From the Guidelines
Metallic prosthetic valves are primarily made of pyrolytic carbon, titanium, and various metal alloys, including medical-grade stainless steel, cobalt-chromium alloys, and titanium alloys. The housing or frame of these valves is typically constructed from these metal alloys, while the leaflets or occluders that actually open and close are often made of pyrolytic carbon, which is extremely durable and has excellent blood compatibility 1. Some valves incorporate a combination of materials, with metal frames supporting carbon components. These materials are specifically chosen for their durability, strength, biocompatibility, and resistance to corrosion when exposed to blood flow.
Key Materials
- Pyrolytic carbon
- Titanium
- Medical-grade stainless steel
- Cobalt-chromium alloys
- Titanium alloys The exceptional durability of these materials allows metallic prosthetic valves to last 20-30 years or longer, making them particularly suitable for younger patients. However, this durability comes with the requirement for lifelong anticoagulation therapy to prevent blood clots from forming on the valve surfaces, as recommended by recent guidelines 1.
Valve Construction
- Housing or frame: metal alloys
- Leaflets or occluders: pyrolytic carbon It is worth noting that the choice of material for the valve construction is critical to ensure the longevity and functionality of the prosthetic valve, and the most recent studies support the use of these materials for their excellent properties 1.
From the Research
Materials Used in Metallic Prosthetic Valves
- Metallic prosthetic valves are made from various materials, including:
- Stainless steel: although it is the least corrosion resistant and used for temporary implants only 2
- Cobalt-chromium alloys: which do not corrode in the body but metal ions slowly diffuse through the oxide layer and accumulate in the tissue 2
- Titanium-based alloys: which also do not corrode in the body and have superior fracture and fatigue resistance, making them suitable for load-bearing applications 2
- The choice of material depends on the specific requirements of the implant and the patient's needs
- Biocompatibility and corrosion resistance are key considerations in the selection of materials for metallic prosthetic valves 2
Properties of Metallic Materials
- The performance of metallic materials in the human body is controlled by their biofunctionality and biocompatibility 2
- Corrosion resistance is a critical aspect of biocompatibility, and materials like titanium and cobalt-chromium alloys have a thin surface layer of oxide that provides passivation 2
- The accumulation of metal ions in the tissue and the formation of a fibrous layer around the implant are also important considerations 2