As many as 1 in 20 people develop a dangerous bulge in a brain artery, often revealed incidentally by neuroimaging, so PCPs need a solid grasp of the first steps in evaluation. This presentation from neurosurgeon Ethan A. Winkler, MD, PhD, offers data-driven guidelines on assessing a patient's risk, covering factors that range from alcohol consumption and family history to the location, size and shape of the aneurysm. Winkler also covers treatment options, how to tailor the strategy to the individual patient and when to refer.
It's my absolute pleasure and, and thank you very much for having me and and good afternoon everyone. My name is Ethan Winkler. I'm an assistant professor as well as a director of the Vascular Anomalies and stroke Computation lab at U CS F. Um by way of introduction, I'm a dual trained neurosurgeon who specializes in the the spectrum of cerebrovascular pathologies, meaning that I treat patients both with endovascular therapies as well as open surgical approaches and the focus of today's talk is gonna be on aneurysms. Um more specifically a primary care physicians approach to brain aneurysms. And I hope to present a synopsis of kind of data driven guidelines. So over the course of the next 20 minutes, I'm gonna introduce what brain aneurysms are and what causes them to develop. And then I'm gonna provide kind of a high level overview of evidence based guidelines that aid us in deci in treatment, decision making. Once again, keeping this in mind of the intended audience, a lot of situations that you face in an outpatient clinic, really focusing on unruptured aneurysms. So cerebral aneurysms are actually present in about 3 to 5% of the population So one in 20 to 1 in 50 people, um they are out poaching that occur most commonly at vascular branch points and they form structures that kind of appear to be like balloons. In about 20 to 30% of patients with aneurysms, you can actually find multiple aneurysms. And what is believed to cause these to form is kind of the the wear and tear that we experience over the course of life. Um In the setting of a genetic predisposition and at a cellular level, our normal arteries are consistent of multiple layers of cells where you have an endothelial cell lining, that lines the lumen of the blood vessel in which blood flows. These are then surrounded by smooth muscle cells which provide much of the structural support to the blood vessels. And then this is further in sheath by kind of an adventitial layer form of formed by fibroblasts. And because of these combination of both the environmental stresses that we experience over the course of life, as well as some genetic predisposition. We now know that we start seeing dysfunction in multiple layers of these. More specifically, we notice that endothelial cells start to become denuded or start to become abnormal. And then these structural support cells um start to become depleted and this catalyzes kind of the formation of these weak spots or out poaching that result in brain aneurysms. There's also a link between the neuro inflammatory response and it's believed that infiltration of immune cells, then further catalyzes these events and also causes sometimes aneurysms to progress meaning to grow or the most feared complication is when an aneurysm actually grows to the point in which it burps. And this classically results in subarachnoid hemorrhage, which I defined to my patients as a severe form of stroke. It's also a leading cause of sudden death. About a third of patients don't make it to the hospital when this occurs. A third of patients are severely disabled and about a third of patients do. Ok. Um These are just an example over here on the right side of the screen of a classic CT scan kind of showing this kind of starfish pattern, showing blood within the subarachnoid space. And when this occurs, it rises in the pressure inside of um the brain as well can lead to delayed sequela such as vasospasm in which the blood vessels actually spasm or become smaller that can result in delayed ischemic strokes called delayed cortical ischemia, as well as kind of um clogging the normal pathways of the cerebral spinal fluid circulating in our heads, resulting in a condition called hydrocephalus. But it's important to recall that not all aneurysms bleed and we'll get into some of the risk factors that may once an incidental aneurysm has been discovered in an unruptured setting, um predispose it to potentially being more aggressive in its course risk factors for cerebral aneurysms. And these are important things that I take in in a clinical history, um include family history, um which is defined as having at least one first degree relative with aneurysms or subarachnoid hemorrhage. Um I should indicate and one of the most common questions that I get is when is it appropriate to screen? And right now, our guidelines suggest that it's most important to screen patients for intracranial aneurysms with either ac T angiogram or Mr angiogram when there's two or more first degree relatives, other important things to consider are the presence of comorbidity, such as hypertension, atherosclerosis, advancing age, um and special populations that have collagen vascular disorders such as er Danlos or Polycystic kidney disease with respect to social history. Once again, going back to the kind of environmental factors that can contribute to aneurysm format formation as well as growth include cigarette smoking, illicit drug use, specifically those of cocaine and methamphetamine as well as ex excessive alcohol consumption. So for the initial work up on brain aneurysms, it's important to remember in many instances, these are clinically silent um until they come to detection with either cranial neuropathies or a sudden severe headache. But the overwhelming majority of patients are usually asymptomatic and that these are detected on, on imaging for other purposes with respect to headaches. A lot of patients undergo imaging