Reperfusion injury refers to tissue damage caused when blood supply returns to the tissue after a period of ischemia. The absence of oxygen and nutrients from blood during the ischemic period creates a condition in which the restoration of circulation results in inflammation and oxidative damage through the induction of oxidative stress rather than restoration of normal function.
Presumably in CCSVI, it is low-grade oxgyen deprivation, not total ischemia, although there would also seem to be trigger events where oxygen levels are stressed (perhaps childbirth, perhaps time spent at high altitudes).
I also think about my own procedure and the dramatic brightening of colors afterwards. The assumption is that the brightening was due to a restoration of normal brain oxygen levels.
So are we at risk of reperfusion injury, either in the normal course of our MS/CCSVI or immediately after the procedure, if the degree of oxygen deprivation was relatively severe?
We have known a few patients who have gotten worse immediately after what seemed to be a successful procedure in terms of no clotting and the blood flowing properly. We haven't had a good answer for that. It's only been a few cases.
The damage of reperfusion injury is due in part to the inflammatory response of damaged tissues. White blood cells, carried to the area by the newly returning blood, release a host of inflammatory factors such as interleukins as well as free radicals in response to tissue damage. The restored blood flow reintroduces oxygen within cells that damages cellular proteins, DNA, and the plasma membrane. Damage to the cell's membrane may in turn cause the release of more free radicals. Such reactive species may also act indirectly in redox signaling to turn on apoptosis. Leukocytes may also build up in small capillaries, obstructing them and leading to more ischemia.
Reperfusion injury may be the name for what we've been experiencing all along, when we talk about the white blood cells attacking. Steroids or DMDs would be effective against this. It can be an excessive reaction to the injury, so that as much or more damage is done by the white blood cells' attack as it was by the initial oxygen-deprivation injury.
Cheer has been saying all along that MS may be more comparable to a series of ischaemic events.
As for if reperfusion injury might occur (particularly in more easily inflamed brains?) as an immediate result of CCSVI treatment, I don't know. Hypothermia and hydrogen sulfide are the only things listed in wikipedia as protective against reperfusion injury. Presumably most of us have low grade chronic issues rather than acute, but we also have areas of CNS damage that might be particularly vulnerable to another insult.