Explaining All of the Options for AVM: Cerebral Arteriovenous Malformation

Transcription

1 Explaining All of the Options for AVM: Cerebral Arteriovenous Malformation Recorded on: November 19, 2012 Bernard Bendok, M.D. Director of the Neurointerventional Program Northwestern Memorial Hospital Please remember the opinions expressed on Patient Power are not necessarily the views of Northwestern Memorial Hospital, its medical staff or Patient Power. Our discussions are not a substitute for seeking medical advice or care from your own doctor. That s how you ll get care that s most appropriate for you. Hello and welcome to Patient Power sponsored by Northwestern Memorial Hospital. I m Andrew Schorr. Well, imagine you had the worst headache of your life or perhaps suddenly you had a seizure or there was even a bleed in your brain. It could be something called an arteriovenous malformation, or an AVM, perhaps a malformation that started when you were developing as an infant in your mother s womb. A leading expert in the treatment of AVMs at Northwestern Memorial Hospital is neurosurgeon Dr. Bernard Bendok. Dr. Bendok, help us, in your words, what is an AVM? Arteriovenous malformations are congenital lesions. They form before a person is born, typically. They consist of feeding arteries, draining veins and a collection of abnormal vessels that are usually thin-walled and are prone to rupture. They can occur anywhere in the brain. How would someone know if they have an AVM? Well, many AVMs can be silent, and they are typically not found until the symptoms occur, although increasingly many are found during the work-up of other, unrelated complaints. The most common presentation of an AVM when it s symptomatic is brain hemorrhage that can be

2 either mild, moderate or very severe and potentially life threatening. Seizure is the second most common form of presentation. Headache and stroke symptoms can also be associated with an AVM. If someone has an AVM, what do you do about it? Well, whenever a patient has an AVM, the most important first goal is to stabilize the patient and to make sure that the presenting problem that an AVM causes is dealt with in a way that will minimize harm to the patient. If an AVM causes a brain hemorrhage the first goal is to determine where the hemorrhage came from and to manage the patient through that potentially difficult period where brain swelling can occur and other parts of the brain can be affected by the brain hemorrhage. If an aneurysm has caused a brain hemorrhage it s important to consider the treatment of that aneurysm to prevent another hemorrhage. If no obvious source of the bleeding is found other than the overall AVM, then the hemorrhage is typically managed medically, although sometimes if the hemorrhage is large, surgery to take out the blood clot may be needed to help the patient. Dr. Bendok, at Northwestern how do you investigate an AVM to see what needs to be done? Well, if a patient comes in very sick from a hemorrhage the first line of imaging is typically a CAT scan. Beyond that, vascular imaging is needed to determine the vessel anatomy of an AVM, and that can start with a CT angiogram. Usually an invasive diagnostic angiogram is needed to define the exact architecture of an AVM and to better understand how blood is flowing through it but also to look for an aneurism and to understand potential risk factors that are seen in the vessels either feeding the AVM or draining the AVM. Maybe somebody is going to have pills, maybe somebody is going to have radiation or surgery. What s the discussion with a patient as to whether something needs to be done and what that is? Initially the most important thing is to make sure that any life-threatening issues are dealt with. If there s a big hemorrhage, that hemorrhage may need surgery to protect surrounding areas of the brain and to prevent a potentially catastrophic outcome. Seizures have to be controlled, so that s another important issue. 2

3 Beyond that, and once the patient is stabilized, one can start to think about long-term prevention. Typically when a hemorrhage occurs from an AVM we like to wait several weeks and sometimes several months to allow the brain to recover from the hemorrhage and then we start discussing potential treatment options for the patient. Dr. Bendok, where are we now with current treatments for AVM? Treatment options for AVM have come a long way in the last several decades, and they continue to evolve in positive ways, in my view. The modalities that we consider when we are considering treatment for AVM are microsurgery, radiosurgery, and embolization. These modalities are either used alone or in combination. The more complex an AVM the more likely it is that we will be using more than one modality to treat the AVM. Take us through the different modalities for treatment that you have for AVM. Microsurgery is essentially the use of microsurgery techniques, and what that means is the operating microscope and micro instruments to remove an AVM. It is a curative procedure. The key is to select the right AVM and the right patient for that treatment option. Oftentimes embolization is performed before surgery to make the surgery safer and easier, and sometimes one embolization is needed, sometimes more than one embolizations can be needed to make the surgery safe and effective. Embolization is another modality that is either used alone or in combination with other modalities. Embolization is a procedure where we use small catheters that we can navigate into the brain vessels working all the way from the leg arteries up into the brain vessels. We do that fluoroscopically. Through those catheters we can better understand the microanatomy of an AVM and potentially inject embolic materials to treat the AVM. We can inject glues that have been approved by the FDA for shrinking an AVM, decreasing the blood flow through an AVM. That potentially can be curative in some cases. In some cases it is done as a way to make microsurgery safer and easier. Radiosurgery is another important modality we have to treat AVMs. Radiosurgery is the use of radiation in a very focused way to shrink an AVM over the course of two to three years. For the right kind of AVM it can be the best option. We typically use radiosurgery radiation for AVMs that 3

