Some United States hospitals have banned the surgical procedure outside clinical trials due to safety concerns until more evidence to support its use is available.In May 2012 the U.S. Food and Drug Administration issued a safety communication on CCSVI, stating that MS patients undergoing angioplasty and/or stenting to treat CCSVI risk serious injuries or death. Furthermore, it also noted that the benefits of these experimental procedures have not been proven and that studies exploring a link between MS and CCSVI are inconclusive. History
Venous pathology has been associated with MS for more than a century. Pathologist Georg Eduard Rindfleisch noted in 1863 that the inflammation-associated lesions were distributed around veins. Later, in 1935, Tracy Putnam was able to produce similar lesions in dogs blocking their veinsThe term "chronic cerebrospinal venous insufficiency" was coined in 2008 by Paolo Zamboni, who described it in patients with multiple sclerosis. According to Zamboni, CCSVI had a high sensitivity and specificity differentiating healthy individuals from those with multiple sclerosis. Zambonis results were criticized because his study was not blinded and his results needed to be verified by further studies. Zamboni had become interested in CCSVI in 1999 when his wife was diagnosed with MS.

Society and culture
Conflict of interest
Paolo Zamboni has patents related to the highly sensitive ultrasound diagnostic systems manufactured by Esaote which, he proposes, should be used to diagnose CCSVI. Moreover, Zambonis research center has also received support in the form of equipment and technical assistance from this manufacturer.
These include risk factors such as Epstein-Barr infection, parental ancestry, date of birth and geographic location. MS is also more common in women, while venous diseases are more common in men. Venous pathology is commonly associated with hypertension, infarcts, edema and transient ischemia, and occurs more often with age, however these conditions are hardly ever seen in MS and the disease seldom appears after age 50. Finally, an organ-specific immune response is not seen in any other kind of venous disease. Iron deposits
Iron deposition as a cause of MS received support when a relationship between venous pressure and iron depositions in MS patients was found in a neuroimaging study, and criticism as other researchers found normal ferritin levels in the cerebrospinal fluid of MS patients. Additionally iron deposition occurs in different neurological diseases such as Alzheimers disease or Parkinsons disease that are not associated with CCSVI. Evidence linking CCSVI and iron deposition is lacking, and dysregulation of iron metabolism in MS is more complex than simply iron accumulation in the brain tissue. Genetics
A small genetic study looked at fifteen MS patients who also had CCSVI. It found 234 specific copy number variations in the human leukocyte antigen focus. Of these, GRB2, HSPA1L and HSPA1A were found to be specifically connected to both MS and angiogenesis, TAF11 was connected to both MS and artery passage, and HLA-DQA2 was suggestive of having an implication for angiogenesis as it interacts with CD4.