Venoplasty helps the pressure, and hypoxia but it does not address the iron in the tissues or the oxidation it could cause, which could definitely cause inflammation even after TPA. Macrophages try to remove iron, and iron laden macrophages are seen in MS in the inflammatory areas of the body.
A) Iron oxides get reduced and the oxygen crossed the BBB all alone, leaving the red blood cells with reduced iron. If there are a lot of venous blood cells crossing the barrier too, macrophages swallow them and some leave iron behind, in the tissues and elsewhere. This stops happening if the blood is going through fast enough (after venoplasty) that the red blood will not pass through the BBB (no adhesion molecules).
B) Iron can only oxidize, then contribute to other cells' oxidation if there is lots of free oxygen around. I thought getting rid of hypoxia was a good thing. Are you saying, if iron that shouldn't be there combines with some of the free oxygen that is normally delivered to tissues, it could starve them of free oxygen anyway? Is it now considered to be a free radical because it crossed the BBB as a cell and then became ionized fe, now chemically less stable, and easy to oxidize? That sounds like a reperfusion problem, doesn't it?