Frequently Asked Questions
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- Why is the location of an AVM in the brain important for treatment?
A critical issue in the treatment of arteriovenous malformations (AVMs) in the brain that have not ruptured is the location of the AVM. Superficial AVMs, located in the brain surface, are easier to reach during surgery than deeper AVMs, located closer to the center of the head or brainstem. Surgery is often not recommended if the AVM is close to, adjacent to, or incorporating critical control centers on the surface of the brain that relate to language function, reading, writing, speaking comprehension, movement, critical sensation, vision and other sensory functions.
- What determines whether or not an AVM in the brain should be treated?
A number of factors influence whether or not an arteriovenous malformation (AVM) in the brain should be treated. First and foremost is if the AVM has ruptured, if it caused a brain hemorrhage, then doctors generally recommend treatment. They then decide which treatment is going to have the least risk of causing any neurological problem and the highest chance of obliterating the AVM. Often, the preferred choice is a combination of surgery with endovascular embolization, and, in some cases, surgery and stereotactic radiosurgery. For large AVMs, focused radiation therapy often given in a few doses may not cure the AVM, but may shrink it sufficiently to make it acceptable for treatment with surgery. That may take two or three years. Multiple, staged embolization procedures can have similar effects to shrink the AVM in a shorter time period. The other critical issue in AVMs that have not ruptured is the location of the AVM. The judgment has to be made individually in each case based on the predicted risk of hemorrhage, which depends on the AVM's location, the characteristics of the involved blood vessels, and whether or not it has bled. It also depends on the predicted risk of having a neurological deficit from the treatment, and that may depend on the surgical grade that applies to that AVM.
- How common are arteriovenous malformations (AVMs) in the brain?
Fortunately, arteriovenous malformations (AVMs) in the brain are not common. Doctors see hemorrhage from AVMs in somewhere between two and four people per 100,000 – 2,240 per million is a reasonable estimate.
- When is stereotactic radiosurgery not suitable for AVMs in the brain?
There are a couple of drawbacks to the use of stereotactic radiosurgery for arteriovenous malformations (AVMs) in the brain. One is that it's much less effective for larger AVMs (larger than about an inch in diameter), because the chance of the AVM completely disappearing with radiation decreases substantially. Second, the process of obliteration of the AVM after radiosurgery is something that takes time. It can take one to three years in some cases. So, while the AVM is shrinking and disappearing, there is still a risk of bleeding from the blood vessels in the AVM that remain open. So, there's a lag phase (delay) before one experiences complete protection from future hemorrhage.
- What are the treatment options for a brain AVM in children?
Treatment options for arteriovenous malformations (AVMs) in the brain in children where an AVM has caused a hemorrhage are the same as for adults. What's unique about children is, first, there is a very long period of time (their natural life span) ahead of them, a long period of time during which they are at risk of having a brain hemorrhage. Doctors are therefore more direct about trying to treat AVMs in children, to protect them for their future and making sure of the quality of their future potential life. Secondly, children often have relatively diffuse AVM blood vessels that have not coalesced into a compact nidus (core), and that influences how the surgery is done and influences how radiation therapy is done. Finally, children are very resilient. They get through surgery with fewer complications and problems than adults do, and if there are any neurological problems related to hemorrhage from the AVM or the treatment itself, children have a greater capacity for brain recovery and recovery of function than adults do. This is called plasticity or recoverability of the brain.
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- What happens during focused radiation therapy for an AVM in the brain?
Doctors can use focused radiation therapy to treat arteriovenous malformations (AVMs) in the brain. This involves a robotic image-guided device that accurately beams the radiation therapy to the AVM. In contrast to the Lex-L original technique, they don't have to use a spherical spot size, but the beam can be shaped for an irregular AVM. The robotic arm rotates around the head, and beams coming in from various different directions hit the AVM. The amount of radiation on a small AVM is aggregated or focused on one particular area, largely to the exclusion of radiation exposure to the rest of the brain. Focused radiation therapy to treat arteriovenous malformations (AVMs) in the brain is an outpatient technique administered non-invasively. There are no pins in the head and no head frame. It's done purely by positioning the head precisely and using image guidance, so it's a painless outpatient procedure. In some cases, it can be done in a single treatment, and the person goes home immediately after. In other cases, it takes a series of treatments, especially if the AVM is a larger.
