Small diameter (< 6 mm) vascular grafts are in large demand for coronary and peripheral bypass procedures. Although synthetic grafts have been developed, tissue-based vascular grafts that can better mimic native vessels will likely yield superior results. The success of a tissue-based graft depends on its ability to meet several requirements. First, a graft must possess a confluent, adherent and quiescent endothelium to resist thrombosis in vivo. The mechanical behavior of the graft must mimic the mechanical properties of a native vessel. Hence, a graft must have a highly organized collagen matrix to impart tissue strength. Finally, a graft must contain an elastin network to provide compliance and recoil. (C) 2003 Elsevier Inc. All rights reserved.