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Stent Questions

Posted: Wed Aug 19, 2009 5:11 am
by CureOrBust
A couple of stent question to quell my curiosity.
1. What did Zamboni mean by the following.
However, no attempt at a stenting procedure was made in the absence of a dedicated device capable of preventing migration. This device would fit the particular morphology of the intemal jugular vein, similar to a upside down milk bottle, and, finally avoid protrusion into the brachiocephalic trunk.
2. Where in relation to the stents Dr Dake is inserting, does the IJV valve reside?

Hmmmm... not sure how to word the next two
3. How flexible are the stents as used by Dr Dake,
4. and how resilient to deformity are they?

An example would probably be best. for (3) If I had a stent in my hand, could I bend it into a curve / semi-circle like I could with a spring?

And for (4) if the stent was on a flat hard surface, how flat could it be depressed, before it would not return to the original shape? Would a thin bicycle wheel crossing it cause it any deformity?

The image of one in place (thank-you to alex :) ) made it appear as if it was designed to be very flexible, but, I haven't ever had the pleasure of "playing" with one.

Posted: Wed Aug 19, 2009 8:11 am
by mrhodes40
I did not run a bicycle tire over a stent so can't say what would happen there Cure :wink:

But I worried I would crunch my head down too hard and then end up with a crimp, like a straw that got bent, in my stent. I told my GP this and she laughed and said no they don't crimp like that they are designed to do what they do and to stay open......

Cheer held one maybe she will say what it felt like

Every location is different I have a carotid stent on the left ...this is a stent designed to be in this mobile location as the jug and carotid are in the same sheath. My other side was trickier, they started with a carotid stent then took it out as it was not the right size and did not work for me so I ended up with a hepatic stent. This stent is large and made for venous application and it fit the location and my anatomy better than the first one.

I heard that a person had a jugular that was 30mm! For comparison my big stent is 12, the small one is 8. They would need something specific for them.

One of the things I like about this is that it does recognize the individuality of each of us. There is no formula that is applied to all of us like we are the same person juhst because we all have the word "MS" applied to us.

What I am saying here is that this is individual. Your stents would be what worked for you, not some textbook thing.

BTW the brachiocephalic is on the bottom end of the jug so that milk jug stent is for a specific location to accomodate the anatomy in that location. Apparently this is an area for stent development.

and the IJV is not an issue for some of us our stenosis is higher up, mine is very high so the valves are not impacted.

here is a IJV paper on valves. Note that they recognize that this periodic retrograde flow is damaging to the brain and its function.

http://www.jultrasoundmed.org/cgi/content/full/21/7/747

I do not know what kind of stent Dr Dake might use if it was your valve that was stenosed. That is a good question for him.

Posted: Wed Aug 19, 2009 9:29 am
by zap
Something I have been wondering about is how the stents - and the natural veins on either side - handle the collapsing and opening up of the jugulars.

As you probably know, the jugular veins collapse when we are upright, and open up again when we lie down.

http://jp.physoc.org/content/560/1/317.full.pdf

I assume the stents do not collapse along with the natural vein - and I wonder if the wear and tear on the venous walls at the boundaries of the stent - caused by the veins collapsing flat right up to the stent edges, over and over - could create problems.

Posted: Wed Aug 19, 2009 11:03 am
by mrhodes40
Here's a picture of a stent in a guy's hand being bent sharply Cure

http://www.virchicago.com/carotid-artery-blockage.htm

here's an image search that resulted in many pictures of stents in carotid arteries and also pictures of stents in people's hands. This page is interesting you can look at and read a ton of things associated with this.

My impression overall after looking at these many images is that stents in carotid arteries is so common and well understood that it is done in all types of situations, some of these arteries are ballooned way out and in others they are pinched off almost totally, sometimes there is another artery nearby, or multiple structures. Sometimes they place a bunch of stents and they make curved stents and all kinds of things. I can see how someone like Dr Dake who does these carotid things all the time looks at something like my neck and says "I can fix that....., I don't know what will happen with the MS but we can sure restore blood flow"

In case it does not come up I put "carotid stent image" into the bing
search engine

Zap I assume as you did the jug is closing per usual in the rest of its length, but I did not ask Dr D about the "wear and tear" on the ends of the stent issue.

It seems possible there could be wear and tear, but then again from the carotid angle, the arteries pulse actively and vigorously which is why we can feel it. Stents are common in arteries and they are pulsing 60 times a minute. The several times a day a persons jugs alter their diameter seems insignificant compared to that, so it seems that if that were to be a problem it would already be known and understood from the artery side of things

Also veins are passive, so the vein collapsing is a relative event and not forced by muscles or anything, so my guess is that it just accommodates passively. After all, a vein can distend to great increases in size in a person with vericosities. just MHO

Posted: Wed Aug 19, 2009 11:19 am
by zap
Yeah, I guess really only time will tell. I like the arterial pulsing analogy although I dont know if these are apples and oranges, since the walls are so different and unlike pulsings*, the veins collapse utterly flat.

Thanks!

* actually I have no idea if that assumption is true

Posted: Wed Aug 19, 2009 11:41 am
by mrhodes40
Yeah I agree this is new and only time will tell the final truth of it all. Medicine learns all the time and that is the truth!

Posted: Wed Aug 19, 2009 6:28 pm
by CureOrBust
that's exactly what I was talking about in case 3
Image

Now I need to find an image of a bike rolling over one. :?