- How can the removal of an AVM in the brain cause aphasia?
If an arteriovenous malformation (AVM) is located in either the speech center or receptive language areas of the brain, then disrupting that area while removing the AVM may cause aphasia (loss of speech) or disruption in reading, writing or language functions. Great care is taken to avoid injury and neurological deficit if an AVM is treated near these eloquent brain areas.
- How successful is surgery for an AVM in the brain?
Because surgery results in the complete elimination of an arteriovenous malformation (AVM) in the vast majority of cases, more than 98% to 99% of AVMs are completely obliterated. The therapeutic method, or technique that most effectively eliminates the risk of hemorrhages, is surgical removal, but it's got to be done without causing neurological disability. That's the key issue, and in some cases, surgery is not possible. For instance, if the grade of the AVM is too high and therefore the surgical risk is too high, alternative methods will have to be used if treatment is recommended. In these cases, stereotactic radiosurgery (a form of focused radiation therapy) or endovascular embolization are viable alternatives.
- How do doctors grade arteriovenous malformations (AVMs) in the brain?
The technique doctors use to assess the key factors that increase the complexity or surgical difficulty of an arteriovenous malformation (AVM) in the brain is a grading scale that helps to predict what the surgical risk is. The grading scale involves looking at the size of an AVM and its location adjacent to or distant from critical control centers in the brain and the depth in the brain marked by the venous draining pattern. A grade 1 AVM is small and on the surface, usually easy to treat surgically. A grade 5 AVM is large and adjacent to critical areas, deep in the brain, and much more difficult to treat surgically.
- What happens during embolization for an AVM in the brain?
Embolization is used to block blood vessels that feed the AVM. This technique is used for AVM cure in some cases, but mostly to reduce the size of the AVM before surgery or radiosurgery. In embolization, a micro-catheter smaller than a piece of spaghetti is passed up and into the arteries of the head. It floats up through the bloodstream and into the blood vessels of the AVM. Then a glue-like substance and/or tiny platinum micro-coils are placed into the abnormal blood vessels to progressively block them off. Once they're blocked off, they're easier to separate from the brain tissue, and surgery can be done safely with less blood loss. Embolization also improves the results of surgery while reducing the chance of problems with bleeding during or after the surgery.
- Why is embolization needed for an AVM in the brain?
In some cases, arteriovenous malformations (AVMs) in the brain, particularly very large AVMs, have to be reduced in size in order to make surgery safer. They have to be reduced in size in order to minimize the chance of bleeding during the surgery, which is one of the key risks. Today that's done with by embolization (obstruction of a blood vessel) through a small and flexible micro-catheter introduced into the arteries of the brain. The catheter is used to place a glue-like substance and/or tiny platinum micro-coils into the abnormal blood vessels of the AVM to progressively block them off. Once they're blocked off, they're easier to separate from the brain tissue, and surgery can be done safely with less blood loss.
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- Why do I need an MRI scan if I have an AVM in the brain?
A magnetic resonance imaging (MRI) scan is a typical diagnostic test done for an arteriovenous malformation (AVM) in the brain. This allows doctors to plan very precisely where they need to enter the brain, how they need to deal with the blood vessels and how the AVM can be removed completely.
- How do doctors diagnose the cause of a seizure?
After a person has had a single seizure, there is the possibility of having some sort of abnormality in the brain as the casue of the seizure. This can be either a tumor or a vascular malformation. As a result, a diagnostic test – usually a magnetic resonance imaging (MRI) scan – is done to identify the sources of the seizure.
- What happens during microsurgery for an AVM in the brain?
