["Chronic cerebrospinal venous insufficiency" in multiple sclerosis - is multiple sclerosis a disease of the cerebrospinal venous outflow system?].

Chronic impaired venous outflow from the central nervous system has recently been claimed to be associated with multiple sclerosis (MS) pathology. This resulted in the term chronic cerebrospinal venous insufficiency (CCSVI) in MS. The concept of CCSVI is based on sonography studies showing that impaired venous outflow leading to pathological reflux is almost exclusively present in MS patients but not in healthy controls. Based on these findings, a new pathophysiological concept has been introduced suggesting that chronic venous outflow obstruction and venous reflux in the CNS result in pathological iron depositions leading to inflammation and neurodegeneration. The theory of CCSVI in MS has rapidly generated tremendous interest in the media and among patients and the scientific community. In particular, the potential shift in treatment concepts possibly leading to an interventional treatment approach including balloon angioplasty and venous stent placement is currently being debated. However, results from recent studies involving several imaging modalities have raised substantial concerns regarding the CCSVI concept in MS. In this review article, we explain the concept of CCSVI in MS and discuss this hypothesis in the context of MS pathophysiology and imaging studies which have tried to reproduce or refute this theory. In addition, we draw some major conclusions focusing in particular on the crucial question as to whether interventional treatment options are expedient. In conclusion, the present conclusive data confuting the theory of CCSVI in MS should lead to reluctance with respect to the interventional treatment of possible venous anomalies in MS patients.