All bonifide clinical trials include placebo arms
I think it is a bit more complicated as different countries, and probably even different universities, have different standards for different diseases. So in some cases there is not a placebo arm but there is a comparison group which may be on a generally accepted standard of care rather than a placebo per se.
If a study is framed as a trial regarding MS patients in the US, then the notion of a placebo arm, in my understanding, is really murky or even unlikely or not allowable. I am not exactly sure how a study framed as CCSVI and a "surgical" procedure fit in, but as Marie points out, there is a huge ethical consideration even if the standards of MS studies do not apply.