If people with CCSVI are at greater risk of clots, maybe that's why ballooning can be destructive for some. Certainly it would make closer after-care and monitoring crucial.
It's an unanswered question if pwCCSVI are at greater risk of clots but it's been suggested before. Another idea is if you have weak flow in the upper portion of the jugular, that puts you at greater risk of clots when the lower portion of the jugular is ballooned, because it has less flow coming down the pipes.
The fact that we are using balloons can mislead. The fact that these are rubber does not mean they are soft. A thick-walled, very small balloon filled with liquid is very hard.
Some docs are using high-pressure balloons as well.
The arteries or veins are non-existent to a dilating balloon. Of course, doctors know that, and are very careful. But being as hard as they are, balloons are certainly capable of damaging the inside of a vessel.
This, I think, is why sizing is so critical. An undersized balloon will not damage a blood vessel that is larger than the balloon itself. An oversized balloon will. As always IVUS is a good way to get the three-dimensional exact size of the vein, as opposed to two-dimensional measurements taken in the traditional flouroscopy.
They are being used to intentionally disrupt malformed valves. Damage results in clots if you don't control them.
So we can come full-circle if the clots result in new membranous obstructions. Is this more likely in someone who has them already?
Thinking about it more, in CCSVI we're not seeing the clots result in new membraneous obstructions, we're seeing full occlusions and death of that portion of the vein, aren't we? Maybe a membraneous obstruction would be a more likely outcome in the azygous with its more constant flow.