Evaluation of Clinical Trials for Multiple Sclerosis

The Saskatchewan government is planning to send over 80 of their residents ( with several million dollars) to the USA to participate in clinical trials evaluating the merits of the controversial "liberation treatment " for multiple sclerosis( MS). The rationale for this clinical project is based on what is commonly referred to as "correlational evidence" in this case MS with narrowing of the jugular veins which drain blood from the brain. With such a study the investigators hope to raise the clinical trial status from correlation to the gold standard of scientific evidence- i.e. cause and effect. I would refer the reader to my earlier Blog "The nature of Scientific Evidence April 20, 2011 " in which I state that correlation does not necessary mean causation or to use the words of Roy Walford "Correlation can be seductive , but its not actual proof ".
The local newspaper suggests this USA study presumably divides their MS patients into 2 groups- one group having the operation while the other presumbly only the sham operation. In my view there should be 4 groups those with and those without MS symptoms and those with and without narrowed vessels.
The criteria for a gold standard investigation is also dependant on controlling all variables but one- In this USA clinical study the status of the veins. Each patient is randomly assigned to either of the 2 groups, presumably without matching their genetically different properties. Without this knowledge and/or without control of these other variables is to use monozygous twins. In the "good old days " investigators would use inbred strains of mice or rats to eliminate the role of these variables in their study. Unfortunately there was also the question did such studies apply to humans ? - even when other primates were used like monkeys.So such earlier research had its shortcoming which prevented its inclusions in the category of scientific research.
Current investigators doing clinical trials to evaluate surgical procedures as in this case of MS and/or are evaluating drugs, for example cholesterol lowering drugs, do not have knowledge and/or control the status of this heterogenity of their patients, i.e. " those other variables" , are they justified in designating these research studies as supporting scientific evidence or proof?