Revisiting SFA stent technology: an updated overview on mechanical stent performance

Objectives The study investigated mechanical parameters of stent systems indicated for treatment of femoropopliteal (FP) arterial disease to support interpretation of clinical results and the related causalities. Methods Eight stent system types of same dimensions were investigated (n=2). Parameters were the profile of stent delivery system (SDS), radiopacity, trackability and pushability, bending stiffness (flexibility) and axial stiffness of expanded stents, length change during expansion, radial force, crush resistance, strut thickness and general surface condition. Results The trackability ranged from 0.237 to 0.920 N and the pushability was 47.9–67.6 %. The bending stiffness of SDS was between 108.42 and 412.68 N mm2. The length change during stent release to 5 mm was low, with one exception. The bending stiffness of the expanded stents was 2.73–41.67 N mm2. The normalized radial forces at 5 mm diameter ranged from 0.133 N/mm to 0.503 N/mm. During non-radial compression by 50 %, the forces were 3.07–8.42 N, with one exception (58.7 N). The strut thickness was 153–231 µm. Conclusions Large differences occurred for flexibility, radial force and length change during expansion. The data should be used when choosing the proper device for restoring vascular function.