The Ross Procedure is a type of specialized aortic valve surgery in which the patient's diseased aortic valve is replaced with his or her own pulmonary valve. The pulmonary valve is then replaced with cryopreserved cadaveric pulmonary valve (a valve taken from a cadaver that is preserved by freezing). In children and young adults, or older particularly active patients, this procedure offers several advantages over traditional aortic valve replacement with manufactured prostheses, which require the use of blood thinners, or bioprostheses, such as pig valves, which tend to degenerate after only a few years in patients under 35 years of age.