CCSVI (Chronic cerebrospinal venous insufficiency)

Chronic cerebrospinal venous insufficiency (CCSVI) was a theory proposed by Professor Paolo Zamboni, a vascular surgeon. He suggested that abnormalities (including narrowing) of the veins draining blood from the brain and spinal cord may contribute to the nervous system damage in multiple sclerosis.

Numerous studies were carried out by different research groups but findings were contradictory. In 2017 a study led by Prof Zamboni concluded that the procedure to correct abnormalities in veins "cannot be recommended for treatment of patients with MS". This was confirmed by NICE in 2019.

The theory of CCSVI

CCSVI was proposed by Prof Zamboni following a study of 65 people with MS that found narrowing of the jugular vein in 91% and of the azygous vein (in the spine) in 86%. These abnormalities were not seen in a control group of people who didn't have MS.

The treatment for CCSVI was a surgical procedure known as percutaneous venoplasty or venous percutaneous transluminal angioplasty (PTA), which was sometimes referred to as the 'liberation therapy'. This procedure opened blocked veins by inflating a small balloon in the vein. In some instances the vein was kept open by inserting a stent - a small mesh tube.

When the National Institute for Health and Care Excellence (NICE) reviewed the evidence in 2019, they advised that the PTA procedure risked serious complications from damaging the veins, and provided no benefit in MS. 


A number of research studies investigated the association between venous insufficiency and MS. Generally CCSVI was more frequent among people with MS than amongst healthy controls, however, the prevalence of CCSVI in both people with MS and controls varied widely.

Studies showed that CCSVI was not a cause of MS.  Debate remained as to whether CCSVI was:

  • a cause of MS symptoms
  • arose as a result of MS
  • was coincidental and unrelated to MS.

In November 2017, results of a study led by Prof Zamboni reported that treatment for CCSVI produced no benefits for people with MS. The study involved 115 people with MS and CCSVI who received either PTA or a sham procedure. The results showed no difference in improved function between the groups. The researchers conclude that the procedure was "a safe but ineffective technique" and that "the procedure cannot be recommended for treatment of patients with MS; no further double-blinded clinical studies are needed.

In January 2019, NICE published its recommendation that CCSVI should not be used in MS as it has a risk of serious complications and provides no benefit.

Find out more

Zamboni P, et al.
Chronic cerebrospinal venous insufficiency in patients with multiple sclerosis.
Journal of Neurology, Neurosurgery and Psychiatry 2009;80:392-399.
Read article online (link is external)
Laupacis A, et al.
Association between chronic cerebrospinal insufficiency and multiple sclerosis: a meta-analysis.
Canadian Medical Association Journal 2011:183(16):e1203-e1212.
Read article online (link is external)
Torres C, et al.
Extracranial venous abnormalities: A true pathological finding in patients with multiple sclerosis or an anatomical variant?
European Radiology 2017 Jan;27(1):239-246.
Summary (link is external)
Zamboni P, et al.
Efficacy and safety of extracranial vein angioplasty in multiple sclerosis: a randomized clinical trial.
JAMA Neurology 2017 Nov 18 [Epub ahead of print].
Read article online (link is external)
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