I don't know if CV causes MS or MS causes CV, but if a proper test reveals that you have closed veins, then a proper Vascular surgeon, opening them up, can't be bad. You are bound to feel better if your veins are open with a proper flow from and to the heart and brain.
The procedure does NOT cure MS, but for many, it has improved their MS symptoms and their quality of life. Sounds like whay raising my endorphines with LDN, does for me!!!
I don't think the angioplasti is dangerous, but placing a stent in your vein, may be.

....So I would hold up on the stenting, untill it is perfected for veins. Even if that means doing angio more than once.