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Physical Properties of Endovascular Stents: An Experimental Comparison

2000; Elsevier BV; Volume: 11; Issue: 5 Linguagem: Inglês

10.1016/s1051-0443(07)61620-0

1535-7732

Stephan H. Duda, Jakub Wiskirchen, Gunnar Tepe, Michael Bitzer, Theodor W. Kaulich, Dieter Stoeckel, Claus D. Claussen,

Peripheral Artery Disease Management

PURPOSE Different endovascular stent types (AVE Bridge, AVE Bridge X, Memotherm, Palmaz Large, Palmaz Medium, Palmaz-Schatz Long-Medium, Perflex, S.M.A.R.T., Symphony, and Wall-stent) of 4 cm length and 8 mm diameter were subjected to standardized physical tests. MATERIALS AND METHODS The metal mass of each stent was assessed by weighing. The balloon-expandable stents were pneumatically tested for hoop strength. In self-expanding stents, radial resistive force and chronic outward force were determined with use of a loop test. Stent delivery system pushability was assessed in a crossover model. Stent radiopacity was analyzed quantitatively. RESULTS The hoop strength of the balloon-expandable stents ranged from 15.8 N/cm (Perflex) to 28.9 N/cm (AVE Bridge X). The stent weight increased with greater hoop strength (Perflex, 0.046 g/cm vs. AVE Bridge X, 0.061 g/cm). The self-expanding stents had a radial resistive force between 0.39 N/cm (Wallstent) and 1.7 N/cm (Smart). The flexible balloon-expandable stents showed pushability values between 0.13/N (AVE Bridge) and 0.20/N (Perflex). The self-expanding stents had flexibilities between 0.13/N (Memotherm) and 0.24/N (Symphony). Radiopacity assessed with use of a phantom simulating the iliac region ranged from 92 (Palmaz Large) to 115 (AVE Bridge) on a 256-point gray scale (0 = black, 256=white). CONCLUSIONS There is no stent with ideal physical properties. However, depending on the characteristics of the arterial lesion to be treated, the most appropriate stent can be chosen.