Platinum-chromium alloy used for flexible coronary stents

A novel platinum-chromium (PtCr) alloy is being used to make more flexible and comfortable coronary stents.

Metallurgists at the US Office of Fossil Energy’s National Energy Technology Laboratory (NETL) have helped develop the device, which allows easier placement by the doctor and more safety for the patient.  

A coronary stent is a small, expandable mesh tube that is placed in a narrowed or weakened coronary artery, allowing the passageway to stay open. Every year, coronary stents save thousands of lives by expanding diseased arteries and allowing blood to flow freely.

The PtCr alloy solves many of the past problems surrounding traditional stainless steel stents.

The addition of platinum allows the stent to be thin and visible on X-ray, a problem with stainless steel stents, and its high melting also gives the stent a higher corrosion resistance, which optimises long-term stability within the body.

Meanwhile, the alloy’s flexibility allows easier movement through arterial bends without causing damage and decreasing recoil, which reduces the likelihood of constriction after deployment.

NETL’s involvement in the project goes back more than 10 years, when scientists at Boston Scientific requested the laboratory’s help with research to improve the traditional 316L stainless steel traditionally used in coronary stents.

Over the next decade, NETL and Boston Scientific researchers worked together to design the PtCr alloy and develop the process methodology to produce the alloy for use as stent material.

After many clinical trials, Boston Scientific’s various stents incorporating PtCr alloys have now come to market.