If possible, doctors use precise microsurgical techniques to treat an arteriovenous malformation (AVM) in the brain. They carefully separate the blood vessels of the AVM and block the feeding arteries one by one. The core of the AVM (nidus) is then removed, and the surrounding brain tissue is protected with minimal or no damage to the brain tissue. In removing the nidus, the AVM's draining vein is blocked off and cut. What's left is a small cavity in the brain where the AVM was located, and all the blood vessels coming in and going out of the AVM are thoroughly sealed so there can't be any post-operative bleeding. The blood vessels in the AVM are abnormal, unnecessary blood vessels and don't serve any purpose. They can be removed without disturbing the normal circulation of the brain.
- What is the goal of treatment for an AVM in the brain?
The number one goal of treatment of an arteriovenous malformation (AVM) in the brain is to protect function and quality of life. That means using a treatment with a minimal chance of causing neurological problems like weakness, numbness, speech impairment or other neurological deficits or disabilities. The second goal is to eradicate the AVM completely. The treatment of an AVM in large part is an all-or-none situation. Removing half of the AVM does not reduce the risk by half. In some cases, disturbing the AVM actually increases the risk of future hemorrhage. So treatment has to be complete; the AVM has to be completely eradicated in order to eliminate the future risk of hemorrhage. High-pressure, high-blood-flow arteries send small side branches into the AVM core (nidus), or they directly feed bloodflow into the AVM. The blood then flows out of the AVM through large draining veins. The goal of surgery is to block each individual blood vessel as it goes into the AVM, remove the nidus or obliterate it, block it off completely and preserve circulation in the normal brain blood flow to prevent a stroke in the surrounding brain areas.
- What is the risk of an AVM in the brain rupturing?
The overall risk of initial hemorrhage from an arteriovenous malformation (AVM) in the brain is ~ 1.3% per year. Over a relatively short- and mid-term length of 5 to 10 years, the risk of rupture from the AVM is relatively small, and in some cases, doctors recommend not to treat the AVM at all. AVMs that are located deep in the brain or in the cerebellum (the posterior part of the brain) may have a higher risk of future hemorrhage. Once an AVM has hemorrhaged (bled), the risk of recurrent (repeat) hemorrhage is approximately 5% per year.
- How is an arteriovenous malformation (AVM) in the brain diagnosed?
A brain arteriovenous malformation (AVM) is usually discovered by magnetic resonance imaging (MRI) or computed tomography (CT). These studies can diagnose an AVM incidentally, during evaluation for nonspecific symptoms such as a bump on the head from trauma, generalized headache, or dizziness. Other times, a brain AVM is discovered because of true, associated neurological deficits like speech impairment, stroke-like symptoms, or weakness on one side of the body. These symptoms can be caused by hemorrhage (bleeding) from an AVM that damages an area of the brain, seizure, or “steal phenomenon,” when the rapid flow of blood through the AVM actually prevents necessary blood from nourishing nearby brain tissue. These problems can happen in children, adolescents, adults, and elderly patients. Very small AVMs might not be seen on MRI or CT. A diagnostic cerebral angiogram is often required to discover these very small vascular lesions.
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- What are the symptoms of an arteriovenous malformation (AVM) in the brain?
Arteriovenous malformations (AVMs) in the brain can cause headaches, seizures, focal neurological deficits, and brain hemorrhage, which can be quite serious. When people go to the doctor with an AVM in the brain that's caused a brain hemorrhage, there's often a neurological deficit. This may take the form of a speech impairment, it may be paralysis of an arm and leg, or it may be a coma. About 10% to 15% of the time when an AVM ruptures, the rupture is so severe that the outcome is death. This is a fatal AVM hemorrhage.
- Are arteriovenous malformations (AVMs) in the brain hereditary?
An arteriovenous malformation (AVM) in the brain is like a birth defect of sorts -- almost like a birthmark in the brain. It's congenital, which means it's present at birth, but it's not necessarily hereditary. Only in rare cases is AVM hereditary.
- What is an arteriovenous malformation (AVM) in the brain?
Arteriovenous malformations (AVMs) in the brain are clusters of abnormal blood vessels within the brain that have been present since birth. They're often located on the surface of the brain and sometimes deep within the structures of the brain. They are separate from the brain tissue but within the brain tissue. Any brain area can be affected -- the cerebrum, the cerebellum or the brainstem.
