Nickel and chromium release from stents into isotonic NaCl solution investigated with the aid of neutron activation analysis

Stent placement has become an effective treatment for abrupt or threatened vessel closure in recent years. As a preliminary investigation on the aller gy problem towards to Ni and Cr metals from implanted stent, the release of the two elements from stents into isotonic NaCl solution was investigated. Trace amounts of Ni and Cr metals released from stents are successfully de termined by neutron activation analysis (NAA). An extreme experimental cond ition is applied in the NAA procedure to reach a low detection limit of 1 n g Ni. A conclusion is given about the influence on the Ni and Cr release fr om gold coating, from the expansion, and from the different incubation peri ods.