the child before birth?
A: The diagnosis of the malformation is often possible before birth by antennal sonography or MRI. MRI also helps in imaging the lesion and in defining the extent of brain damage due to the malformation. White matter changes are prognostic of bad outcome and often a contraindication to treatment.
Q: Does the child need to be delivered through Caesarean section?
A: INot necessarily. The indication of Caesarean section is purely an obstetric problem and not related to fetal disease. The increase in the size of the head is usually in the second half of infancy. Generally, the guideline is that, if the baby is capable of surviving, then it will have no problem of undergoing the strain of delivery. If the baby's clinical condition is poor and needs a Caesarean section, then it may be inferred that the child may not survive for long after delivery or may have multi-system failures.
Q: What is the immediate problem expected after delivery?
A: Following birth, there is a sudden change in blood flow pattern with the lung being the low resistance zone. This may lead to failure of the heart due to cardiac overload. This usually lasts for the first week. Following this the heart gets used to the high volume overloads and works efficiently. Often, there is associated patent foramen ovale/ patent ductus arteriosus due to VGAM high cardiac output phenomenon. During this period, support by nasal oxygen or a ventilator may help patient to be stabilized
Q: What is the natural course of this disease?
A: The child may have problems due to cardiac overload during the early neonatal period. Once this problem is overcome, the child remains stable for some time. He starts having problems with fluid drainage from the brain due to high venous pressure preventing resorption of interstitial fluid and CSF.. This is the function of veins during early infancy. However, the higher venous pressure hampers normal venous drainage. This leads to accumulation of fluid in the ventricles of the brain and also increased interstitial fluid causing delayed myelination of the brain and may cause permanent brain damage.
The unfused fontanelles protect the brain from the increasing pressure. The head circumference keeps increasing as a consequence.
Around six months of age two important changes occur. They are the maturation of the jugular bulb and capture of the cavernous sinus. When the jugular bulb matures, normally there is no adverse consequence. However when there is dysmaturation of the jugular bulb, the venous drainage of the brain is further compromised and leads to increasing pressure in the brain causing increasing fluid retention in the brain. If an alternate pathway for brain drainage is established by rerouting of blood through the cavernous sinus, the brain venous congestion drops. If not, brain damage ensues.
The "cavernous capture" for the venous drainage is manifested by prominence of the veins in the face. Slowly, the venous pressure in the brain increases leading to improper myelination and delayed / abnormal functional brain development. This leads to mental retardation over course of time
Q: What are the treatment options for this condition?
A: Embolisation is the most efficient treatment for this condition. The timing of the embolisation depends on the clinical condition of the baby.
Q: What is the most appropriate time for embolisation?
A: Unless there is an emergency (medically unmanageable congestive cardiac failure or severely raised intracranial pressure), the best time for embolisation of VGAM is from 6 to 9 months. This is the window period where in the baby has gained sufficient weight and is stable to undergo general anesthesia with less risk as compared to a new born baby. The abnormal changes in myelination are yet to start and venous drainage pathways are modeling according to maturation of the jugular bulbs and capture of the cavernous sinus for cerebral venous drainage. Most single hole (mural) VGAMs are cured in one session. The choroidal type of the VGAM may need more than one session of embolisation. Staging of embolisation is possible in the treatment of the choroidal type of VGAM.
Q: What are the risks associated with embolisation of VGAM?
A: This procedure is performed under GA. The risk of embolisation mainly depends on the injection of the concentrated glue for treating the high flow fistula. Glue polymerization is rapid; also the flow in the VGAM being rapid may cause excessive penetration of the glue on to the venous side. Hence the major risk of the procedure is the possibility of sticking the catheter in the process of embolisation, non target embolisation and occlusion of the venous outflow due to glue penetration. Once the embolisation is complete, there is sudden change in flow dynamics leading to the possibility of hemorrhagic complications not directly related to the glue injection. However this is managed by electively putting the patient on a respirator for 24-48 hrs following embolisation.
Q: Is embolisation permanent?
A: Glue used in the treatment AVM has permanent effect on the malformation.
Q: Will the patient have normal outcome after embolisation?
A: Once the VGAM is treated in the window period, usually the neurological development of the babies is normal.
