Objective duplex ultrasound evaluation of the extracranial circulation in multiple sclerosis patients undergoing venoplasty of internal jugular vein stenoses: a pilot study.

OBJECTIVE: Chronic cerebrospinal venous insufficiency (CCSVI) is a condition associated with multiple sclerosis (MS) and manifested by stenoses in the extracranial venous circulation. There is a need for an objective non-invasive assessment of CCSVI that is able to accurately identify the location of stenoses and quantify physiological changes in blood flows following treatment. METHOD: A duplex ultrasound method, extracranial duplex ultrasound (ECDU), is described where the internal jugular veins (IJVs) and vertebral veins (VVs) were examined in the supine and sitting position before and after venoplasty in eight patients with clinically diagnosed MS. High-resolution B-mode imaging was used to detect obvious stenoses, intra-luminal membranes, valve abnormalities and vein wall thickening. ECDU was then used to assess blood flow including reflux. To assess obstruction, venous blood volume flows (BVFs) were taken bilaterally from the proximal (J1), mid (J2) and distal (J3) segments of the IJVs and the mid cervical VVs. To assess cerebral perfusion, bilateral BVF measurements were taken, in the supine position only, from the proximal internal carotid arteries (ICA) and mid cervical vertebral arteries (VA). The global arterial cerebral blood flow (GACBF) was then calculated as the sum of the ICA and VA measurements. RESULTS: Pre-venography ECDU detected IJV stenoses or obstruction in all patients. Venography findings were consistent with those of the pre-treatment ECDU with the exception of the detection of bilateral IJV stenoses in two patients diagnosed with unilateral IJV stenosis by ECDU. A significant improvement in GACBF was evident following venoplasty (p < 0.05). A trend to improvement in the post-treatment BVFs of both the IJVs and the mid cervical VVs was also observed. This improvement was most marked in the left VVs (p = 0.052) and the J2 segment of right IJVs (p < 0.05). CONCLUSION: The ECDU examination described provides a reliable objective assessment of IJV and VV stenoses and, with the use of BVFs, can quantify the degree of obstruction. These results support the use of ECDU as a non-invasive post-operative assessment of the success of venoplasty. The ability of ECDU to measure GACBF provides an additional parameter to monitor vascular pathophysiology in MS patients. The current findings support the view that the early symptomatic benefits observed after venoplasty for stenoses in the extracranial venous circulation may be the result of increased cerebral perfusion.