Incidentally discovered aneurysms in the brain-what to do about them?
Nitin K Sethi, MD
Assistant Professor of Neurology
New York-Presbyterian Hospital
Weill Cornell Medical Center
New York, NY 10065
Recently I saw a patient in my office. She had undergone a MRI scan for headache. The MRI scan revealed a 4 mm aneurysm in the left middle cerebral artery with a 2 mm neck. I reassured her that the aneurysm was not the cause of her headache and that she more than likely had migraine headaches when she asked me the million dollar question which I had been expecting all along.
Dr. Sethi, but what to do about the aneurysm? Can it rupture? Do I need surgery to take care of it she asked me? I answered her questions according to the best scientific evidence I had at my disposal. That patient visit though got me thinking about how many patients face the same dilemma. That is the purpose of this post. When aneurysms are discovered incidentally in the brain, what needs to be done?
In keeping with my style of writing, I shall keep this simple. Simply put when an aneurysm is discovered in the brain, there are 2 avenues open to us.
Avenue 1. DO NOTHING (otherwise called the WAIT AND WATCH policy). The aneurysm may never rupture in the patient’s lifetime so why touch it. The wait and watch policy works best for aneurysms which are small in size (less that 5 mm in size, some books say aneurysms less that 7 mm in size may be safety observed). Small sized aneurysms in hard to reach areas of the brain can be justifiably observed. What do I mean by hard to reach areas of the brain? Let me explain with the aid of an example. Let us assume Kim our fictitious patient has a 3 mm aneurysm in the cavernous portion of the left internal carotid artery. This is the portion of the internal carotid artery that traverses the cavernous sinus. Now this area is difficult to reach “safely” by the neurosurgeon. The risks of surgery are tangible and may outweigh the potential benefits (remember as the aneurysm is small in size the risk of rupture is low). Better to wait and watch rather than go about chasing this aneurysm.
I said WAIT AND WATCH not WAIT AND FORGET. Meaning the patient should be advised to remain in follow up. The aneurysm should be followed by serial MRI scans done at intervals varying from 6 months to 1 year. Initially the follow up is more frequent, once we have documented that the aneurysm is not increasing in size, the scans can be repeated less frequently. If the aneurysm starts increasing in size then a more “active” course can be pursued. If the patient is hypertensive, good blood pressure control should be the goal as risk of aneurysm growth and rupture increases if blood pressure remains elevated.
Avenue 2. PURSUE AN ACTIVE STRATERGY. Simply put it means “taking care” of the aneurysm surgically either via open craniotomy or via an endovascular approach. Let me explain this. Let us assume Kim has a 10 mm sized aneurysm is the right middle cerebral artery territory. We can approach this aneurysm in 2 ways. First is via an open craniotomy, meaning that open up the skull (we call this a craniotomy), visualize the aneurysm and then secure it with a clip or a band. Once the aneurysm is clipped it cannot rupture as it is excluded from the circulation. PROBLEM SOLVED!!!
Second approach is via an endovascular route. No craniotomy is required. The endovascular surgeon or the interventional neuroradiologist threads a catheter via the femoral artery in the groin and reaches the aneurysm in the brain. Once there he coils it (coils of platinum coated with a thrombogenic material are deployed inside the aneurysm). Over time the aneurysm clots and seals itself from the circulation. PROBLEM SOLVED!!!
Broadly speaking endovascular coiling is superior to open craniotomy (at least in some respects). As no craniotomy is required hospital stay is shorter and post-operative recovery quicker. The endovascular surgeon can reach areas where the neurosurgeon may fear to tread. Certain aneurysm though are not amenable to coiling (example those with a broad neck as the coils fall out). Also once an aneurysm is coiled it takes time before it gets completely thrombosed, surgery on the other hand takes care of the problem then and there.
Filed under: Uncategorized | 9 Comments
Tags: aneurysm, clipping, coiling, craniotomy, endovascular surgery, incidental aneurysm, intracranial hemorrhage
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There is so much interesting information here, Dr. Sethi, I believe I could occupy your good graces with too many questions.