- How is an arteriovenous malformation (AVM) in the brain treated?
If an arteriovenous malformation (AVM) in the brain has caused a hemorrhage, the risk is high enough for another hemorrhage that the AVM should be treated. There are three kinds of treatments: surgery, embolization, which is injecting particles (a glue-like substance) through a catheter to block off the AVM, and radiation therapy, also called stereotactic radiosurgery. With this combination of treatments, the vast majority of AVMs that are dangerous can be treated effectively.
- When is stereotactic radiosurgery recommended for AVMs in the brain?
Stereotactic radiosurgery is used on arteriovenous malformations (AVMs) in the brain that have an acceptable size and configuration for stereotactic radiosurgery, and there is some indication that their future risk is significant. As a general rule, stereotactic radiosurgery is most effective at treating smaller AVMs, and so generally doctors use it for small AVMs that are located in an area where surgery is going to be risky. Small superficial AVMs on the surface of the brain often can be treated with little or no risk surgically, and that provides immediate obliteration to the AVM. However, small AVMs in the depths of the brain or adjacent to critical structures are the ones that are often recommended for stereotactic radiosurgery because there's less risk of surgically induced damage to surrounding areas that might result in neurological problems.
- What are migraines?
Migraine headaches are typically pounding, throbbing headaches. They often occur on both sides of the head but sometimes on one side of the head, and those headaches are typically called sick headaches. Migraine headaches are associated with nausea and vomiting, and they're often preceded by an aura. An aura is an episode, 10 or 15 minutes before the headache hits, when you have some fuzziness in your vision, a blind spot or zigzag lines. In rare cases, people have difficulty talking for a period of time. The aura is then followed by a headache that can last up to six hours or overnight. Very often, people have to go to a dark room. They sleep for a while, and then the headache resolves. Migraine headaches often run in families, so if your mother, a sister or a brother had migraine headaches, then that is probably the diagnosis.
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- What are cluster headaches?
Cluster headache is a miserable disorder that affects both men and women, but usually men. Cluster headaches involve one side of the face, usually in the area around the eye. The episodes can last 30 minutes and up to two hours, and they often come in waves. There are multiple episodes over a period of days or weeks, and then they'll go away for a long period of time. The headaches are often accompanied by redness of the eye, tearing and stuffy nose.
- What is an aneurysm?
Arteries are the high-flow, high-pressure blood vessels inside the head that carry blood from the heart. An aneurysm is a weakened, ballooned-out spot in a brain artery. We don't fully understand how the original weakness in the blood vessel first develops. It is possible that people are born with a slightly weakened spot in a brain blood vessel, and a variety of risk factors determine whether that spot develops into an aneurysm. Most commonly, an aneurysm forms at the branching point of two arteries. With a lifetime of blood pressure pounding away on that weak spot, it gradually expands and forms an aneurysm. Once it weakens sufficiently, it can cause a hemorrhage. Further research is needed to better understand this process.
- I was just diagnosed with a brain aneurysm, what should I do next?
The initial diagnosis of a brain aneurysm is often done when your primary care doctor or neurologist orders a magnetic resonance angiogram (MRA) or computed tomography angiogram (CTA). Once the diagnosis is made or there is suspicion that you have a brain aneurysm, then you should be evaluated by a specialist with expertise in managing and treating brain aneurysms. A cerebrovascular neurosurgeon is a neurosurgeon who specializes in blood vessel disorders of the brain and spine, including brain aneurysms. A comprehensive (or dual-trained) cerebrovascular neurosurgeon has extensive expertise in both open surgery (craniotomy for aneurysm clipping) and endovascular treatments (coiling, stents, flow diversion, etc). Your doctor will then provide you with the appropriate counseling and next steps for your aneurysm.
- What doctor should I see to evaluate my brain aneurysm?
Choosing a doctor to evaluate and treat a brain aneurysm is an incredibly important process. Brain aneurysms are treated by neurosurgeons, interventional neuroradiologists, and interventional neurologists. Each of these specialists comes from a different training background. Dual- or comprehensively-trained neurosurgeons perform both open surgical and endovascular procedures to treat brain aneurysms. Interventional neuroradiologists and neurologists perform endovascular treatments.
