Potentiodynamic polarization study on electropolished nitinol vascular implants.

The electrochemical properties of electropolished Nitinol vascular implants manufactured in a serial-production manner starting with laser cutting of tubing and ending with electropolishing and final inspection were analyzed and evaluated over a time period of 1 year. Potentiodynamic polarization tests in phosphate-buffered saline were conducted on over 1250 Nitinol implants covering the entire serial production range at ADMEDES Schuessler GmbH - from tiny stents for neurovascular applications up to large heart valve frames. Breakdown potentials were evaluated and correlated to product group, properties of the semifinished material and raw material supplier. Results of this study give clear indications for the interrelation between material quality and the event of electrochemical breakdown in a potentiodynamic polarization test.