ELECTROCHEMICAL STUDY FOR THE EVALUATION OF CORROSION OF A NEW CERAMIC STENT.

NAVARRO, LUCILA; LUNA, JULIO; VETCHER, DAVID; MOLES, VICTOR; DUFFO, GUSTAVO; RINTOUL, IGNACIO

Congreso; Transcatheter Cardiovascular Therapeutics; 2014

ELECTROCHEMICAL STUDY FOR THE EVALUATION OF CORROSION OF A NEW CERAMIC STENT. NAVARRO, Lucila. DUFFO, Gustavo. LUNA, Julio. VETCHER, David. RINTOUL, Ignacio. MOLES, Victor. Metallic coronary stents are placed in a high chloride environment that plays an important role on the corrosion behavior of the implant. Corrosion of stents presents two main risks: release of metallic ions into the tissue and deterioration of the mechanical properties of stents. Release of heavy metal ions could affect the local tissue leading to inflammatory mediators and promote in-stent restenosis. METHODS: We evaluated the corrosion resistance of a ceramic stent (CST) developed with an innovative surface treatment that involves a multistage immersion in different solutions performed at INTEC-Universidad Nacional del Litoral and compared it with a plain stainless steel stent (SST), and a chromium-cobalt stent (CrCo). The stents were evaluated with potentiodynamic polarization studies, unexpanded and after balloon expansion at 12 bars. The corrosion potential (Ecorr) was measured under a virtual open circuit condition, with respect to a reference electrode; and the corrosion current (icorr) by a potentiodynamic polarization curve measurement, that involved scanning the potential (mV) at a rate of 0.5 mV/s to a final potential of 1.4 V. Micrographic pictures were taken before and after the electrochemical analysis to evaluate the type of corrosion. Statistical analysis: assays were done in duplicate; ANOVA and a multiple range test by Duncan´s variation were performed. RESULTS. The potentiodynamic curves of CST stents exhibited an anodic current density significantly lower than SST and Cr-Co stents. SST Cr-Co CST P Ecorr (v) -0.39 -0.617 -0.523 P