Cerebral arteriovenous malformations are the most common type of cerebrovascular malformation and are located superficially or deeply in the brain. The malformed vessels are composed of arteries and veins, some of which contain aneurysms and venous aneurysms, and the arteriovenous malformations are of various sizes and shapes. They occur in the frontal and parietal lobes, but also in the temporal lobe, occipital lobe, ventricles, thalamus, cerebellum and brainstem. According to the size of the lesion: <2.5 cm in diameter is small, 2.5-5 cm is medium, 5-7.5 cm is large, and >7.5 cm is extra large. These arteriovenous malformations can also occur in the dura mater.
They often manifest as epilepsy with spontaneous cerebral hemorrhage, there may be incomplete paralysis of limbs, some cases have increased intracranial pressure similar to brain tumors, larger cerebral arteriovenous malformations sometimes cause symptoms of intracranial stasis, and vascular murmurs are sometimes heard on cranial orbital auscultation. The disease is the most common type of cerebrovascular malformation and is located in the superficial or deep parts of the brain. The malformed blood vessels are composed of arteries and veins, some of which contain aneurysms and venous aneurysms, and the arteriovenous malformations of the brain include blood supplying arteries and draining veins of various sizes and shapes. They occur in the frontal and parietal lobes, but also in the temporal lobe, occipital lobe, ventricles, thalamus, cerebellum and brainstem. According to the size of the lesion: <2.5 cm in diameter is small, 2.5-5 cm is medium, 5-7.5 cm is large, and >7.5 cm is extra large. Such arteriovenous malformations can also occur in the dura mater.
Treatment options.
1.Surgical method: microscopic craniotomy is a surgical method to remove the arteriovenous vessels directly, i.e. craniotomy. The artery supplying the malformed vessel is cut off and the malformed vessel mass is stripped, and finally the draining vein is cut off.
2.Surgical indications: Patients with one of the following conditions, and the angiographic examination determines that the malformed vessels can be removed.
(1) History of spontaneous subarachnoid hemorrhage.
(2) Frequent epilepsy with poor results of drug treatment.
(3) Those with symptoms of progressive localized neurological damage or mental retardation (blood-stealing syndrome).
(4) Combined with intracranial hematoma or intracranial hypertension.
3. Contraindications to surgery.
(1) Arteriovenous malformations in the deep brain, internal capsule, basal ganglia, brainstem, etc.
(2) Extensive or multiple arteriovenous malformations.
(3) Incidental findings, asymptomatic.
(4) Older than 60 years old with serious diseases of heart, kidney and respiratory system.
4.The main purpose of cerebral arteriovenous malformation is to prevent bleeding, remove hematoma, improve blood theft and control epilepsy, and the treatment methods include
(1) malformation vascular resection.
(2) endovascular embolization treatment.
(3) γ-knife/X-knife radiation therapy.
5. The clinical manifestations are mainly cerebral local ischemia and recurrent hemorrhage. The details are as follows.
(1) hemorrhage: there is often no clear cause for the onset of hemorrhage, and patients often bleed from the rupture of malformed vessels, forming intracerebral hematoma or subarachnoid hemorrhage as the first symptom, accounting for 52%-70%, often with sudden onset, related to the patient’s physical activity and emotional fluctuations.
(2) Ischemia: It is seen in giant lesions, mostly due to long-term blood theft and causes whole brain atrophy leading to mental retardation, sometimes manifested as progressive mild hemiparesis and other brain dysfunction.
(3) Epilepsy: It is the main clinical manifestation of superficial AVM after hemorrhage, and its incidence is 28%-64%, which is related to the site and size of AVM.
(4) Headache: about 60% of patients usually have vascular headache, which may be caused by vasodilatation.
Cerebral arteriovenous malformation is the most common type of vascular malformation among cerebrovascular malformations, and it is a treatable and good disease. Stereotactic radiosurgery is one of the methods of treating arteriovenous malformations. The risk of bleeding remains after treatment, but chronic bleeding and formation of tension hematoma is less common in such patients, and chronic tension hematoma should be treated surgically.
At present, the main treatment measures for arteriovenous malformation and prevention of cerebral hemorrhage are as follows.
1.Surgical treatment: microscopic neurosurgical techniques are mostly used to remove the lesioned vascular mass, simple ligation of the blood supply artery is prone to recurrence and is not advocated now. In case of combined intracranial hematoma, emergency surgery is required, and the lesion is removed at the same time when possible.
2.Intravascular embolization therapy: for lesions deep in, located in important functional areas or high blood flow lesions, embolization therapy is appropriate. Commonly used embolization agents are NBCA and silk, wire or particles, but simple embolization treatment can only cure a small part of the lesion, and microsurgical resection can be performed after partial embolization.
3, stereotactic radiosurgery treatment: namely, X knife or γ knife, non-invasive, but expensive, slow effect, suitable for deep lesions less than 3cm in diameter or residual lesions after surgery and embolization.
4, non-surgical treatment: applicable to huge type located in important functional areas, with subarachnoid hemorrhage without hematoma, measures are: ① avoid triggering factors, such as violent mood swings, prohibition of smoking and alcohol, etc. ②Prevent and control seizures. ③Prevent rebleeding. ④Symptomatic treatment.