Authors: M. Arata, Z. Sternberg
Chronic cerebrospinal venous insufficiency (CCSVI) has been described as a condition resulting from impaired CNS venous drainage. Venous balloon angioplasty (BA) has been performed as a treatment for CCSVI. Autonomic nervous system (ANS) dysfunction has been proposed as mechanism underlying the occurrence of CCSVI. We hypothesize that the BA effect on clinical parameters is mediated by mechanical stimulation of perivascular autonomic fibers and is independent of vascular obstruction. The purpose of this study is to describe Trans-Vascular Autonomic Modulation (TVAM) in multiple sclerosis (MS) patients as a means of improving ANS dysfunction, comparing its safety and efficacy to the traditional BA.
Twenty-one MS patients who presented with symptoms of cardiovascular ANS dysfunction underwent TVAM. These patients were compared with twenty MS patients who presented with CSSVI, and who underwent traditional BA.
TVAM deviated from traditional BA in that target veins, bilateral internal jugular, azygos and left renal veins, were each dilated regardless of the presence of vascular abnormalities. This also included treatment of patients without evidence of abnormality in any of the target veins, eliminating the possibility of vascular effect. The improvement in cardiovascular ANS function was indicated by determining R-R interval variations during deep breathing (MCR, E/I ratio), valsalva maneuver (valsalva ratio), and postural changes (30:15 postural ratio).
The safety profile of the TVAM procedure was similar to that of the traditional BA with no adverse events occurring in either group. However, TVAM increased MCR, E/I ratio, and postural ratio more significantly than the traditional BA. Post-intervention, improvements were seen in the TVAM group relative to baseline for MCR (3.34±0.41 vs. 2.44±0.48, 36.4%, P = 0.08), E/I ratio (1.11±0.01 vs. 1.09±0.01, 1.8%, P = 0.3), valsalva ratio (1.95±0.09vs. 1.74±0.09, 12%, P = 0.10) and postural ratio (1.36±0.08 vs. 1.04±0.09, 30.7%, P = 0.027).
The postural ratio response in the TVAM group relative to baseline (1.36±0.08 vs. 1.04±0.09, 30.7%, P = 0.027) demonstrated the largest change relative to post-intervention postural ratio in the control group (1.36±0.08vs. 1.167±0.03, 16.5 %, P = 0.016).
TVAM mediated deposition of mechanical energy to central veins by balloon dilation, including anatomically normal veins, can improve indicators of ANS dysfunction. The observed safety and efficacy of TVAM is encouraging, paving the way for the treatment of ANS dysfunction in pathological states other than MS. Further studies should investigate the response to TVAM in larger cohort.