The term angioma covers various vascular malformations. Cerebral arteriovenous malformation (AVM) is a vascular anomaly that occurs in the brain. Under certain circumstances, this vascular tangle can rupture and cause a life-threatening cerebral hemorrhage. Here you will find further information as well as selected specialists and centers for the treatment of cerebral arteriovenous malformations.
Cerebral arteriovenous malformation is a special form of blood vessel anomaly that is classified as an angioma.
An angioma is a blood vessel malformation that is either
is congenital. A special vascular anomaly is arteriovenous malformation (AVM), which is not actually an angioma. AVM is not a tumor!
If the AVM is located in the brain, it is referred to as a cerebral arteriovenous malformation (CAVM ) or intracranial arteriovenous malformation.
Hemangioma in a newborn © komokvm | AdobeStock
In a zAVM, the cerebral arteries are directly connected to the cerebral veins, i.e. without capillaries (small vessels). This vascular tangle is surrounded by healthy brain. An angioma or cerebral arteriovenous malformation can occur in all regions of the brain.
The vascular architecture, i.e. the structure of a zAVM, is often complicated. Due to the lack of capillaries, the blood flows much faster. The blood vessels in the angioma are therefore exposed to high stress.
The vessel walls in the zAVM are generally thinner and for these two reasons the blood vessels can rupture. As a result, a cerebral hemorrhage can occur, causing severe damage to the brain or leading directly to death.
Cerebral arteriovenous malformation is very rare. About 0.05% of the population have an angioma in the brain.
About 10% of patients with zAVM also have an aneurysm in the brain. The aneurysms usually form on the arteries that supply the angioma.
An AVM with a size of less than 3 cm is referred to as a small angioma. A medium angioma has a diameter of 3-6 cm, and a large angioma is over 6 cm in size.
Angiomas are basically divided into
A hemangioma is an embryonic tumor in which the cells on the inside of the vessel (endothelium) multiply. This results in the formation of a new vascular cavity.
A lymphangioma is a benign tumor disease of the lymphatic vessels in which the cells of the lymphatic vessels multiply.
An angiectasia is a dilation of a blood vessel and a varix(varicose vein) is a nodular dilated superficial vein.
In arteriovenous malformation (AVM), there is direct blood flow from an artery into a vein as described above.
Not every AVM in the brain causes symptoms. However, cerebral angiomas often cause
Depending on the location of the cerebral AVM, there are also
are possible. As there is no natural resistance from the microscopically small capillaries, the blood pressure in the surrounding brain tissue is reduced. This can lead to neurological deficits.
As mentioned, there is also an increased risk of a spontaneous cerebral hemorrhage. This can result in a life-threatening stroke.
The risk of a cerebral hemorrhage in people with zAVM is 1-4% per year. The risk is higher if a cerebral hemorrhage has already occurred as a result of a zAVM.
However, there are also studies that estimate a higher risk of bleeding from a zAVM. For example, an American study reports that it can be between 0.9% and 34.4% per year, depending on
A cerebral hemorrhage has the following symptoms
A cerebral hemorrhage is life-threatening!
A cerebral angioma can lead to seizures. The causes of these seizures are
are possible causes.
Due to the missing capillary bed between the artery and vein, the blood flow is significantly increased. As a result, the surrounding healthy brain tissue lacks the blood needed for normal brain function. This leads to a chronic lack of blood flow and oxygen supply to the brain.
This circulatory disorder in the brain can lead to neurological deficits, such as
Neurological dysfunctions, especially of a more general nature such as
can also be caused by pressure overload in the veins.
A cerebral arteriovenous malformation occurs in the blood vessels in the brain © peterschreiber.media | AdobeStock
As cerebral angiomas are usually congenital , around 50% of cerebral AVMs are discovered within the first 30 years of life. Cerebral AVMs in which no hemorrhage has yet occurred are often detected as an incidental finding during an imaging examination.
However, an angioma in the brain is also suspected if the complaints and symptoms indicate a disorder in the brain. These include
If a hemorrhage has already occurred, a cranial computer tomography (CCT) is usually performed in the acute stage due to the symptoms. CCT often reveals small, atypical cerebral hemorrhages, occasionally also blood in the subarachnoid space.
Such atypical hemorrhages are then examined in more detail using magnetic resonance imaging(MRI) in order to either detect or rule out an angioma.
For the treatment of cerebral AVM, it is important to know the exact vascular situation in the angioma and in the brain. This can be studied using digital subtraction angiography.
