Open Surgery

Peripheral Vasculature - Arteriovenous Fistula, Arteriovenous Graft
Peripheral Vasculature – Peripheral Arterial Disease (PAD)
Minimally Invasive - Peripheral Vascular Applications

Peripheral Vasculature – Arteriovenous Fistula, Arteriovenous Graft

It is known that endothelial cells release a wide variety of factors that in combination regulate the vascular response to injury. However, because the response to vascular injury is a complex process, involving many growth factors with dynamic cell to cell interactions, the identification of a single or combination of endothelial cell products to treat vascular injury is very difficult. This is particularly true in patients with ESRD, a population at risk for vascular access dysfunction. This patient group is in need of a therapy option that extends the longevity of the AVG or AVF access site, allowing for blood flow rates to support the dialysis treatment. Currently, there are no approved products to decrease access failure.

To address this unmet medical need, Vascugel® is placed adjacent to the site of injury to provide sustained and regulated release of many inhibitory endothelial cellular factors important for maintaining patency of the access site. As the native endothelium is able to maintain and regulate blood vessel wall homeostasis in a healthy vessel, Vascugel® utilizes the same endothelial cell biology in a matrix to secrete proteins and other factors for local delivery to the site of injury.

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Peripheral Vasculature – Peripheral Arterial Disease (PAD)

Peripheral Arterial Disease (PAD) affects between 8 million to 12 million people in the U.S. perhaps as many as 20 million.

Up to 30% of patients with PAD will die within 5 years, increasing to 50% after 10 years. Existing therapeutic agents include life style change, claudication agents, anti-hypertensives, lipid lowering agents, and/or anti-platelet therapy.

PAD is currently a large, under-treated medical condition in the U.S., with approximately 3.2 million peripheral vascular procedures performed annually, including minimally invasive procedures such as stent placement, and open surgical procedures such as bypass.

Interventions associated with PAD include:

• Peripheral bypass procedures using a native vein or synthetic graft result in stenoses / occlusions and ultimately failure - approximately 30% of vein grafts will fail at 1 year and 50% at 5 years, approximately 90% of synthetic grafts will fail at 5 years. Balloon angioplasty and stents can be used to treat bypass stenoses (see below).
  
  
• Balloon angioplasty in the periphery have restenosis rates of approximately 40-50%
  
  
• Stents are less frequently used in PAD and have restenosis rates of approximately 40-50%. Stents are rarely used at or below the knee due to issues of stent fracture and poor outcomes.
  
  
• Superficial femoral artery (SFA) disease is especially problematic as stents have very low patency rates and there are no available solutions.
  
  
• Artherectomy devices are not used very frequently in the periphery, and have high restenosis rates.
  

There are currently no approved products that address peripheral bypass failures. Vascugel® is a potential novel cell therapy product for the improvement of bypass graft failure. It is known that endothelial cells release a wide variety of agents that in combination inhibit stenosis and enhance vascular healing. A method that recapitulates such physiological dosing may be useful to treat peripheral bypass failures. When placed adjacent to an injured blood vessel, Vascugel® provides local delivery of these growth regulatory compounds to the underlying blood vessel. Vascugel® is unique in that the viable endothelial cells within the matrix are able to supply to injured arteries and veins multiple endothelial cell-based products in physiological proportions under physiological feed-back control. Vascugel®, when placed adjacent to a target site of vessel injury, i.e., the anastomosis and/or vein, will serve to reestablish homeostasis.

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Minimally Invasive - Peripheral Vascular Applications

Vascular access failure is the major complication in providing care to patients on hemodialysis to treat end stage renal disease (ESRD). The prevalent dialysis population reached nearly 336,000 in 2004. Approximately 310,000 of the prevalent ESRD population were treated with hemodialysis (1,008 per million population) in 2004. Total Medicare ESRD costs reached $20.1 billion (6.8 % of the entire Medicare budget), with 16.3 billion spent on the provision of dialysis. Non-Medicare costs reached 12.4 billion. The annual cost of vascular access related morbidity in the United States (US) may well exceed $1 billion dollars per year.

Arteriovenous fistulae and grafts frequently develop stenoses and occlusions at the anastomoses, commonly on the venous anastomotic side. The current therapy for vascular access stenosis is either surgical revision or angioplasty with or without stenting. Surgical treatment may be risky in these typically multi-morbid patients and the long-term results of angioplasty and stenting are generally disappointing due to failure rates of their own. Pervasis’ endothelial based technology may also be used to address this problem. In minimally invasive procedures, such as angioplasty and stenting, when injected adjacent to the site of intervention, Vascugel® provides local delivery of necessary growth regulatory compounds to the underlying blood vessel to induce healing. The injectable formulation of Vascugel® could be delivered percutaneously, or via a catheter-based delivery system, at the time of the angioplasty and/or stent intervention.

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