Q: What is the cost of the procedure?
A: There is significant expense of the disposable consumables (microcatheters, guidewires, glue etc.) used for the embolisation. In our institution, the total cost is around Rs.75,000.
Case 24: Contributed
by Drs.Wuppalapati Siddhartha
Other Cases
The parents of a nine-month-old boy came for consultation for prominent veins on the face and progressive increase in the size of the boy's head. He used to sweat profusely during breast feeding.
On examination, he was fairly nourished, conscious and stable. Pulse was 100/min and respiration normal. There was no neurological deficit. Developmental milestones were within normal limits. He had prominent veins over the face; his head being a bit large for the age. 2D echo of the heart was normal. A CT scan of the brain showed a vein of Galen aneurysmal malformation.
 | ||
Fig.
1 |
An MRI confirmed this. The brain had no abnormalities in white matter development. The prominent artery supplying the malformation was the posterior choroidal artery. The ventricles were dilated and there was obvious cerebellar tonsillar herniation due to venous hypertension
|  | |
Fig
2 | Fig
3 | |
The left vertebral angiogram showed a high flow vein of Galen malformation supplied by two choroidal vessels from the right posterior cerebral artery. Neither of the posterior cerebral arteries was opacified due to high flow through the fistula
 | |
| Fig
4 |
A microcatheter over a microwire was navigated to the site of fistula. Selective injection opacified the feeding artery and mural fistula. Embolization was carried out with pure glue mixed with tantalum. Then, another microcatheter was navigated into the other feeding branch and embolized similarly.
 |  |
Fig
5 | Fig
6 |
A check angiogram performed immediately after the embolisation showed cure of the VGAM and normalization of cerebral venous drainage.
 |  |
Fig
7 | Fig
8 |
The patient was discharged after three days
One month later, a follow up MRI showed occlusion of the vein of Galen aneurysmal malformation. As compared to the previous scan, ventriculomegaly had decreased. Sulcal prominence was more as compared to the previous scan. The tonsillar herniation had reverted.
 |  |
Fig
9 | Fig
10 |
 |  |
Fig.
11 | Fig.
12 |
DISCUSSION:
A vein of Galen malformation is seen more often in male children. This is one of the true congenital vascular malformations in the brain. This occurs due to fistulous communication occurring in the median vein of prosencephalon (a precursor of the vein of Galen). Due to the presence of this malformation at birth, the normal cerebral venous anatomy is altered into an anomalous pattern with persistence of embryonic patterns. Usually there is no difficulty during pregnancy and labour. Caesarean delivery is a maternal indication in most cases
Our patient was delivered normally and was normal till his parents noticed enlarging head circumference and veins on of the face.
The enlarging head circumference is attributed to the increasing fluid in the brain. Due to this enlargement, the fontanelles remain open.. The prominence of the veins on the face was due to the cavernous drainage of the cerebral venous drainage with retrograde flow in the superior ophthalmic vein which eventually drained via the facial veins.
The transarterial embolization procedure caused immediate relief from venous hypertension enabling the cerebral venous drainage from the brain at normal pressures. This also allowed resorption of the CSF and interstitial fluid and hence reduction in the size of the ventricles.
Transarterial embolisation has been the primary therapeutic procedure in the treatment of vein of Galen aneurysmal malformation
FAQs.
Q: Is this a congenital problem and is it hereditary?
A: Vein of Galen aneurysmal malformation is one of the truly congenital vascular malformations of the brain - the others being pial AVF and dural sinus malformations. It is not a hereditary conditione.
Q: How is this condition diagnosed?
A: It is now commonly diagnosed on antenatal USG screening. However, often it is picked up late due to cardiac problems in neonates and due to clinical presentation like increasing head size prominence of veins on the face in infants.
Q: Why does it occur?
A: The vein of Galen malformation occurs due to abnormal shunt/shunts which develop in the choroid plexus or the median vein of prosencephalon (which is the precursor of the vein of Galen in full term babies) during development of the fetal brain.
Q: Is it possible to diagnose and predict the prognosis of the child before birth?
A: The diagnosis of the malformation is often possible before birth by antennal sonography or MRI. MRI also helps in imaging the lesion and in defining the extent of brain damage due to the malformation. White matter changes are prognostic of bad outcome and often a contraindication to treatment.
