From Wikipedia, the free encyclopedia: en.wikipedia.org Chronic cerebro-spinal venous insufficiency (CCSVI) is a term used to describe compromised flow of blood in the veins draining the central nervous system. It has been hypothesized to play a role in the cause of multiple sclerosis (MS). This hypothesis was first put forth by Paolo Zamboni in 2008. An endovascular intervention for the syndrome has been attempted however further research is required to determine if the benefits outweigh the risks of the procedure.