Although it is debated whether chronic cerebro-spinal venous insufficiency 
(CCSVI) plays a role in multiple sclerosis (MS) development, many patients 
undergo endovascular treatment (ET) of CCSVI. A study is ongoing in Italy to 
evaluate the clinical outcome of ET. Severe adverse events (AEs) occurred in 
15/462 subjects at a variable interval after ET: jugular thrombosis in seven 
patients, tetraventricular hydrocephalus, stroke, paroxysmal atrial 
fibrillation, status epilepticus, aspiration pneumonia, hypertension with 
tachicardia, or bleeding of bedsore in the remaining seven cases. One patient 
died because of myocardial infarction 10 weeks after ET. The risk of severe AEs 
related to ET for CCSVI must be carefully considered.