Björk–Shiley valve

Shiley-valve

Björk–Shiley valve is a type of artificial heart valve used in heart valve surgery. This mechanical valve was developed in the 1970s by the Swedish heart surgeon Viking Björk and the American engineer Donald Shiley. It was one of the first successful mechanical heart valves and has been implanted in many patients worldwide. However, its use has been associated with certain complications, leading to its decline in popularity over the years.

Design and Function

The Björk–Shiley valve is known for its unique design, which consists of a tilting disc valve. The valve is made from pyrolytic carbon, a material chosen for its durability and biocompatibility. The design allows for the disc to open and close with each heartbeat, mimicking the action of a natural heart valve. This mechanism ensures unidirectional blood flow from one chamber of the heart to another or from the heart to the arteries.

Advantages

One of the main advantages of the Björk–Shiley valve was its durability and the low risk of thrombosis, compared to other mechanical valves available at the time of its introduction. Its design was considered revolutionary, providing patients with a long-term solution for valve replacement.

Complications and Controversies

Despite its initial success, the Björk–Shiley valve has been associated with serious complications, including valve fracture, which can lead to sudden death. The risk of valve thrombosis and embolism also necessitates the lifelong use of anticoagulants for patients with this valve, increasing the risk of bleeding. These complications have led to numerous lawsuits and the eventual recall of certain models of the valve.

Legacy

The Björk–Shiley valve played a significant role in the development of heart valve replacement therapy. It paved the way for the development of newer, safer mechanical and bioprosthetic valves. Today, while the use of the Björk–Shiley valve has decreased significantly, its impact on the field of cardiac surgery and biomedical engineering remains important.

See Also

• Heart valve surgery
• Mechanical heart valves
• Bioprosthetic valve
• Cardiac surgery
• Biomedical engineering