- Can pregnancy or childbirth cause an aneurysm to rupture?
There are medical risks associated with pregnancy under the best of circumstances, so it's logical to think that the possibility of a rupture might be higher if you have an intracranial aneurysm. Unless the aneurysm is extremely fragile, very large, or has ruptured before, a small aneurysm discovered during pregnancy can probably be managed with careful monitoring. In cases where you do have a large or fragile aneurysm or one that has previously ruptured, it would be a good idea to have a C-section rather than go through the straining and pushing associated with a normal delivery.
- Is there any connection between lupus and aneurysm rupture?
Lupus affects a variety of tissues. While lupus can cause inflammation of brain arteries, it tends to affect smaller blood vessels in the brain, not the larger ones where aneurysms rupture. Because of that, it can't be said that there's a strong connection between lupus and intracranial aneurysm ruptures, although theoretically it is possible.
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- What if the surgeon is unable to coil the aneurysm?
Coiling is a technique by which a catheter is introduced into an artery of the body (most commonly the femoral artery in the leg), passed up through the arteries of the body, inside the head, and into the aneurysm. The aneurysm is then packed off from the inside with wire coils. These are very pliable, soft coils made of platinum that are specifically designed to be placed in aneurysms. In some circumstances coiling of an aneurysm cannot be accomplished. This can be due to the size/shape of the aneurysm, its location on the blood vessel, normal blood vessel branches that might arise from or near the aneurysm, and the tortuosity (twistiness) of the arteries. If coiling of an aneurysm cannot be done safely, then alternative treatment types can be excellent options. Surgery for aneurysm clipping or potentially other endovascular techniques (flow diversion) are possibilities.
- How should I treat headaches if I am being monitored for an aneurysm?
Tylenol is recommended for headaches when being monitored for an aneurysm. Tylenol doesn't have an interaction with blood clotting; it doesn't seem to affect intracranial arterial vessels at all. Ibuprofen, Advil, or Motrin are also reasonable choices. They are very mild platelet inhibitors and blood thinners. In somebody who has a propensity for bleeding or who has ever had a hemorrhage inside the head, ibuprofen is generally not recommended. For someone with an unruptured aneurysm, if ibuprofen is absolutely required to control the headaches, the risk is probably pretty small. Most prescription medications for migraine type headaches are also ok to take. However, some over the counter medications, such as Excedrin, contain Aspirin. Aspirin has strong anti-platelet properties, and you should consult with your doctor if you have a brain aneurysm and wish to take medications that contain Aspirin.
- Do I need to take medications if my aneurysm has been treated with a stent?
Patients who have a stent in their artery often have to be on a mild blood thinner (anti-platelet medication) for a minimum of several months, and in some cases long term, since the stent itself can trigger blood clotting. How does this happen? Platelets will collect on the stent, forming a clot. If it gets washed off and travels downstream in the brain arteries, it can cause a stroke. That's why people who have a stent usually have to be on anti-platelet medication. That typically means aspirin or Plavix, or aspirin and Plavix together. Taking those medications is important. Stopping them without the advice of your doctor can be dangerous in an aneurysm that has been treated with stenting.
- What happens when someone goes to the emergency room with an aneurysm?
When someone goes to the emergency room with an aneurysm and symptoms of a possible aneurysm rupture, a computed tomography (CT) scan is typically done. A CT is an excellent means for detecting blood that might have leaked out from an aneurysm. If leakage is evident, further testing is done to identify the location of the aneurysm, and treatment begins so that the aneurysm doesn't bleed again. When a patient has had what appears to be the rupture of an aneurysm, is it bleeding at that moment in time? No, it's not. The aneurysm bleeds for a few seconds, then seals itself off. A clot forms at the top, closing the hole. In this case treatment is necessary to seal the aneurysm so that a second hemorrhage, which is almost invariably fatal, doesn't occur. If the aneurysm did not seal itself off and the bleeding is ongoing and continuous, the patient is dead on arrival. That is universally a fatal event.
