3. PAD, is a term that covers an array of medical problems caused by obstruction of the large arteries in the arms or legs. In the advanced form of PAD, critical limb ischemia (CLI) can occur, which is a leading cause of lower limb amputations. The Angiogenesis Foundation estimates that 1.4 million people in the United States have CLI, with an estimated 350,876 new cases diagnosed each year (2).