Polymeric Biomaterials for Vascular Tissue Engineering
The total need for vascular grafts has been estimated to be more than 1.4 million in the United States alone (Niklason and Langer 1997). This need can be divided into three categories, in order of decreasing diameter (Table 3.1). The large-and medium-caliber synthetic grafts (>6-mm diameter) are used in the thoracic and abdominal cavities with good long-term outcomes. Common applications include replacement of the aorta, carotid artery, arch vessels, and iliac and femoral arteries. However, synthetic grafts of smaller diameter do not share the same outcomes and fail relatively early due to occlusion. Since tissue engineering holds great potential for development of viable grafts, this chapter delves into research and development of small-diameter vascular grafts using natural polymers.