- Is there a relationship between migraines and intracranial aneurysms?
There is no evidence that a single migraine headache or even frequent migraine headaches over a period of years increase the risk of having intracranial aneurysms. The interaction comes between distinguishing between a migraine headache and the type of headache associated with the rupture of an intracranial aneurysm. People who have migraine headaches recognize them as migraine headaches. A severe, sudden, unusual headache – one that comes on very rapidly and is on one side of the head – is a dangerous headache that should be evaluated as quickly as possible. Other signs of a possible aneurysm rupture are severe neck pain and any neurological problems such as impaired speech, weakness, stumbling or a collapse. That is not a migraine; it's a medical emergency. A sudden dilated pupil in one eye or difficulty moving one eye can also be a sign of a potential ruptured or rapidly enlarging aneurysm.
- Does taking an aspirin every day prevent an aneurysm from rupturing?
There is no medicine or pill that can definitely prevent an aneurysm from growing or rupturing. There is, however, evidence from some clinical studies that medications people take to reduce inflammation in other parts of the body might also reduce the risk of rupture of an intracranial aneurysm. In one recent study patients who took a mini-dose aspirin, a baby aspirin or a single aspirin every day for its protective effect against atherosclerosis seemed to have a lower risk of rupture for intracranial aneurysms. That doesn't mean that people with aneurysms should start taking an aspirin every day – it's usefulness for preventing hemorrhaging is still being investigated, and this decision should be discussed with your doctor. Over the next few years the relationship between arterial inflammation and the risk of intracranial aneurysm rupture may be clearer.
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- Are roller coasters safe if I have been treated for an aneurysm?
The risk of riding rollercoasters is unknown in people with an aneurysm. For most people the risk is probably quite small. If you have an untreated aneurysm, doctors generally recommend to avoid very strenuous or extreme activities. If you have a treated aneurysm, you should discuss with your doctor whether or not you have activity restrictions.
- Is air travel safe if I have been treated for an aneurysm?
High altitude and air travel seem to pose little risk. There are some changes in external pressure within the cabin, but that gets equalized quickly throughout the body. People with treated aneurysms are often cleared to travel on an airplane by their doctor.
- Are yoga inversion postures risky if I have been treated for an aneurysm?
People with an untreated aneurysm should avoid extreme inversion yoga postures for prolonged periods of time because the risks to an aneurysm remain undefined at this point. There's plenty one can do in a yoga class without inversion, so it's best to avoid these poses.
- Do I have to change my lifestyle if I am diagnosed with an aneurysm?
Patients with an aneurysm generally don't have to change their lifestyle in any significant way. You do have to be more diligent about your cardiovascular health and should be checked for hypertension (high blood pressure). If you smoke, it's critical that you stop. Cigarette smoking damages blood vessels in the heart and brain. It weakens aneurysms and causes them to grow, increasing the risk of a rupture. Excessive alcohol intake and illicit drug use (such as cocaine) also increase risks of an aneurysm. In terms of exercise, avoid extreme exertion to the point where you're at the maximum level of intensity. Do avoid contact sports, such as boxing and football; this isn't an issue for most people. If you have an untreated aneurysm and feel that your life is too restricted, then it is best to discuss possible treatment options with a brain aneurysm specialist.
- Do endurance sports increase the risk of aneurysm rupture?
Most cardiovascular sports don't raise the blood pressure to an extreme degree. Therefore, they likely don't increase the risk of aneurysm rupture. However, high spikes in blood pressure can put additional stress on the blood vessel and aneurysm wall, increasing the risk of aneurysm rupture.
- What are the newest treatments for aneurysms?
Treatments for brain aneurysms are constantly being improved. These improvements come from both new tools (devices) to close the aneurysm and new techniques to perform the treatment in a less invasive and safer way. New endovascular devices designed to close the aneurysm are numerous and include advanced coils, modern stent-technology, flow diversion, and intra-saccular flow disruption. There are also significant improvements in the catheters that track through the blood vessels to deliver these therapies to the aneurysm. For open surgery (craniotomy), various advances have been made to clip the aneurysm through a smaller window in the skull. These advances include improved imaging of the blood vessels, more precise techniques to remove less bone of the skull, and intra-operative monitoring of brain activity. If you have an untreated brain aneurysm, it is best to discuss treatment options with an expert who has knowledge of all of these advances.
