Researchers from the University of Pennsylvania in Philadelphia, USA, have developed a way to "grow' arteries that could save several heart patients' lives. The standard procedure till today is to replace diseased coronary arteries with minor arteries from elsewhere. But the test was to find the ones that was long enough. Valerie Clerin and colleagues have made arteries by putting segments in a nutrient-rich solution and stretching them a bit more each day. "We can double the length of the arteries in nine days,' she says.