Multiple sclerosis (MS) is a chronic disease of the central nervous system with 
not yet completely understood pathogenesis. The so called "chronic cerebrospinal 
venous insufficiency (CCSVI) theory" has recently emerged, supporting the 
concept of a cerebrospinal venous drainage impairment as the cause of MS. Since 
the first publication on this topic with a claimed 100% specificity and 
sensitivity of the condition for MS diagnosis, CCSVI theory has generated a 
scientific and mass media debate with a great hope for the miracle of a new 
possible endovascular treatment of MS ("liberation procedure"). We critically 
summarize the available evidence on CCSVI discussing inconsistent and incomplete 
replication of the original results by different groups, methodological 
limitations and potential therapeutic implications. We conclude that the 
available data are insufficient to establish conclusively a clear relationship 
between MS and CCSVI and do not support the role of CCSVI as the primary cause 
of MS. Until credible scientific evidence replicates the original results, any 
proposed invasive treatments of CCSVI should be discouraged.