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- Why are follow-up tests important after aneurysm treatment?
Follow-up is important after an aneurysm treatment. Diagnostic tests are recommended to confirm that the aneurysm remains closed over time and that it is not trying to regrow. Some treatments have better durability than others, and the recommendations for follow-up imaging will depend on which aneurysm treatment is performed. Surveillance diagnostic imaging may also be recommended to monitor for the growth of a new aneurysm in a different location.
- Why aren’t all aneurysms treated with aneurysm coiling?
The shape of the aneurysm, its location, and the age and medical history of the patient are all factors that determine whether we select endovascular techniques (coiling or flow diversion) or aneurysm clipping for treatment. In terms of shape, aneurysms most successfully treated with coiling have a narrow neck that will hold the coils in place. Coils are packed into the aneurysm and essentially seal off the opening, or what we call the neck of the aneurysm. If the aneurysm has a wide neck or is large in size, the packing of the coils may not be optimal. In this scenario, placement of a stent might be needed to hold the coils in the aneurysm. Other good options include microsurgical clipping and possibly flow diversion.
- What is aneurysm coiling?
Coiling is a minimally-invasive endovascular technique to treat an aneurysm. A small catheter, called a micro-catheter, is passed inside the blood vessels of the body and into the aneurysm. Once inside the aneurysm, very small platinum wires called coils are threaded into the body of the aneurysm, referred to as the “aneurysm dome.” The coils often form a ball-like structure, called a “coil pack.” It is up to the doctor doing the procedure to select the type and size of the coils used as well as to carefully position the coils in the aneurysm. Once in the aneurysm, the coils interact with the blood and form a blood clot. It is the combination of the coils plus the blood clot within the aneurysm that prevents blood flow into the aneurysm and prevents the thin, weakened wall of the aneurysm from rupturing. The goal of the treatment is to have the coils stay in the aneurysm and not migrate into the normal vessel that the aneurysm arises from, called the "parent vessel." In some circumstances, particularly for aneurysms with a wide-neck (opening), a stent or balloon is used to help hold the coils in the aneurysm and prevent them from falling into the normal blood vessel. Coiling technology is constantly evolving, with new classes of coils and new catheter delivery systems. Many aneurysms, but not all aneurysms, can be treated by coiling, you should discuss with your doctor whether coiling is an appropriate treatment for your aneurysm.
- Are there problems with aneurysm clipping?
The problem with aneurysm clipping is that it is not minimally invasive. It requires a craniotomy, opening a window in the bone of the skull, going in and working under the base of the brain and then applying the clip.
- How are brain aneurysms treated?
The traditional treatment is called aneurysm clipping. A craniotomy is performed, opening a window in the bone of the skull. A surgical microscope is used to locate the aneurysm, then microsurgical techniques are used to close it off with a spring-loaded clip. The clip squeezes the aneurysm closed and seals it at the level of the normal blood vessel. This prevents blood from getting into the aneurysm and eliminates the risk of a hemorrhage. This is a very well-established and durable technique that has been used routinely since the 1960s. Once an aneurysm is treated by clipping, the risk of the aneurysm regrowth or bleeding later is extremely small – 1% or less. Once sealed, blood can't get into the aneurysm and a rupture isn't possible. Endovascular techniques, or minimally invasive techniques performed from the inside of the blood vessel, were developed to treat aneurysms in the late 1980s. These treatments, of which aneurysm coiling is the most common, have gained significant popularity since their introduction because they are minimally-invasive with rapid recovery of the patient. A newer endovascular treatment option includes a technique called flow diversion. This involves placement of a special high-mesh density stent across the neck of the aneurysm. Over time, the inner lining of the blood vessel wall grows onto the stent and heals the blood vessel. This vessel reconstruction closes off the opening to the aneurysm effectively reconstructing the blood vessel wall. It is best to speak with an aneurysm expert to learn more about these treatment options and what is the most appropriate option for your aneurysm.
