A Pilot Study for Evaluating the Longitudinal Strength and Flexibility of Coronary Stents: Results of a Bench Test (Original)

Aim : Longitudinal stent deformation (LSD) in second-generation stent platforms has been recently reported. Because LSD is becoming a stent selection factor, we performed an in vitro bench test to understand the mechanism and relationship between LSD and stent flexibility. Methods and Results : Two tests were conducted using three different second-generation drugeluting stents (DESs) : PROMUS Element, Xience Prime and Resolute Integrity. Test 1 : Stents in a malapposed vessel model were compressed with 0.5 N and 1.0 N using a force machine, and the degree of stent deformation was evaluated. Test 2 : Stents were placed at 10 degrees in a U-tube vessel model, and the angle change before and after stent deployment was evaluated. Only the PROMUS Element showed some degree of LSD with 0.5 N, and all three stents showed some degree of LSD with 1.0 N. The degree of LSD was smallest with the Resolute Integrity stent, and the degree of angle change was 30°, 46° and 56° for the PROMUS Element, Xience Prime and Resolute Integrity stents, respectively. Conclusions : This pilot study showed a relationship between stent longitudinal strength and flexibility. It is necessary to understand the features of each stent platform and use them to select the appropriate stent depending on various lesion characteristics. (Jikeikai Med J 2015 ; 62 : 9-13)