Background: Chronic cerebrospinal venous insufficiency (CCSVI) in Multiple Sclerosis (MS)
Chronic cerebrospinal venous insufficiency (CCSVI) is a term coined by Dr. Paolo Zamboni of the University of Ferrara in Italy. CCSVI proposes that the veins in the head and neck are narrowed or blocked, and therefore unable to efficiently remove blood that circulates in the central nervous system. In his 2009 study, Dr. Zamboni demonstrated that CCSVI was present in all individuals with MS and suggested that the condition may contribute to worsening of MS. Furthermore, Dr. Zamboni proposed the treatment for CCSVI is angioplasty, also referred to as “liberation therapy”, or percutaneous transluminal angioplasty (PTA), a procedure that involves widening a vein by inflating a small balloon to improve draining of blood from the brain. This theory garnered a great deal of interest on the part of people with MS and their families and spurred many studies on CCSVI and MS.
Since 2009, research teams around the world have published conflicting results related to CCSVI and MS. To address these conflicting results, as well as questions about how these studies were designed and whether treatments to relieve CCSVI were safe, Dr. Zamboni initiated a large double-blind trial to investigate the safety and efficacy of PTA in people with MS. The results of this trial were recently published in JAMA Neurology.
The Study: Dr. Zamboni and his research team conducted a clinical trial to test CCSVI in MS
In a multicenter, double-blind, clinical trial, 115 individuals with relapsing-remitting MS (RRMS) were randomized in a ratio of 2:1 to either receive the PTA procedure or a mock surgical procedure for comparison. The two primary outcomes of this study were functional composite measure (mobility, balance, manual dexterity, residual urine volume, and visual acuity) and Magnetic Resonance Imaging (MRI) to measure new lesions, enlarged preexisting lesions, and gadolinium-enhancing lesions. The team also evaluated if there were any changes in Expanded Disability Status Scale (EDSS) or annualized relapse rates (ARR).
Results: Clinical trial of CCSVI shown to be ineffective in improving MS
One year after the procedure, the research team reported no change in the proportion of patients that improved on their functional composite measure compared to patients that received the mock surgical procedure. PTA also did not significantly reduce the number of new lesions at 0 to 12 months. EDSS scores and ARR were similar in both groups. Dr. Zamboni concluded that “venous PTA has proven to be a safe but largely ineffective technique; the treatment cannot be recommended in patients with MS.”
Comment:
The study performed by Dr. Zamboni’s research team is the largest clinical trial on PTA in people with RRMS to date and supports other research findings demonstrating no connection between CCSVI and MS, including current findings recently reported by Dr. Anthony Traboulsee from the University of British Columbia and his research team.
An unexpected finding from Dr. Zamboni’s study included a subgroup of individuals in the PTA group who had no new gadolinium-enhancing lesions. This may be the result of the effect of PTA on the blood-brain barrier (BBB). Despite these findings, the authors stated that no further clinical trials assessing PTA as treatment for MS are necessary, yet future studies could potentially explore the impact of PTA on the BBB.
Source:
Zamboni P et al. (2017) Efficacy and Safety of Extracranial Vein Angioplasty in Multiple Sclerosis: A Randomized Clinical Trial. JAMA Neurol. [Epub ahead of print].