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Radiology
Left transverse sinus dural AVM: Endovascular
treatment
A sixty-year-old man had sudden onset headache which was followed by severe nausea and vomiting. He developed difficulty in speech, unable to comprehend simple verbal commands. Over a period of 5 days, he partially recovered speech comprehension. A CT scan had revealed a blood clot in the left parietal region with surrounding edema
He did not have any loss of consciousness. He was diagnosed to have Wernicke's aphasia due to the clot. He reached our hospital 15 days after the first symptom. All his basic lab investigations were within normal limits.
At our hospital, he underwent an angiogram. The DSA examination revealed a dural fistula on the left transverse sinus.
The drainage of the fistula was into a cortical vein which traversed across the parietal lobe and drained into the superior sagital sinus. The supply to the fistula was from the hypertrophied left middle meningeal artery and from the dural branches of the left occipital artery to the left transverse sinus. The left vertebral angiogram showed reformation of the left occipital artery from C1 - C2 collaterals distal to the dural branches to the dural AVM.
The middle meningeal artery was superselectively cannulated and embolized with glue to excluded significant part of the dural AVM from circulation. A check angiogram performed after one month showed complete cure of the dural AVM.
Following the embolisation, there was rapid improvement in the patient's speech.
DISCUSSION:
Adult dural AVM is not very common disease. The exact etiology is not established. There is a significant correlation of dural sinus thrombosis associated with dural AVM. It is also postulated from this fact, that dural AVM maybe secondary to dural sinus thrombosis.
Clinical symptoms are due to the hyperdynamic circulation or due to venous hypertension.
The hyperdynamic circulation in the external carotid artery can give rise to the symptoms of bruit, pulsatile tinnitus and neuralgias. The venous hypertension is caused due to the competition of the drainage of the dural AVM with that of the cerebral venous drainage. This leads to symptoms of convulsions, altered sensorium, progressive neurological deficits and may also lead to brain hemorrhage especially when there is severe venous hypertension.
In this patient, the dural AVM was draining into the cortical vein which finally drained into the superior sagital sinus. The draining vein had competition with the normal cerebral venous drainage of the parietal lobe and led to venous hemorrhage into the parietal lobe. This bleed with surrounding edema caused the neurological deficit.
Angiogram showed the dural AVM supply from the middle meningeal artery and also from the dural branches of the occipital artery. Transarterial approach in this case was most appropriate for treating the dural AVM. The middle meningeal artery was selectively cannulated and embolized using glue. The glue occluded the artery feeding the dural AVM and also reduced the flow in the dural AVM. The supply from the occipital artery was also reduced due to iatrogenic spasm in the artery due to catheterization of the artery. This led to cure of the dural AVM. The cure of dural AVM led to immediate normalization of the venous pressure and eliminated the competition to the cerebral venous drainage leading to speedy recovery from the venous infarct and edema.
The patient's speech improved completely. There were no neurological sequelae. He was asked to continue anticonvulsant drugs for a short period following which he was advised to taper the drug in consultation with the referring physician.
FAQs.
Q: What is a dural arteriovenous shunt? What is the cause of the dural AVM/AVF? Is it hereditary?
A: Dural arteriovenous shunts are abnormal shunts in the covering of the brain called dura. Usually they are located near the big veins in the dura, which drain the brain.
Adult dural AVMs are often spontaneously acquired with no obvious etiology. Some of the patients have been documented to have dural sinus thrombosis and later to have the dural AVM in the thrombosed dural sinus. However, not all dural sinus thrombosis progress to dural AVM. There has been no evidence to prove that this disease is congenital or hereditary and transmitted in family.
Q: What are the early symptoms or signs of dural AVM?
A: This usually depends on the location of the shunt. One of the commonest symptom is headache. The other symptoms which are commonly observed are: tinnitus, bruit, proptosis, papilledema, giddiness, disorientation, neuralgias, focal neurological deficits and global neurological deficits like dementia.
Q: How is this condition diagnosed? What will happen if it is not treated?