because they have chronic headaches. But we don't believe that the aneurysms actually leads to these chronic headaches, but rather sudden severe headaches when they're starting to to either bleed or subtly bleed. So there's a concept known as a sentinel hemorrhage, which is a very small hemorrhage that cannot be normally detected on imaging. But is this sudden severe headache. So if any of your patients ever have sudden severe headaches and an aneurysm is detected that should prompt a more urgent evaluation. Our choice of imaging modality as include both CT based as well as Mr based angiography And I actually have a couple just representative pictures up here of AC T angiogram as well as an Mr angiogram um showing actually in the same patient, an aneurysm of the left internal carotid artery which is located kind of over in here. Um And they're very comparable with respect to their sensitivity and specificity with this. Um So a lot of times my selection as far as imaging modality is driven based off of whether someone would tolerate a longer scan for an Mr based technology, whether it's a younger patient and we're trying to limit radiation um exposure, but both are are fairly comparable in their um accuracy. The gold standard still remains to be diagnostic, cerebral angiography, which will talk about a little bit more on how I utilize that to better characterize um aneurysms that are, you know, looking very borderline for treatment or ones that I intend to treat. And I think that this is just a nice representative example of showing you the kind of level of information that we can obtain with both of those studies or with all of these different studies. Ct and Mr based um technologies um really offer kind of a broad high level overview on whether an aneurysm is present. They perform better with larger aneurysms, usually over five millimeters than smaller aneurysms. And then diagnostic cerebral angiography, which is performed as an outpatient procedure really helps us develop a high level of granularity and view where we can really appreciate subtle irregularities in that aneurysm, getting very precise measurements and so forth. And when you're looking at ac T angiogram or reading a report, some of the basic information to derive from that includes the location of the aneurysm. So at the base of all of our brains, we have a vascular structure or an anastomotic loop called the circle of Willis that's composed of two internal carotid arteries as well as two vertebral art vertebral arteries which then converge into a Basler artery and common locations in which we see aneurysms. Although they can arise from any one of these arteries within the brain include the anterior communicating artery which connects both of the anterior cerebral arteries, the middle cerebral artery, the posterior communicating artery, as well as the basilar artery itself. And besides the location of the aneurysm, a basic appreciation of size because that's heavily involved in some of our treatment decision making. Usually one dimension is sufficient and we usually just choose the largest dimension of the aneurysm to report its size. Although a three dimensional appreciation is important, whether the aneurysm is a smooth balloon or whether we actually see some daughter lobules or subtle signs of irregularity and then also kind of the morphology of the aneurysm. So the most common aneurysm when I'm talking about these balloon like structures that occur at branch points are saccular aneurysms. But there are other variations in this such as fusiform au aneurysms, which mean just kind of a dilation of a blood vessel dissecting aneurysms or rarely this condition called Dula Aasia, which is just this fusiform dilation with superimposed aneurysms, sometimes that are formed on these blood vessels. Now, with respect to our treatment options, any time that I see a patient with an aneurysm, I explain that there's really three treatment options that will go into in later slides observation. Uh meaning that we're gonna repeat annual scans, endovascular embolization, which is a minimally invasive procedure that I'll describe a little bit more or open surgical clipping. Um in order to to definitively uh remove the aneurysm from the circulation. But before I go into this, one of the challenges with aneurysms is proper patient selection for potential treatment or observation. And in order to accomplish this, you know, we adopt a holistic view um incorporating patient specific factors, aneurysm morphologic factors. And then of course, how heavily um psychosocial factors and how carrying this diagnosis is affecting the patient. So I just want to present to you two kind of treatment decision making algorithms that have been data driven that are out there for factors that are important to at least appreciate on um on a patient history. And it's important to remember that most aneurysms don't bleed. Most aneurysms actually don't grow. So this is just one example of one of these treatment algorithms that we use to decide whether or not we're crossing over the threshold to actually treat an aneurysm or it's an aneurysm that poses a higher risk. And this is called the phases score, which is just an acronym to uh that incorporates the different variables that it um that it uses to make these calculations and what it stands for is patient demographic or population. That's the P um And that we now know that certain ethnic backgrounds pose a greater risk for aneurysms, taking a more aggressive course, the presence of untreated or treated hypertension, the patient's age, the size of the aneurysm, whether they had had a bleeding event from a prior aneurysm and then the location or site of the aneurysm. And as we can see here, when we add up these, this scoring rubric, we see wide variations in the natural history of aneurysms ranging from less than 1% all the way up to about a risk of rupture of 18%. And it's important to point out that these risks are a five