Tuesday, August 24, 2010


I have come across a bit of information on some venous stents that I wanted to forward to everyone. While not a solid solution yet for CCSVI it's obvious things are moving tin the right direction.

WALLSTENT® Venous Endoprosthesis with Unistep™ Plus Delivery System
What is it? The WALLSTENT Venous Endoprosthesis (WALLSTENT) is an implantable stent, an expandable, tube-like scaffold that is mounted on a flexible wire called the Unistep™ Plus Delivery Catheter. It is used in hemodialysis patients who have a blockage in a major vein near the heart called a central vein. This blockage could lead to failure of the graft that allows the patient to be connected to the dialysis equipment. The WALLSTENT is threaded into the narrowed portion of the vein, where it expands and holds open the vein's inner walls. The larger opening allows an increased flow.
From Boston Scientific on this stent: 
Wallstent® Venous Endoprosthesis with Unistep™ Plus Delivery System 
The Wallstent Venous Endoprosthesis is indicated for improving central venous luminal diameter following unsuccessful angioplasty in patients on chronic hemodialysis with stenosis of the venous outflow tract. Unsuccessful angioplasty is defined as residual stenosis ≥ 30& for a vein ≤ 10mm in diameter or ≥ 50& for a vein > 10 mm in diameter, a tear which interrupts the integrity of the intima or lumen, abrupt lesion site occlusion, or refractory spasm. The vessels that can be treated with the Wallstent Venous Endoprosthesis are the innominate and subclavian veins, ranging from 8.0 mm to 15 mm in diameter. 

This particular stent has been in use for years. This recent FDA approval was only for two very specific veins at the subclavian level. 

Wallstents are made of stainless steel, meaning that any patient getting them would not be able to undergo MRI studies after implantation, not a good thing for people with CNS problems. Article: http://radiology.rsna.org/content/204/2/343.short

Additional information: Summary of Safety and Effectiveness and labeling are available at: http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cftopic/pma/pma.cfm?num=p980033
Stentys self-expanding stent Video: http://www.youtube.com/watch?v=D8bx99ZA-eU
Interventional Radiologists have recently reported to patients that there are even newer stents with even greater radial pressure. Reminding patients that stent placement is rare anyways.

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