Vessels that feeds the AVM

Is there a way to tell if the vessels that feeds the AVM also feeds normal and important portions of the brain prior to Gamma Knife?

We were told that the vessels that feed an AVM do not feed healthy brain tissue.

Well, my answer is yes and no. Complicated, sorry.

No, as I’m not sure how they could test without doing an invasive test.

Yes, if you have an embolization (which you wouldn’t do routinely just to check for feeds prior to radiation), the process is after all the mapping is done, they feed the catheter through the groin into the brain. They follow the progress and location of the probe on like a real time scan (I’m not sure I have all the terms correct, sorry).

When they have the probe at the start of the feed where they hope to shut off (via embolization), they inflate a balloon at the probe which seals off that blood vessel. THEN, they do a neuro exam to see what if any deficits appear in the patient. If there are no deficits, or acceptable deficits, they deflate the balloon and inject the glue that seals off the vessel feeding the AVM. If the deficits are too great, meaning that blood is going from that vessel to a critical function, they can’t do the glue. A lot of the time spent in embos is finding a good spot to block the vessel.

I don’t recall Chari’s deficits (she’s not here to ask now), but I have spoken with other AVMers who when the balloon was inflated, lost all or part of their vision. One experienced color blindness, and consented to accept that to fix the AVM.

So my experience is that vessels feeding AVMs can feed good brain tissue. Otherwise, they would do embos a lot quicker.

Hope this helps.
ron, ks

This is the scary part with Gamma Knife is if they close off a good vein, you might be in trouble. I guess it’s a roll of the dice.

Ron, KS said:

Well, my answer is yes and no. Complicated, sorry.

No, as I’m not sure how they could test without doing an invasive test.

Yes, if you have an embolization (which you wouldn’t do routinely just to check for feeds prior to radiation), the process is after all the mapping is done, they feed the catheter through the groin into the brain. They follow the progress and location of the probe on like a real time scan (I’m not sure I have all the terms correct, sorry).

When they have the probe at the start of the feed where they hope to shut off (via embolization), they inflate a balloon at the probe which seals off that blood vessel. THEN, they do a neuro exam to see what if any deficits appear in the patient. If there are no deficits, or acceptable deficits, they deflate the balloon and inject the glue that seals off the vessel feeding the AVM. If the deficits are too great, meaning that blood is going from that vessel to a critical function, they can’t do the glue. A lot of the time spent in embos is finding a good spot to block the vessel.

I don’t recall Chari’s deficits (she’s not here to ask now), but I have spoken with other AVMers who when the balloon was inflated, lost all or part of their vision. One experienced color blindness, and consented to accept that to fix the AVM.

So my experience is that vessels feeding AVMs can feed good brain tissue. Otherwise, they would do embos a lot quicker.

Hope this helps.
ron, ks

Dawn,

I’m a long way from knowing about GK, but my wife did have two sessions of Proton Beam Radiation (PBR), which I think is like a cousin to GK. I’ve been following AVMs since the early 90s.

I have never heard anyone write to say that PBR/GK sealed off a vessel that caused a deficit. I’m not saying it doesn’t happen, but I’ve never heard of it.

When we did PBR (91 and 96, I think), we were told that the beams were shot to within ONE Millimeter of the target. And the best description I’ve heard on how it works: PBR is like depth charges. They travel through “good” tissue and “detonate” when they get to the target. By shooting from multiple angles, the target area is hit with multiple beams.

Although I don’t know how they do it, I can’t imagine they would blindly shoot radiation at an AVM without an understanding that it would not seal off good vessels, but maybe someone can enlighten us.

Take Care,
Ron

I would think if this was a risk then it would have been included in all the other possible risks that they told us before we proceeded with Gamma. Although there were alot of other things mentioned and we were given “worst case scenario” for sure, this was not mentioned at all.
I think you would need to specifically ask the neuroradiologist to be sure.