Abstract:

Aim: was to evaluate mechanical properties of coronary stent «SINUS» and compare them with mechanical properties of coronary stents of foreign production.

Material and methods: experimental group included coronary stents «SINUS», made of cobalt-chromium alloy L605 laser cut (H design and L2). The comparison group included stents: MULTI-LINK Vision, MULTI-LINK 8 (Abbott Vascular), Presillion (Cordis, Medinol), Integrity (Medtronic). With the help of certified device tests were conducted on all stents: passage (ability to overcome the delivery system for corners) , the geometrical uniformity of diameter upon radial stability, rigidity on the long axis, the amount of self-reducing the diameter after removal of the pressure in the balloon («Recoil»); in relation to stents "SINUS" independent testing laboratory DynatekLabs (USA) was carried out endurance test under pulsating radial exposure for 380 million cycles in accordance with ASTM F2477-07, required to obtain the approval of FDA USA.

Results: а stents were successfully tested for passage through an angle of 90° with the radius of rotation from 30 mm to 7.5 mm. Indicator geometric irregularities along the length of the stent diameter for all stents in the range ±1,5%, which corresponds to the measurement error. Test results radial stability upon compression up to 80% of the nominal diameter of the stent have been least Multi-Link Vision 0,28±0,02 N / mm and the highest in stent Integrity 0,65±0,02 N/mm. Test results for radial stability of the stent, «SINUS» with H-design is similar to the results for the Multi-Link stent and stent 8 Presillion 0,37±0,02 N/mm , and the stent, «SINUS» with L2- close design 0.52±0,02 N/mm . Test results on the ability to repeat the curved shape of the stent showed the smallest vessel in stent rigidity «Sinus» H-design, the highest in the stent Multi-Link 8. Remaining stents ascending rigidity «SINUS» L2- design , Presillion, Integrity, Multi-Link Vision. Test «Recoil» showed the lowest value of 4.5% in the stent Multi-Link Vision, the largest in Multi-Link stent 8-5.4% , the variation of this parameter between stents insignificant - ±0,5%, within the error of measurement of diameter due to the complex geometry of the stent. Test results have shown persistence DynatekLabs mechanical integrity of the structure and the absence of stent migration«SINUS» after 380 million cycles (equivalent to 10 years of implantation with an average heart rate = 72 beats/min) radial pulsating effects .

Conclusion: this study showed that stents «SINUS» have significant differences from the comparison group of stents in terms of: Recoil, passage of 90° angular rotation, uniform diameter disclosed stent radial strength fatigue. In terms of radial stability stents «SINUS» meet or exceed stents comparison groups, second only to the stent «Integrity». In terms of adaptability, in the open state , the curved profile of the vessel stents «SINUS» have the best performance with respect to comparison groups. 

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