- How do doctors keep an eye on aneurysms?
Non-invasive imaging techniques can be used, usually a computed tomography (CT) angiogram or a magnetic resonance (MR) angiogram with intravenous contrast injection. A three-dimensional image of the aneurysm can be generated. The size can be measured carefully to see if it develops any irregularities in shape. These features will help determine whether an aneurysm is enlarging, weakening, and headed towards a rupture. This method of monitoring is called conservative therapy, non-operative treatment, or watchful waiting. A certain percentage of aneurysms will gradually grow bigger over time. However, an aneurysm does not have to grow bigger before it ruptures. Inflammation is thought to play a role in the thinning/weakening of the aneurysm wall. It is possible that the aneurysm wall can thin out to the point of breaking before the aneurysm grows to a particular size. For this reason, careful evaluation of an aneurysm by a specialist is recommended to determine the risks and rewards of monitoring versus treatment.
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- What factors increase the risk of an aneurysm rupturing?
Risk factors for aneurysms are split into 2 major categories: modifiable risk factors and non-modifiable risk factors. Modifiable risk factors include those things that can be treated, changed, or prevented by a person. These include cigarette smoking, hypertension (high blood pressure), excessive alcohol use, and use of certain drugs (such as cocaine). Non-modifiable risk factors are those things that an individual cannot change, and these include family history of aneurysms or subarachnoid hemorrhage and certain genetic conditions or syndromes (such as polycystic kidney disease, Ehlers-Danlos, and Marfan’s).
- Are some aneurysms riskier than others?
Aneurysms located on certain blood vessels are exposed to higher stress from the circulation of the blood. The posterior aneurysms – those located towards the back of the brain on the posterior communicating artery, on the basilar artery – are the ones that are thought to be at higher risk of rupture. Size also makes a difference. A small aneurysm is one that is less than seven millimeters in size – that's significantly less than a half inch. Smaller aneurysms are thought to have a lower risk of rupture than larger aneurysms. However, small aneurysms can still rupture, and patients with ruptured small aneurysms frequently present to major hospitals for treatment.
- When are aneurysms dangerous?
Aneurysm size, shape, and location are important factors in determining the rupture risk. In general, the larger the aneurysm, the higher the risk of it rupturing. Smaller aneurysms are thought to have a lower risk of rupture than larger aneurysms. However, small aneurysms can still rupture, and patients with ruptured small aneurysms frequently present to major hospitals for treatment. Each aneurysm should be evaluated by a specialist to determine its risk of rupture.
- What are the symptoms of an aneurysm that has ruptured?
The main symptom of a ruptured, or hemorrhaged, aneurysm is a sudden, severe headache. People often say it's the worst headache of their life. Or they may describe the feeling of something tearing inside their head. It is a very dramatic event. Other related symptoms include severe neck pain and any neurological problems such as impaired speech, weakness, stumbling or a collapse. We don't want to wait until someone has a hemorrhage to treat them because 50% of the time the patient becomes disabled or dies as a result of the hemorrhage. Anyone experiencing these symptoms should seek immediate medical help.
- What is endovascular treatment for an aneurysm?
Endovascular treatment is a minimally-invasive treatment performed on the inside of the blood vessels. Most commonly, the procedure is performed by inserting a catheter (flexible tube) into the femoral artery at the top of the right leg. The catheter (or multiple catheters) is then navigated inside the blood vessels of the body, up to the head, and to the blood vessel from the aneurysm arises. Once the catheter is in position, a treatment can be performed using the device (coil, stent, etc.) that is chosen. Endovascular treatment does not require an incision like open surgery.
- How do I decide which aneurysm treatment is best?
The decision to treat an aneurysm and the choice of the treatment modality (type) is a highly individualized and customized process. Each person with an aneurysm is carefully evaluated with regards to overall health, characteristics of the aneurysm, and the risks of all treatment possibilities. All of these factors are carefully taken into consideration before the doctor makes a recommendation. A person with a brain aneurysm should be evaluated by a trained specialist in brain aneurysms and their treatments.
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