year cumulative risk factor for the aneurysm potentially presenting an issue. This isn't the only scoring rubric that's available to you clinically to help kind of stratify some of these decisions. There's another one that's much more complicated called the unruptured intracranial aneurysm treatment score, which was actually designed based off of a del Delphi um consensus approach that as you can see here um incorporates a number of other variables and to just highlight a couple others that I think that are most salient to add to your clinical history taking is the family history component, current cigarette smoking, current drug abuse, as well as whether or not on radiographic studies, radiologists or if you interpret your own scans, comment on any irregularity or lobulation of the aneurysm. And also if there's multiple scans available, whether there's aneurysm growth or de novo appearance of an aneurysm because that may port trend to a more aggressive course. And I realized that this amount of information can sometimes be overwhelming. So I wanted to kind of synergize this for the ones that I feel are most important that the patient specific factors that I would definitely touch on if possible is the history of a ruptured aneurysm within that same patient. Because a lot of natural history studies have suggested that other aneurysms in that same patient may portend a more aggressive course. Once again, hypertension smoking drug use and heavy ethanol abuse as well as aneurysm factors. So a lot of the natural history papers that have gone the that have followed aneurysm serially have suggested a size threshold of about seven millimeters of guiding treatment decisions. However, there's a caveat to that because actually the majority of ruptured aneurysms that we see in the the in the inpatient setting are actually those that are less than seven millimeters. And why we can't rely heavily on just a single variable. We also know that there's higher risk locations of where the aneurysms arise, such as the basilar artery, the anterior, as well as posterior communicating artery, presence of irregularity such as daughter lobules or other kind of lumps and bumps on the aneurysm. And whether or not there's been any interval, growth in patients that have serial scans. And I commonly get asked as to when to refer a patient with, with um aneurysms to a specialist such as myself. And you know, there's not really any great data driven guidelines as to when we cross that threshold for referral or what, um or when this can just be conservatively managed in a primary care physician's um office, but several, you know, things that have come to mind and these are just my opinions. Um are, is certainly any patient that has had a prior subarachnoid hemorrhage from a ruptured aneurysm, any aneurysm that's three millimeters or higher, especially if there's a regularity noted, or if there's some of these multiple risk factors that I described on my previous slide present. However, I completely appreciate the fact that a lot of patients become very frightened and anxious um when they receive a diagnosis from of aneurysms. And this little table that I have up here is actually from one of my partner's um publications that have shown that the diagnosis of aneurysm um is heavily associated with a lot of um mood disorders such as PTSD depression, generalized anxiety disorder. And I've adopted the philosophy that I am happy to see any patient with any aneurysm because there's a huge psychosocial component to this. And sometimes just even knowing that they have me available, helps provide patients with a little bit of security and helps ease some anxiety. So I'm always happy to talk um to any patient at any time. Now, in what kind of goes on and on my side of things is, is really trying to stratify patients based on predicted risk into kind of three treatment options. Once again being observation, endovascular embolization and then open surgical treatments. And I'm just gonna kind of superficially go over how I make some of those decisions to hopefully make my clinical reasoning a little bit more transparent. So for patients that, that I deem to be appropriate for observation, usually, meaning that there's an absence of risk factors, it's a small aneurysm. The patient is not overwhelmed by the diagnosis to the point of it being disabling in their life. I prefer to repeat CT or Mr angiograms annually. So once a year, it gives us a chance to, to touch base again. And what I'm looking for is any changes in size uh of the aneurysm or morphology. We now have a lot of em emerging technologies available to us. Classically, this was done on just axial two plane imaging and looking at some of the 3D reformats. But there's now another a number of companies in this space who are actually adopting machine learning and A I driven technologies to give us a better three dimensional appreciation of aneurysms. Looking for subtle change for patients that have multiple risk factors or aneurysms that are about, you know, 5 to 7 millimeters in size. A lot of times I'll consider doing a diagnostic angiogram to allow me to better characterize for any subtle irregularity of the aneurysm and also to help kind of serve as a baseline. Um for me to interpret further noninvasive imaging. Are there parts of the aneurysm that look more worrisome based off of their morphology? It also gives me a nice opportunity to once again have a um a follow up clinic visit with the patients to show them the pictures in high resolution and really develop a sound partnership with them with respect to our treatment options. There's been a lot of technological development with endovascular therapy and this is just a small animation depicting what we mean by endovascular therapy. So I describe it to my patients as taking a small needle and getting it gaining access into an artery in their wrist, usually the radial artery or at the top of their leg in the femoral artery, we're