Q: Does the child need to be delivered through Caesarean section?
A: INot necessarily. The indication of Caesarean section is purely an obstetric problem and not related to fetal disease. The increase in the size of the head is usually in the second half of infancy. Generally, the guideline is that, if the baby is capable of surviving, then it will have no problem of undergoing the strain of delivery. If the baby's clinical condition is poor and needs a Caesarean section, then it may be inferred that the child may not survive for long after delivery or may have multi-system failures.
Q: What is the immediate problem expected after delivery?
A: Following birth, there is a sudden change in blood flow pattern with the lung being the low resistance zone. This may lead to failure of the heart due to cardiac overload. This usually lasts for the first week. Following this the heart gets used to the high volume overloads and works efficiently. Often, there is associated patent foramen ovale/ patent ductus arteriosus due to VGAM high cardiac output phenomenon. During this period, support by nasal oxygen or a ventilator may help patient to be stabilized
Q: What is the natural course of this disease?
A: The child may have problems due to cardiac overload during the early neonatal period. Once this problem is overcome, the child remains stable for some time. He starts having problems with fluid drainage from the brain due to high venous pressure preventing resorption of interstitial fluid and CSF.. This is the function of veins during early infancy. However, the higher venous pressure hampers normal venous drainage. This leads to accumulation of fluid in the ventricles of the brain and also increased interstitial fluid causing delayed myelination of the brain and may cause permanent brain damage.
The unfused fontanelles protect the brain from the increasing pressure. The head circumference keeps increasing as a consequence.
Around six months of age two important changes occur. They are the maturation of the jugular bulb and capture of the cavernous sinus. When the jugular bulb matures, normally there is no adverse consequence. However when there is dysmaturation of the jugular bulb, the venous drainage of the brain is further compromised and leads to increasing pressure in the brain causing increasing fluid retention in the brain. If an alternate pathway for brain drainage is established by rerouting of blood through the cavernous sinus, the brain venous congestion drops. If not, brain damage ensues.
The "cavernous capture" for the venous drainage is manifested by prominence of the veins in the face. Slowly, the venous pressure in the brain increases leading to improper myelination and delayed / abnormal functional brain development. This leads to mental retardation over course of time
Q: What are the treatment options for this condition?
A: Embolisation is the most efficient treatment for this condition. The timing of the embolisation depends on the clinical condition of the baby.
Q: What is the most appropriate time for embolisation?
A: Unless there is an emergency (medically unmanageable congestive cardiac failure or severely raised intracranial pressure), the best time for embolisation of VGAM is from 6 to 9 months. This is the window period where in the baby has gained sufficient weight and is stable to undergo general anesthesia with less risk as compared to a new born baby. The abnormal changes in myelination are yet to start and venous drainage pathways are modeling according to maturation of the jugular bulbs and capture of the cavernous sinus for cerebral venous drainage. Most single hole (mural) VGAMs are cured in one session. The choroidal type of the VGAM may need more than one session of embolisation. Staging of embolisation is possible in the treatment of the choroidal type of VGAM.
Q: What are the risks associated with embolisation of VGAM?
A: This procedure is performed under GA. The risk of embolisation mainly depends on the injection of the concentrated glue for treating the high flow fistula. Glue polymerization is rapid; also the flow in the VGAM being rapid may cause excessive penetration of the glue on to the venous side. Hence the major risk of the procedure is the possibility of sticking the catheter in the process of embolisation, non target embolisation and occlusion of the venous outflow due to glue penetration. Once the embolisation is complete, there is sudden change in flow dynamics leading to the possibility of hemorrhagic complications not directly related to the glue injection. However this is managed by electively putting the patient on a respirator for 24-48 hrs following embolisation.
Q: Is embolisation permanent?
A: Glue used in the treatment AVM has permanent effect on the malformation.
Q: Will the patient have normal outcome after embolisation?
A: Once the VGAM is treated in the window period, usually the neurological development of the babies is normal.
Q: What is the cost of the procedure?
A: There is significant expense of the disposable consumables (microcatheters, guidewires, glue etc.) used for the embolisation. In our institution, the total cost is around Rs.75,000.