A: Diagnosis is usually done on the imaging. Strong suspicion can be raised on CT scan or MRI of the brain. Confirmation and therapeutic planning is done by angiography. The natural history of the disease is progressive deterioration due to rise in the venous hypertension which may lead to neurological deficits, intracranial hemorrhages and even death. There are few cases which have spontaneous thrombosis and cure.
Q: What are the therapeutic options?
A: Today the first option for the treatment of dural AVM is the embolisation. This is an endovascular procedure. This can be done either by transarterial route or through the transvenous route to exclude the dural AVM from circulation. Radiosurgery also has been performed on few occasions in selected case with encouraging preliminary results. Surgery is done when embolisation is not an option or it is to aid the embolisation for access to an isolated dural sinus
Q: Is embolisation permanent?
A: Coils and glue which are presently used in the treatment of the dural AVM have permanent effect on the vessel they are placed in.
Q: Will the patient improve completely after the embolisation?
A: Most of the patients have near total recovery after the dural AVM is cured. The neurogical deficit which is due to impaired circulation will be reversed. However complete recovery after long standing symptoms or due to brain hemorrhage may not be possible.
Q: What is the risk associated in embolisation of dural AVM?
A: Most often, the procedure is performed under general anaesthesia hence risk of anaesthesia is included in the procedure. The risk associated with the embolisation of the dural AVM depends on the angioarchitecture of the AVM. When the angioarchitecture is simple and there is straight forward, embolisation risk is minimal. The risk involved here is the risk of non target embolisation leading to embolic occlusion of normal vessels with resultant ischemic problems. Complex embolisations involving the transvenous sinus occlusion carries higher risk of complications due to underestimated effect of dural sinus sacrifice and non target occlusion leading to compromise of normal venous drainage leading to venous ischemic problems.
Q: What is the cost of the procedure?
A: At this institution, there no doctors' fees or stay charges, The cost of the consumables(catheters, glue, coils etc) may range between Rs. 20,000 and Rs. 100,000 or more. Transareterial embolisation often requires lesser consumables than the transvenous embolisation procedure
Case 22: Contributed
by Dr.Wuppalapati Siddhartha.
Other Cases
A sixty-year-old man had sudden onset headache which was followed by severe nausea and vomiting. He developed difficulty in speech, unable to comprehend simple verbal commands. Over a period of 5 days, he partially recovered speech comprehension. A CT scan had revealed a blood clot in the left parietal region with surrounding edema
 | ||
Fig.
1 |
He did not have any loss of consciousness. He was diagnosed to have Wernicke's aphasia due to the clot. He reached our hospital 15 days after the first symptom. All his basic lab investigations were within normal limits.
At our hospital, he underwent an angiogram. The DSA examination revealed a dural fistula on the left transverse sinus.
|  |
Fig
2 | Fig
3 |
The drainage of the fistula was into a cortical vein which traversed across the parietal lobe and drained into the superior sagital sinus. The supply to the fistula was from the hypertrophied left middle meningeal artery and from the dural branches of the left occipital artery to the left transverse sinus. The left vertebral angiogram showed reformation of the left occipital artery from C1 - C2 collaterals distal to the dural branches to the dural AVM.
 |  |
| Fig
4 | Fig
5 |
The middle meningeal artery was superselectively cannulated and embolized with glue to excluded significant part of the dural AVM from circulation. A check angiogram performed after one month showed complete cure of the dural AVM.
 |  |
| Fig
6 | Fig
7 |
Following the embolisation, there was rapid improvement in the patient's speech.
DISCUSSION:
Adult dural AVM is not very common disease. The exact etiology is not established. There is a significant correlation of dural sinus thrombosis associated with dural AVM. It is also postulated from this fact, that dural AVM maybe secondary to dural sinus thrombosis.
Clinical symptoms are due to the hyperdynamic circulation or due to venous hypertension.
The hyperdynamic circulation in the external carotid artery can give rise to the symptoms of bruit, pulsatile tinnitus and neuralgias. The venous hypertension is caused due to the competition of the drainage of the dural AVM with that of the cerebral venous drainage. This leads to symptoms of convulsions, altered sensorium, progressive neurological deficits and may also lead to brain hemorrhage especially when there is severe venous hypertension.
