A Pathologic Evaluation of Chronic Cerebrospinal Venous Insufficiency (CCSVI) (P05.125)

Abstract

Objective: To assess for venous abnormalities possibly related to CCSVI in MS and control cadavers. Background Chronic cerebrospinal venous insufficiency is a new theory of MS pathogenesis involving alterations in cerebral venous outflow. There has been little pathologic study of venous structures related to CCSVI. Design/Methods: We harvested bilateral internal jugular (IJV), subclavian, brachiocephalic, and azygos (AZY) veins from 7 deceased MS patients and 6 non-MS controls. Veins were flushed, injected with silicone, dissected en bloc, and fixed. All valves and structural abnormalities were characterized and photographed using a stereomicroscope. Results: Valvular and other intraluminal abnormalities with potential hemodynamic consequences were identified in 5 of 7 MS patients (7 abnormalities) and in 1 of 6 controls (1 abnormality). These abnormalities included circumferential membranous structures (1 MS; 1 control), longitudinally-oriented membranous structures (3 MS), single valve flap replacing IJV valve (2 MS), and enlarged and malpositioned valve leaflets (1 MS). Significant stenosis was seen in 2 MS and 1 control. Additionally, several minor anatomic variations without expected hemodynamic consequences were observed similarly in both MS and controls. These included valves with 3 leaflets, the presence of AZY valves, additional (duplicate) normal-appearing IJV valves, and small accessory valve leaflets. Histologic evaluation is underway and will be reported along with additional cases. Conclusions: Post mortem examination of the IJV and AZY veins in MS and non-MS controls demonstrated a variety of structural abnormalities as well as anatomic variations. Vein wall stenosis occurred at similar frequency in both groups. However, the frequency of intraluminal abnormalities with possible hemodynamic consequences appeared higher in MS patients compared to healthy controls, although the current sample size is limited. These results suggest that MRV studies evaluating vein wall stenoses may be less effective than ultrasound in identifying venous abnormalities in CCSVI. In addition, CCSVI ultrasound studies should include focused evaluation of intraluminal abnormalities. Supported by: RC 1004-A-5 from the National MS Society. Disclosure: Dr. Diaconu has nothing to disclose. Dr. Staugaitis has nothing to disclose. Dr. McBride has nothing to disclose. Dr. Schwanger has nothing to disclose. Dr. Rae-Grant has received personal compensation for activities with Novartis, Biogen Idec and Teva Neurosciences as a speaker. Dr. Fox has received personal compensation for activities with Avanir, Biogen Idec, EMD Serono, and Novartis. Dr. Fox has received research support from Biogen Idec and Genentech, Inc.