Strength, Elasticity, and Plasticity of Expandable Metal Stents: In Vitro Studies with Three Types of Stress

Mechanical Characteristics of Self-expandable Metallic Stents: In Vitro Study with Three of Stress

“…The Wallstent and GianturcoRösch Z stent showed somewhat lower expandability under all stresses. These results coincide with those of a study by Flueckiger et al (9). With regard to expandability itself, the Memotherm stent has an advantage in focal eccentric and concentric stenosis, the Ultraflex stent in diffuse eccentric stenosis, and the 6 mm-band Hanaro stent in all types ofstenosis.…”

Stent Fracture, Valve Dysfunction, and Right Ventricular Outflow Tract Reintervention After Transcatheter Pulmonary Valve Implantation

“…8 However, analytic simulations of stent strength are typically based on idealized conditions. 9,10 Using patient-specific modeling, Schievano et al demonstrated that the geometry of the deployed Melody valve in the RVOT may not be ideal; thus, the assumptions used during standard radial strength testing may substantially underestimate in vivo stent loading conditions. 9 -11 In accordance with the theoretical benefit of implanting multiple stents to increase radial strength, "prestenting" the conduit with BMS or covered stents before TPV placement has become routine at many centers.…”

Physical Properties of Endovascular Stents: An Experimental Comparison

“…In 1993, a study concerning the pressure stability of metal stents had been unable to precisely quantify the hoop strength of the Palmaz stent, and had been dealing with vascular endoprostheses that are no longer in general use, such as the Strecker stent (19). In 1994, Flueckiger and coworkers reported exact data about the mechanical characteristics of metal stents (20). However, the authors could only consider stent designs t hat had been available at that time (Palmaz large stent, Wallstent, and Strecker stent).…”

“…Although the stent type, stent diameter, and method of testing have been different, these values are well in accordance with our test resul t of 0.39 N/cm for the radial resistive force of a Wallstent (fully expanded diameter, 8 mm). Of course, different test set-ups will yield conflicting results about the radial resistive force of the Wallstent because the specific stent design dictates that the radial resistance to eecentric forces will be lowered when the stent loses close contact with the entire circumference of the vessel wall (20). In addition, the older narrow braid (more shortening version) would have yielded a higher radial resistive force, especially in the case of fixed stent ends.…”