Short - Term Safety And Efficacy Of Complete Degradable Poly - L - Lactic Acid Coronary Stent And Its Effect On Vascular Compliance

(Part One)Consecutive IVUS Assessment of acute recoil of fully bioabsorbable poly-L-lactic acid scaffold within1month in porcine modelObjectiveTo assess acute recoil of fully bioabsorbable poly-L-lactic acid XINSORB scaffold within one month in porcine model.MethodsXINSORB scaffold and metallic EXCEL stent were randomly implanted into porcine coronary arteries. Angiography and IVUS were performed immediately (0hour) and2,4and6hours after implantation. IVUS was repeated at4weeks follow-up. Upon QCA, acute absolute recoil (AAR) of diameter was defined as the difference between mean diameter of inflated balloon and mean diameter of stent immediately and2,4and6hours after deployment, while acute percent recoil (APR) of diameter was defined as the ratio of AAR and diameter of balloon and expressed as a percentage. Upon IVUS, AAR of area was defined as the difference between mean area of stent immediately after deployment and mean stent area at2,4,6hours and4weeks follow-up, while APR of area was defined as the ratio of AAR and mean stent area at follow-up and expressed as a percentage.ResultsTotal16pigs were enrolled and32stents were implanted (XINSORB=16, EXCEL=16). No sign of stent malapposition was detected during the study. AAR and APR of diameter in XINSORB group at0,2,4and6hour were (0.05±0.06)mm,(1.72±1.78)%;(0.10±0.07)mm,(3.34±2.43)%;(0.08±0.06)mm,(2.59±1.89)%and (0.09±0.05)mm,(2.99±1.69)%, respectively. The counterpart in EXCEL group was (0.02±0.06)mm,(0.58±2.02)%;(0.06±0.10)mm,(2.17±3.30)%;(0.07±0.08)mm,(2.19±2.72)%and (0.07±0.09)mm,(2.41±2.76)%, respectively. AAR and APR of area of XINSORB group at2,4,6hour and4weeks was (0.05±0.13)mm2,(0.62±1.90)%;(0.04±0.35)mm2,(0.29±4.95)%;(0.22±0.46)mm2,(2.87±6.65)%and (0.31±0.27)mm2,(4.30±3.66)%,respectively. The counterpart in EXCEL group was (0.01±0.11)mm2,(0.04±1.59)%;(-0.03±0.36)mm2,(-0.44±5.34)%;(0.08±0.23)mm2,(1.02±3.41)%and (0.10±0.22)mm2,(1.44±3.35)%, respectively. Neither AAR nor APR was found significantly different between two groups. No sign of stent malloppsition was detected in both groups by IVUS.ConclusionsNo acute recoil of XINSORB scaffold was detected within one month in porcine model. The extent of acute recoil of XINSORB scaffold was similar to that of metallic EXCEL stent. Both stents were well positioned. (Part Two)Assessment of short-term safety and efficacy of fully bioabsorbable poly-L-lactic acid scaffold in porcine modelObjectiveTo assess short-term safety and efficacy of fully bioabsorbable poly-L-lactic acid XINSORB scaffold within1month in porcine model.MethodsXINSORB scaffold and metallic FIREBIRD2stent were randomly implanted into porcine coronary arteries. Neointima thickness(NT),neointima area (NA) percentage of area stenosis (%AS),injury index(Ⅱ) and degree of endothelialization were assessed by histomorphology and scanning electron microscope(SEM) at14-day and28-day in order to assess the short-term safety and efficacy of the two groups.ResultsThere was no statistically difference between the two groups regarding NT,NA,%AS and Ⅱ during the follow-up. There was no difference in inflammatory and endothelialization between the two groups during the term.ConclusionsThe short-term safety and efficacy of ploy-L-lactic acid Xinsorb scaffold was not inferior to Firebird2stent. (Part Three)Influence of poly-L-lactic acid scaffold and cobalt-chromium alloy stent on compliance of abdominal aortaObjectiveTo assess the inflence of poly-L-lactic acid scaffold and cobalt-chromium alloy(CoCu) stent on compliance of abdominal aorta. And to find out the time-course of the compliance of the poly-L-lactic acid scaffold during the degrading process.MethodsXinsorb scaffold and CoCu stent were implanted into abdominal aorta of rabbit. Compliance of abdomina aorta containing scaffold would be tested by BioDynamicTM Test Instruments (BOSE) and calculated according to the equation of C (%/100mmHg)=(R2-R1)×10∧4/R1×(P2-P1) in which P2and P1meaning the highest and lowest pressure and R2and R1meaning the correspongding artery radius at1-month,6-month and12-month after stenting.ResultsUnder pressure of20-30mmHg,30-40mmHg,40-50mmHg the compliance of abdominal aorta near diaphragm without stent were15.262,13.367,9.920respectively, and abdominal aorta approaching mid-abdomen without scaffold were8.449,8.457,6.592, meanwhile the compliance of poly-L-lactic acid scaffold and CoCu stent were2.733,1.928,2.871and4.104,2.790,2.066respectively.ConclusionsThere was potential superiority for poly-L-lactic acid scaffold on compliance under the condition near physiological pressure and it needed more studies to confirm.