I can’t believe the arterial walls are that tough to allow something to enter the femoral artery and be threaded into the brain without being punctured. I assume that once in the brain you may also enter the smaller veins, even more delicate. It would seem to me that the tip of whatever is being threaded would catch on something or scrape a wall too hard. It’s amazing that such miniature work can be done deep inside us. The coming Nanotechnology should keep you guys from getting bored.
Of the two though, I’d prefer that approach rather than entering my skull. Perhaps I’ve watched too many horror movies, I don’t know.
Hope you are well, Doctor.
Dear Paul,
as always thank you for writing in. The guide wires which are threaded into the arteries are flexible. The procedure is quite safe in experienced hands. That said and done like every other procedure, endovascular procedures too have their risks of morbidity and mortality. A lot depends upon the skill and experience of the endovascular surgeon.
I too would prefer the endovascular route. The procedure is essentially “sterile”. No blood or gory. But I have to admit it is something when you see the skull sawed open in the OR or burr holes drilled into it.
Hmmm maybe I should stop seeing horror movies finally.
Hope you and your family are well. Enjoy your summer and stay in touch.
Personal Regards,
Nitin Sethi, MD
Hi. I read youir blog and am now very frightened. I was just diagnosed with a 2.5 x 2.5 x 3.5mm saccular aneurysm involving the mid cavernous left internal carotid artery oriented inferolatterally.It is in an extradural location. So,this cant be removed?
Dear Hanna,
please do not be frightened. Aneurysms which are in the cavernous sinsus are at times hard to approach neurosurgically. You should follow with your doctor. He/she shall be the best person to advice you further.
Personal Regards,
Nitin Sethi, MD
Dr. Sethi-
I can’t believe I came across your post regarding the major question small aneurysm patients face: what do I do about it? I had an MRA last week that my primary care doc says shows an incidental finding of a very small 3mm aneurysm in the anterior communicating artery. He was very low key about this finding. I’m 36 yrs old. I have no symptoms, have managed blood pressure, absolutely no family history of aneurysm or stroke related deaths. But I’m going to see a neurosurgeon for a consult. I am scared to death of open brain surgery. I’ve got 2 kids and a third on the way in October and I’ve ready horror stories of people being off work for months recovering from craniotomy surgery like this. Do you think a watch and wait approach is possible given the small size of mine? Is it possible for these to remain unchanged and not grow or is inevitable that they will grow making treatment inevitable at some point? My PCP doesn’t seem to be able to answer that fundamental question. Thanks,
-Jason in Cincinnati.
Dear Jason,
thank you for writing in. Anterior communicating artery (ACoM) aneurysms can be tricky with respect to prognostication about the risk of rupture at a future date. I shall not offer a opinion here (as I have neither seen you nor reviewed your MRI/MRA myself). Follow up with the neurosurgeon. Remember you can always seek a second opinion and then make an informed decision.
There is no reason to restrict your normal activities. I would do what you are already doing-keep your blood pressure well under control and avoid contact sports.
Personal Regards,
Nitin Sethi, MD
One last hypothetical question. If you give a patient the wait and see approach (like the fictitious patient “Kim” above with the 3 mm aneurysm, do you significantly limit their activities? If they were active people (I run 3 days a week and play non-contact sports like basketball and soccer), are they permitted to live their normal lives while watching or must they walk on egg shells and quit all activities that raise their heart rate?
Thanks so much for your response Doctor. I realize you can’t give medical advice without reviewing tests, exams, etc. I do have a general question regarding small acom aneurysms like mine. Is endovascular coiling an option for these? Do small anuerysms like this sometimes not grow/increase in size? Its the one thing I don’t seem to be able to get a straight answer on: is the idea of watching and waiting because some may never grow over one’s life and remain small and low risk, or do they always grow over time/years? Thanks,
Dear Jason,
like I said in my post, small aneurysms at times can be watched. Some may never grow in size and hence no active intervention is warranted. We usually follow these aneurysms with serial MRI/ MRA scans. Only a doctor who has looked at your scans shall be able to advise further. Small anterior communicating artery aneurysms can be endovascularly coiled. Again this can only be determined after looking at your scans. Sometimes a formal angiogram is done prior to any intervention (surgical versus endovascular coiling vs watchful waiting).
Personal Regards,
Nitin Sethi, MD