then able to go up with small hollow tubes that is kind of being depicted in this animation. And we're actually able to gain access within the aneurysm itself for most aneurysms and through even a a smaller catheter kind of demonstrated here, we're able to deploy detachable coils in order to stop the blood flow into the aneurysm. And over time, this promotes further clotting around these these aneurysm coils which then completes its exclusion from the circulation. I should note and one that we also have a number of different devices kind of highlighted over here that depending on the individual aneurysm morphologies, the sizes of the neck at the base of the dome of the aneurysm, we have a number of different devices that we can deploy such as stents, flow, diverting stents and even devices called intraocular devices that we could put in the aneurysm to accomplish this. Much of this is beyond the scope of the of this presentation. The important thing for primary care providers to know is that sometimes when we use these adjuvant devices, it requires the patients to be on dual antiplatelet medicines or some level of platelet inhibition. Um and that if patients develop problems with bleeding, especially posttreatment, that is something that you should um quickly involve the specialist just because the patients are on these medications to avoid avoid thrombo embolic complications from the device that's been deployed. So in many situations, we don't want to stop those in settings of minor bleeding. Obviously, if it's major life threatening bleeding, that's another situation. But that's something that should really be managed by the specialist um post treatment as far as open surgical clipping. Um This is just an animation to describe kind of what's involved in that. So I remove a small piece of the bone behind the the eye, I then open the covering around the brain and I don't actually work in the brain. I work through the potential spaces of the brain to gain surgical access to the aneurysm. We then visualize the aneurysm and dissect it nicely so that it's free and we put a titanium aneurysm clip um to close off the aneurysm so that it's no longer able to receive blood flow. An important note is that most aneurysm on, on all aneurysm clips. Now, um since the early two thousands are Mr compatible, they do not set off airplane metal detectors and so forth. And those are common questions that I get from my patient population as well as from outside providers. And the way that I decide and part of the rationale for seeking dual training to where we can be doing both endovascular therapy as well as open surgical clipping is to really be able to tailor the treatment strategy to each individual, some of the factors. And once again, this is an overly simplistic view of everything that goes into deciding how to best treat an aneurysm have to do with how wide the aneurysm's neck is. Um with wider necked aneurysm. Sometimes that favors an open surgical approach than a narrow necked aneurysm, especially in older patients where I worry about starting dual antiplatelet medications because of their fall risks for aneurysm location, aneurysms that are more closely located to the surface of the brain such as the middle cerebral artery are less efficaciously treated with endovascular devices. And we still lean on open surgery, deeper aneurysms. In contrast, that are more difficult to gain surgical access to are sometimes better treated and more safely treated with endovascular treatment. We also consider the patient's age younger patients, obviously um uh can handle the stresses of undergoing an extensive uh brain surgery better than younger patients. And the other thing that we also heavily consider is is the chances of the or the durability of the treatment result. Meaning how likely is it that we're gonna be able to treat this aneurysm and have the aneurysm cured for years to come. And with open surgery, those the the rates of retreatment are about 1%. Whereas those with endovascular devices hover around about 10% depending on the individual aneurysm as well as the device utilized. And you know, once again, our philosophy here at, at U CS F is to personalize treatment, leveraging our multidisciplinary approach. Um you know, really considering patients specific factors, age medical comorbidities and honestly also patient preference. Um Do patients respond well with the, the idea of knowing that their aneurysm may be retreated in the future or whether they really want a curative approach, even though it may be more aggressive upfront, as well as the aneurysm specific um characteristics as we, as I described on my, my previous um slide. Um I am proud I'm not the only provider who does this um at U CS F. Um Both interventional neuro radiology and neurosurgery in the cerebrovascular division have now been merged to make a comprehensive neuro endovascular team, which is now the largest in California. Beyond my clinical um expertise, I also direct a laboratory and these are just some of the young talented individuals that I'm fortunate to have in my laboratory that are really devoted on understanding the genetic risk factors and the molecular factors that cause aneurysms to form whether different molecular characteristics are associated with aneurysms that then go on to grow and hopefully one day getting closer to a medical therapy. So patients can avoid undergoing potentially risky interventions. And with that, I would like to conclude with some questions. I also just want to include my contact information. This is both my cell phone, email as well as a direct phone number um to my office. And you know, I look forward to establishing partnerships with all of you and I'm here to help. And I'm, um, you know, like I said, I'm happy to see any patient so that I could put their minds to ease even if it's not a patient that ultimately requires a treatment for an aneurysm. So thank you once again for all of your attention.
