Neurosurgeon Luis Savastano, MD, PhD, discusses middle meningeal artery embolization, a cutting-edge, outpatient procedure for subdural hematoma. Advantages over the traditional surgery include minimal risk, little or no need for sedation, and prevention of recurrence. Learn which patients are candidates.
Hello, I'm Luis Sabastano, and I am a neurosurgeon at the University of California, San Francisco. We're going to be talking today about embolization of the middle meningeal artery for the treatment of subdural hematomas. Uh, this is a new but very common intervention that we're doing within the cerebrovascular neurosurgery group and neuroendovascular surgery. To start, chronic subdural hematomas are very common in elderly patients. Basically, the subdural hematomas are expanding blood collections over the brain surface. That are as common as 20 cases every 100,000 people when you're 65 years old or older. In the US every year there are about 60,000 cases, and of those, one third are going to need surgery to drain this hematomas. Is probably becoming the most common neurosurgical intervention that we're doing, and it's becoming more and more prevalent for two main reasons. Number 1, we have an aging population. In the process, the brain, the brain shrinks and the, the fluid starts to accumulate in the surface, especially when you are taking blood thinners or antiplatelet agents such as aspirin. What you are seeing on the right of the screen is the common example of chronic subdural hematoma, which is this fluid collection. Which is pushing on the brain and builds up between the brain and the skull. Classically, we have been draining these collections of fluid or blood by doing borehole surgery, which is a surgical intervention where we open one or more holes in the skull and then we irrigate the fluid collection out. This is how it looks in the OR, which is basically two boreholes being done, and then you can see how at the end of the intervention we are putting a drain. Within this subdural space which is going to remain in the head for 2 to 3 days while the patient is in the intensive care unit to allow more of this fluid collection to drain out and after surgery this is a common appearance of basically the burr holes. This intervention, as I mentioned, is extremely common but has one major problem, which is that 1 out of 4 patients, they're going to come back to the hospital within 30 days of admission. Um, with a recurrent subdural hematoma. That means that every 4 surgeries that we do, 1 patient, or 25%, is going to come back to the hospital and require more surgeries. And the, the reason for that is that there is an artery called middle meningeal artery that goes to the dura. And you can see here a contrast injection within the artery. You can see how the artery has multiple branches which are spanning the whole cranial circumference. And then what happens is in elderly patients when they start having small amount of blood, the blood creates inflammation. The inflammation creates more blood vessels, and those blood vessels are very delicate and they are leaky. So what you can see here are a lot of membranes with very leaky blood vessels which over time they allow the hematoma to grow, and that is the main reason for the recurrent subdural hematoma after surgery. So the, the problem here is that when we have this situation, we have more bleeding than reabsorption from these leaky membranes, and that drives subdural hematoma formation. So when we're doing an embolization of the artery, which meaning occluding the artery, we are preventing further bleeding and the reabsorption keeps happening. So over time the subdural hematoma goes away. So this intervention is called middle meningeal artery embolization or MMA embolization, and these are the basically the, the, the steps that we do during this intervention. We start by injecting a contrast into a tiny catheter that we have navigated from the wrist or from the groin all the way into the middle meningeal artery, and then you can see that all the arteries are open. Then from the inside of the artery we deliver different uh embolization agents which can be particles or can be liquid uh substances that they are going to flow downstream and they're going to occlude all these branches. So what you are seeing here is after our embolization how we have trimmed or occluded all these arteries going to the dura. This intervention is usually outpatient. It's minimally invasive, so we need no sedation or minimal sedation, and as I mentioned, it's exclusively endovascular, meaning that we're putting our catheters in the radial or the femoral artery or the wrist or the groin, and through that we can navigate following the arteries all the way to the skull. The goal is to permanently occlude the artery, the middle meningeal artery, to prevent further bleeding. And as I mentioned, is a relatively a safe intervention with the risk of 1% or less. And being minimally invasive, there is no really downtime for the patients. They don't have to recover from an open surgery like the borehole surgery. There are 3 main indications to embolize the middle meningial artery. The first one is in patients that presents with the subdural hematoma. That have not had any other therapy. These subdural hematomas are usually larger than 1 centimeter. They have acute blood components. They are growing or they're high risk of expansion. Patients are minimally symptomatic, so we can embolize the artery and the patient will have enough time in the next few weeks to reabsorb the fluid collection without the need of surgery. The second indication is when we have patients that are symptomatic from the subdural, meaning that they need to have the clot evacuated with surgery, but we are concerned that they are at high risk of a recurrent subdural hematoma, for example, because they have brain atrophy or because they have liver or or renal failure or because they have to go back on the blood thinner medication soon. So in those cases we can do surgery and the MMA embolization at the same time, which at UCSF we do by the same interventionist in the same room under one setting. And finally, one of the most common indications for MMA embolization is in patients that have had surgery from a previous subdural and after a few weeks or a few months they return to our clinic with a recurrent subdural hematoma and at that point rather than doing a second surgery we are embolizing the middle meningeal artery. Just to give you two case examples, this is a case example of an upfront embolization which you can see that this was a 70 year old lady that had very low platelets in the setting of chemotherapy that presents with progressive headaches and difficulties walking, but she was still very functional. Uh, you can see in the head CT that there is a large subdural hematoma pushing on the brain. That patient was medically ill but functionally she was doing well from the subdural, so we decided just to do the MMA embolization. You can see that a few months after the fluid collection completely resolves, and the reason is because it stops bleeding and then eventually the bruise goes away as anywhere else in the body would do. This is another example when we have an elderly patient that was taking anticoagulation and you can see that after falling from a ladder he had a very large subdural hematoma. This patient had surgery to evacuate this clot, but one month later, we can see that there is now a chronic subdural that slowly grows over time, and at that point we have not initiated anticoagulation yet. So that is a a good patient that would benefit from the MMA embolization which was done in this case and you can see that after a few months the fluid collection has been completely reabsorbed despite being on warfarin. So in summary, MMA embolization is a highly effective intervention that can decrease more than 10 times the likelihood of a recurrent subdural hematoma after drainage. Meaning decrease 10 times the likelihood of needing a second operation. The intervention can be a standalone therapy for selected patients which obviates the risk and the discomfort from open surgery and in addition, by doing the MMA embolization, we can restart sooner the antiplatelets or anticoagulation medication that the patient needs. MMA embolization it's purely an endovascular intervention, minimally invasive, that can be done as an outpatient procedure with minimal downtime. At the bottom of the screen you see our contact information, so please call, fax or email with any questions anytime about any patient that you would like to discuss. Thank you, have a good day.
