 - Some people who need a transcatheter aortic valve replacement TAVR have leg arteries that are too small and are too sick for standard techniques. But they may benefit from a new technique called transcaval TAVR. For this technique, doctors make a hole between the largest vein vena cava and largest artery aorta in the body, inside the abdomen. Then they replace the valve through a tube they put in the groin vein. Then they close the hole between the vein and the artery using a device designed to close holes in the heart. This study tests the device for this new, off-label use. 