Computed tomography (CT) of the head (cranial computed tomography, CCT) is an X-ray examination. The body is exposed to a low level of radiation.
As the examination only takes a few minutes, a CT scan can be used to quickly assess the severity of a cerebral hemorrhage. The blood vessels of the zAVM and thus the angioma itself can be visualized by administering a contrast agent(CT angiography).
Magnetic resonance imaging (MRI) takes up to an hour. However, the advantage of MRI is that the body is not exposed to radiation. The quality of the image data obtained is also somewhat better.
As a result, it is mainly accompanying symptoms that are attributable to the angioma that can be depicted more accurately. Due to the lack of radiation exposure, MRI is also preferred for follow-up examinations after treatment.
Magnetic resonance angiography(MRA), i.e. the targeted administration of a contrast agent, allows the blood vessels to be better visualized.
Digital subtraction angiography (DSA) is the most reliable way of detecting a zAVM and visualizing the blood flow. This medical procedure is a special form of angiography.
It is usually carried out in special clinics prior to treatment or as a follow-up examination after treatment. It is a catheter examination.
The doctor first punctures the inguinal artery. Through the opening created in this way, he guides the catheter via the aorta past the heart and into the arteries supplying the brain. The target arteries are those that supply the angioma.
Under X-ray control, he injects a contrast agent into the vessels, making them clearly visible. The computer then automatically removes bones, brain tissue and other structures from the images.
This method can be used, for example, to clarify
A cerebral AVM does not always need to be treated immediately. In some cases, it is better to observe the angioma first. To do this, doctors must assess the risk and consequences of a possible cerebral hemorrhage. The risk of the cerebral angioma ever bleeding in the course of a lifetime is around 50%.
After a thorough medical consultation about
many patients today decide to undergo treatment. The risks also depend on the patient's age and general condition.
Doctors also usually recommend treatment due to the relatively high risk of bleeding.
However, some recent studies suggest waiting and observing in the case of asymptomatic zAVM. Asymptomatic means that these angiomas do not cause any symptoms.
The aim of any treatment is to stop the direct blood flow from the arteries to the veins in the angioma. To do this, either the angioma is completely removed or the vessels in the angioma or the supplying and draining vessels are blocked.
There are basically three treatment options available for angiomas.
In endovascular angioma treatment (embolization), the feeding and draining vessels are sealed, for example with a special adhesive and, if necessary, with small coils. The doctors insert these into the angioma via a catheter.
During surgical angioma treatment, the angioma is completely removed and the feeding and draining vessels are closed.
In stereotactic radiosurgical angioma treatment (stereotactic irradiation), the angioma is irradiated. This completely closes the vessels in the angioma.
As the treatment is specially adapted to the conditions in the angioma, not every procedure is suitable for every angioma. Doctors weigh up the advantages and disadvantages of the individual angioma treatment procedures and their chances of success.
In certain zAVMs, a combination of different procedures is also required to close the angioma. It is important to discuss the angioma treatment options with the patient in detail.
During embolization (endovascular angioma treatment), a catheter is inserted into an artery from the groin to the brain.
A special adhesive (embolizate) and, if necessary, small platinum spheres are inserted under X-ray control. This closes the vessels from the inside.
Embolization is performed either under general or local anaesthetic. Several sessions may be necessary. Embolization alone cannot usually completely close a zAVM.
During embolization, there is a risk that the embolate could end up in the wrong blood vessel. It could block this, which would lead to damage to other areas of the brain.
Depending on the size and location of the zAVM, surgical angioma removal may be an option. Surgery is the best way to remove an angioma. However, not every patient is suitable for this.
If necessary, one or more embolizations are performed preoperatively to reduce the blood flow to the angioma. This is intended to reduce the size of the angioma (down-grading), which improves the chances of success of open skull surgery.
The risks of surgical angioma treatment result from
Among other things, it can lead to
If smaller angiomas (2 to 3 cm in diameter) are located
are unfavorable for surgery, they can be irradiated using a gamma knife or linear accelerator. After stereotactic irradiation of the zAVM, the cells of the blood vessels in the cerebral angioma change. They gradually enlarge and very slowly (sometimes over years) close the blood vessels.
As long as the vessels in the angioma are not yet closed, there is still a risk of bleeding in the cerebral angioma. If the angioma cannot be completely eliminated with radiotherapy, a second course of radiotherapy may be necessary after a few years.
Around 70% of zAVMs are completely closed after 2 years, after 3 years it is around 80%. Depending on
side effects occur in about 2 to 3% of cases.
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