In this patient, the dural AVM was draining into the cortical vein which finally drained into the superior sagital sinus. The draining vein had competition with the normal cerebral venous drainage of the parietal lobe and led to venous hemorrhage into the parietal lobe. This bleed with surrounding edema caused the neurological deficit.
Angiogram showed the dural AVM supply from the middle meningeal artery and also from the dural branches of the occipital artery. Transarterial approach in this case was most appropriate for treating the dural AVM. The middle meningeal artery was selectively cannulated and embolized using glue. The glue occluded the artery feeding the dural AVM and also reduced the flow in the dural AVM. The supply from the occipital artery was also reduced due to iatrogenic spasm in the artery due to catheterization of the artery. This led to cure of the dural AVM. The cure of dural AVM led to immediate normalization of the venous pressure and eliminated the competition to the cerebral venous drainage leading to speedy recovery from the venous infarct and edema.
The patient's speech improved completely. There were no neurological sequelae. He was asked to continue anticonvulsant drugs for a short period following which he was advised to taper the drug in consultation with the referring physician.
FAQs.
Q: What is a dural arteriovenous shunt? What is the cause of the dural AVM/AVF? Is it hereditary?
A: Dural arteriovenous shunts are abnormal shunts in the covering of the brain called dura. Usually they are located near the big veins in the dura, which drain the brain.
Adult dural AVMs are often spontaneously acquired with no obvious etiology. Some of the patients have been documented to have dural sinus thrombosis and later to have the dural AVM in the thrombosed dural sinus. However, not all dural sinus thrombosis progress to dural AVM. There has been no evidence to prove that this disease is congenital or hereditary and transmitted in family.
Q: What are the early symptoms or signs of dural AVM?
A: This usually depends on the location of the shunt. One of the commonest symptom is headache. The other symptoms which are commonly observed are: tinnitus, bruit, proptosis, papilledema, giddiness, disorientation, neuralgias, focal neurological deficits and global neurological deficits like dementia.
Q: How is this condition diagnosed? What will happen if it is not treated?
A: Diagnosis is usually done on the imaging. Strong suspicion can be raised on CT scan or MRI of the brain. Confirmation and therapeutic planning is done by angiography. The natural history of the disease is progressive deterioration due to rise in the venous hypertension which may lead to neurological deficits, intracranial hemorrhages and even death. There are few cases which have spontaneous thrombosis and cure.
Q: What are the therapeutic options?
A: Today the first option for the treatment of dural AVM is the embolisation. This is an endovascular procedure. This can be done either by transarterial route or through the transvenous route to exclude the dural AVM from circulation. Radiosurgery also has been performed on few occasions in selected case with encouraging preliminary results. Surgery is done when embolisation is not an option or it is to aid the embolisation for access to an isolated dural sinus
Q: Is embolisation permanent?
A: Coils and glue which are presently used in the treatment of the dural AVM have permanent effect on the vessel they are placed in.
Q: Will the patient improve completely after the embolisation?
A: Most of the patients have near total recovery after the dural AVM is cured. The neurogical deficit which is due to impaired circulation will be reversed. However complete recovery after long standing symptoms or due to brain hemorrhage may not be possible.
Q: What is the risk associated in embolisation of dural AVM?
A: Most often, the procedure is performed under general anaesthesia hence risk of anaesthesia is included in the procedure. The risk associated with the embolisation of the dural AVM depends on the angioarchitecture of the AVM. When the angioarchitecture is simple and there is straight forward, embolisation risk is minimal. The risk involved here is the risk of non target embolisation leading to embolic occlusion of normal vessels with resultant ischemic problems. Complex embolisations involving the transvenous sinus occlusion carries higher risk of complications due to underestimated effect of dural sinus sacrifice and non target occlusion leading to compromise of normal venous drainage leading to venous ischemic problems.
Q: What is the cost of the procedure?
A: At this institution, there no doctors' fees or stay charges, The cost of the consumables(catheters, glue, coils etc) may range between Rs. 20,000 and Rs. 100,000 or more. Transareterial embolisation often requires lesser consumables than the transvenous embolisation procedure