The Difference Between An Aneurysm and An AVM

In attempting to “easily” explain the difference between an AVM and an aneurysm, if an aneurysm is a hand, would an AVM would be a finger on that hand?

aAnyone knowledgable on this? How do you explain the difference without linking to Wikipedia?

To me, an aneurysm is probably a consequence of an avm. The blood rushes through the avm at high pressure, which causes the artery to balloon out. So for an analogy, the avm is the hammer that hits you in the hand, and the aneurysm is the big bump that results.

I'll try a little different answer:

An AVM is a tangle of arteries and veins that join directly without going through capillaries. Therefore, high pressure blood flows from arteries to veins. The AVM can diminish blood flow to other areas, causing deficits.

An aneurysm is a weakness in a blood vessel wall that can allow the vessel to expand. This can put pressure on other areas. Of course, the risk is it can rupture, causing a bleed.

Think of blood vessels having multiple layers, sorta like radial car tires having plies. Blood vessels in an AVM are often malformed, missing some of the plies.

So I believe you can have an AVM separately, an aneurysm separately, or have both together. Just cuz you have one doesn't necessarily mean you will have the other.

In my wife's case, she started treatment for her AVM. After embo #2, a scan showed an aneurysm that hadn't been seen before. Maybe it occurred due to increased blood pressure after embo #2, or maybe it just wasn't seen before on scans, don't know.

If I were asked for a simple explanation, I would say:

AVM is a tangle of weaker arteries and veins without capillaries that has a risk of rupturing.
Aneurysm is the stretching of a vessel wall that runs the risk of bursting.

Hope this helps.
Ron, KS

To add a bit more information an Aneurysm is much more common than and AVM and in many cases more dangerous. My husband has had his angiograms/embolizations pushed back by a few hours due to emergency aneurysms coming into the hospital a few times.

Funny this topic is coming up, my husband had a meeting with a new doctor today (4 1/2 years since first discovery of the AVM) and the new doctor started talking about his aneurysm - which was complete news to us. Apparently there was an aneurysm, but it was taken care of during his first embo.

The simplest explanation I was given was, an AVM resembles a ‘clump’ of cooked spaghetti - malformed, weakened blood vessels all tangled up. (figures my Italian friend would describe it this way! lol)
Whereas an aneurysm is a weakened blood vessel that ‘balloons’ itself outward.
Both obviously very dangerous, yet for an ‘average’ person maybe wanting to know your condition without the details, it’s easily understood.

Ron--I really like your explanation! (I'm an AVM + annie gal--one of the aneurysms was found when they did my first Gamma Knife treatment. The 2nd annie was found during the craniotomy to clip the first one.)

THKS.
ron, ks

I think these images are very helpful differentiating an aneurysm. They are really quite frightful on actual scans and can get ENORMOUS before rupture. I like Ron's reference to the tire....I equate it to the "bubbles" that would sometimes form on the innertube tire on my bicycle when I was young. Hope it helps. -GK

325-BrainAneurysms300x261.jpg (15 KB)

This is the easiest for me to understand-thank you, all.



I was visualizing the aneurysm lone “noodle” - if I have that right- and pictured that snake that swallowed a mouse??? in “The Little Prince”. This example is especially helpful since we’re having pasta-nothing like infusing what you just ate or are going to eat with brain surgery lusciousness. Here’s hoping that everyone that I talk to already had a couple of alcohol-drinks.



Anyway, thanks for all of the analogies; I feel better prepared should anyone ask me at my parents’ 50th anniversary party…I’ll be the one in the hallway in a wheelchair with the tye-dye “Babe Magnet” sticker on it -you can’t miss me - struggling to sound “regular” (futile, I know).