A tissue heart valve made from pig heart valve tissue lasts approximately eight to 20 years, states St. Jude Medical. The length of time depends on factors including the patient's lifestyle, age, medications and tissue valve type. Studies show aortic valves are typically more durable than mitral valves.
Mechanical valves generally last longer than tissue valves. However, using a tissue valve eliminates the patient's need to take blood thinner medication, which is a life-long requirement for mechanical valve recipients, notes St. Jude Medical. Surgeons use tissues from pig or cow heart valves for human implantation because they function like valves of the human heart. The animal tissue is chemically treated after it is removed. The treatment protects the tissue and helps prevent adverse reactions once it is implanted.