Vascular Graft 1 (IMAGE) Virginia Commonwealth University Caption A short tube, which has an internal diameter of 1.5 mm compared to a penny. The tube is being used in aorta replacement studies being conducted by B.H. Walpoth, M.D., who contributed to this work. Credit Photo courtesy of David G. Simpson, Ph.D./VCU Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.