4 cannot be treated with open surgery. For example an AVM in a deep part of the brain that would be dangerous to get to surgically, radiosurgery can be an excellent option. We also occasionally use radiosurgery for very complex AVMs that cannot be treated any other way. We sometimes use it in a staged fashion. In other words, we can use radiosurgery over multiple sessions to treat AVMs that would otherwise be untreatable. Dr. Bendok, where are we headed in research? There are a number of exciting areas that we are pursuing on the research front with regard to AVMs at Northwestern. First, there is the very important area of predicting which AVMs will need treatment and which ones don t. And part of the answer on that front is better understanding the risk factors. Many of those risk factors can potentially be seen on imaging. Historically, our imaging studies were not precise enough to shed light on this issue. There are many exciting advances in MR technology that are starting to show more details about AVM hemodynamics, AVM microarchitecture that could potentially shed light on things that we need to know about with regards to how AVMs behave. Molecular imaging is an exciting front. One of the vexing questions when it comes to AVMs, why does an AVM remain quiet for decades and all of a sudden rupture? We suspect that something biological is going on in an AVM, but we don t have great tools yet to understand that biology. It is my prediction that molecular imaging and advanced MR imaging will shed light on those questions over the next decade. Two other areas of active research are determining more precise measures of clinical and qualityof-life outcomes for patients with AVM. It is one of our major goals at Northwestern to determine what will give people the best outcomes and the best quality of life, and over time we are looking for ways to become wiser as to how we advise patients regarding which treatment modality will give them the best possible outcome. Dr. Bendok, if somebody has a headache is it too much coffee or could it be an AVM? How do you know? Headache is a very common complaint. It s a very common problem. Some headaches are benign, but occasionally headaches can signify something very serious going on in the brain. If a 4

5 person has a headache that is very atypical of their usual headaches they should seek immediate medical attention. The most worrisome type of headache is a headache that starts out as a very severe headache out of the blue, what we call thunderclap headache. If someone has the worst headache of their life and it starts without any warning, that is a very dangerous and serious headache until proven otherwise. A person who has that type of headache should call 911 and seek immediate medical attention because that type of headache could signify a brain hemorrhage that theoretically could be due to an aneurysm or an AVM. When you put it all together with all the tools you have, if someone has an AVM, what is their hope for their future? I am more hopeful than ever that we have outstanding tools for patients with AVMs, tools that can help them achieve safety for their future, and a better quality of life. On the medical front our ability to control seizures and treat seizures is better than it s ever been. On the surgical front our microsurgical techniques have evolved dramatically over the last decade, and I think we are wiser at selecting patients for that modality, and with advances in neuroanesthesia and microsurgical techniques I think our outcomes are improving. On the embolization front, our imaging modalities, our catheters and our agents that we use to embolize an AVM are better than ever. With radiosurgery our technology has also evolved in many positive ways. We are more precise in the way we deliver radiation. We much better understand today which patients do better with radiosurgery and which ones do not. Overall our wisdom factor has increased over the last 10 to 20 years so we can better match patients with the modality and treatment that is going to be best for them specifically. Having an AVM sounds like it s a serious business. Would you advise that someone see a specialist, see a specialized team in the field to bring all that knowledge together for them? Absolutely. Increasingly healthcare is becoming multidisciplinary. It s very important that a patient with an AVM seek advice from a team of physicians who have expertise with medical management of seizures and brain hemorrhage, surgical expertise in microsurgery, endovascular expertise and radiosurgery expertise. The makeup of that team varies from center to center, but it s very important that a patient be seen at a center that specializes in treating brain AVMs. 5

6 Dr. Bernard Bendok, thank you for being with us on Patient Power. Once again, thank you for your devotion to patients with AVMs, and good luck with all your research and pioneering in the field. In Chicago for Patient Power and Northwestern Memorial Hospital, I m Andrew Schorr. Remember, knowledge can be the best medicine of all. Please remember the opinions expressed on Patient Power are not necessarily the views of Northwestern Memorial Hospital, its medical staff or Patient Power. Our discussions are not a substitute for seeking medical advice or care from your own doctor. That s how you ll get care that s most appropriate for you. 6