Clinical Background

The Clinical Need for a New Approach to Debris Removal
Peripheral vascular disease (PVD) is characterized by the narrowing or total occlusion of blood vessels outside of the heart or brain and can cause conditions including pain, loss of function and death. PVD is primarily treated by angioplasty and stenting:



Angioplasty is a non-surgical procedure in which narrowed or blocked arteries are re-opened by placing a catheter with a deflated balloon on the tip into the narrowed artery. The balloon is then inflated to compress the plaque and to stretch the artery wall, thereby enlarging or dilating the opening of the vessel and restoring blood flow.



Stents, which are tubular mesh devices typically consisting of interconnected metal struts, may be inserted inside the artery to act as scaffolding in order to hold the vessel open.



In 2006, over 1.2 million endovascular procedures to treat peripheral vascular disease were performed worldwide. During these procedures, plaque and debris may dislodge or embolize, potentially blocking blood flow and damaging distal tissue. Emboli dispersion can lead to serious clinical events, including blue toe syndrome, amputation, deterioration of renal function or renal failure, stroke, myocardial infarction and/or death (depending on the location of the procedure).



Lower Limbs
PVD in the lower limbs can cause leg pain and lead to tissue loss or amputation. In 2004 approximately 1.1 million people in the US suffered from critical limb ischemia, or CLI. In addition, within six months of diagnosis, the mortality rate for CLI patients was approximately 20%, with another 35% requiring amputation. An estimated 160,000 amputations resulting from CLI are performed each year in the US alone.

The volume of lower limbs angioplasty and stenting procedures in the US is expected to grow at a compound annual growth rate of 16.

The issue of distal embolization created by angioplasty or stenting procedures has been defined by physicians as an underestimated and critical phenomenon, and occurs in up to 8% of all procedures:

Article		Embolic Protection Need
Wholey, et al. June '07 Endovascular Today		"Is embolic debris an issue in interventions involving the femoropopliteal [lower limb] arteries? Yes, all embolic debris can be harmful to patients."
Karnabatidis, et al. Journal of Endovascular Therapy 2006		"Distal embolism is one of the most feared complications of all endovascular procedures." "According to our findings, distal atherothrombotic embolism during infra-aortic revascularization [lower limbs] procedures is frequent and underestimated"
Koenig et al. Cardiovascular Interventional Radiology 2003		"Downstream embolization is a common event during balloon angioplasty of femoropopliteal [lower limbs] stenoses."