"MS patients who claim to have benefited from treatment for CCSVI are only experiencing a placebo effect."
While this assertion appears unlikely, a full answer cannot be known until further research is completed.
To begin with, differentiating placebo effects from the effects of any intervention (pharmaceutical, surgical, etc) is complex. The placebo effect has, in some circumstances, proven to be resilient, long-lasting, and powerful. It has even been attributed to shrinking cancer tumors12. Differentiating placebo effects from treatment effects is typically done via a placebo-controlled double-blind experiment (an experiment where a mix of real/sham treatments are provided and where neither researcher nor patient know whether they are prescribing/receiving the actual treatment or the sham). With many pharmaceuticals, this type of experiment is relatively straightforward because a sham or sugar pill treatment is easy to dispense. However, providing a sham CCSVI endovascular procedure is far more complex, and extremely expensive. Primarily due to the costs, ethical considerations, and complexity, blinded, sham-controlled trials of CCSVI treatments have not yet been conducted (although at least one is in the planning/funding stage). Therefore, one cannot definitely differentiate the role of placebo versus the role of treatment based on currently available CCSVI treatment research.
At present, the only published study on CCSVI Treatment outcomes is Dr. Zamboni’s 2009 “Open Label” study. By definition, an open label study does not use blinding or controls. Critically, this does not mean that results of open label studies are “flawed” or “unscientific”; it simply means they are limited. The purpose of an open label study is to test safety issues, to evaluate results for encouraging trends, and to use this data to help design future research projects. Dr. Zamboni’s open label study on CCSVI Treatment addressed exactly these issues. (Note that Dr. Zamboni’s studies confirming CCSVI and linking CCSVI to MS used a controlled/blinded format).
Following an open label study, the aim of subsequent research will be to more extensively investigate cause, effect, and treatment efficacy by controlling for a wider range of variables. These studies will be completed when more funding is available. Researchers from around the world have submitted proposals for CCSVI research projects to the Italian, Canadian, and U.S. MS societies. Unfortunately, due to the high costs of placebo controlled surgical studies, the monies made available to-date by the U.S. and Canadian societies will allow for only limited research.
Despite the lack of placebo controlled experiments, there is some interesting evidence that at least some of the outcomes seen in Dr. Zamboni’s Open Label study were not the result of placebo alone. For example, some of Dr. Zamboni’s patients have been symptom and/or relapse free for nearly two years. While the placebo effect may endure for years, this is uncommon. If patients who have received CCSVI treatment continue to show positive results over the long-term, then the assertion that these results are caused by placebo alone will continue to lose credibility.
Perhaps the most interesting indication that placebo alone does not account for Dr. Zamboni’s Open Label findings is that, for RRMS patients receiving treatment, only those who experienced restenosis suffered MS relapses. All patients whose treatment remained patent were relapse free throughout the 18 month trial. This result suggests that the placebo effect was not responsible for positive outcomes: If placebo was responsible for positive outcomes, there would be no difference in outcomes for those who restenosed versus those who did not. Thus, because positive outcomes are strongly associated with patency, and not merely with the procedure itself, placebo appears to be secondary to effects of the treatment. Nonetheless, further research is needed before any firm conclusions can be reached.