Peripheral Vascular Disease

Peripheral vascular disease (PVD), which is sometimes referred to as peripheral arterial disease (PAD), is characterized by chronic poor blood flow in the lower extremities, which can cause pain, ischemic lesions or ulcers, and sepsis. Over time this condition can progress to critical limb ischemia, and eventually lead to limb amputation. According to the 2010 American Heart Association annual statistical report on heart disease, approximately 8 million Americans have PVD, and suffer significant morbidity and mortality as a result. In 2004, the direct and indirect costs of treating PVD were estimated to be over $2 billion dollars annually in the United States alone.

Current treatment of PVD depends on the severity of the disease. Current approaches include treatment to reduce risk factors, drug therapy to reduce clotting and plaque formation, or surgical intervention in an attempt to revascularize the region of ischemic damage. However, many of the approved pharmaceutical interventions have significant side effects, and many patients are unfit candidates for revascularization due to advanced age, advanced ischemia or the presence of other complicating conditions. Additionally, revascularization is only successful 44% of the time.

Recent studies suggest that an increase in the collateral vascular network may offer protection from ischemic episodes. Collaterals normally form, remodel and enlarge around the site of blockage allowing blood flow to bypass the occluded artery and allow perfusion of the ischemic tissue. However, naturally occurring collateral development is adversely affect by age, hypercholesterolemia, diabetes and smoking and is insufficient to support adequate blood flow to the affected tissues in many PVD patients, especially during exertion.