Disc failure in a Björk-Shiley mitral prosthesis

Area of Science:

• Cardiovascular Surgery
• Biomaterials Science

Background:

• Björk-Shiley spherical valves are mechanical heart valves used in cardiac surgery.
• Valve malfunction can necessitate reoperation, posing surgical risks.
• Pyrolytic carbon is a common material used in prosthetic heart valves due to its durability.

Observation:

• A 50-year-old male patient presented with a malfunctioning Björk-Shiley spherical valve.
• The valve had been implanted 14 years prior to the current presentation.
• Reoperation was performed to address the valve dysfunction.

Findings:

• Examination of the explanted Björk-Shiley valve revealed a critical finding: a missing segment of the pyrolytic carbon disc.
• Despite the structural defect, there was no evidence of embolization, meaning the detached carbon fragment did not travel to other parts of the body.
• The patient experienced a satisfactory recovery following the surgical intervention.

Implications:

• This case highlights a potential failure mode in long-term implanted Björk-Shiley spherical valves, specifically pyrolytic carbon disc fracture.
• The absence of embolization in this instance suggests that such fractures may not always lead to catastrophic embolic events.
• Further investigation into the long-term durability and failure mechanisms of mechanical heart valves is warranted to improve patient outcomes and device design.