Evaluation Of The Safety And Efficacy Of A New Fully Bioresorbable Vascular Scaffold Covered With Biodegradable Poly-L-lactic Acid Film In Rabbits

Background: Coronary artery perforation(CAP)is a severe or fatal complication of percutaneous coronary interventions(PCI).The covered stent is the mainstay for treatment of CAP.However,present covered stents have poor clinical outcomes due to its non-degradation nature.In order to provide biosafe and effective bioresorbable covered stent for clinical practice,we together with Micro Port Medical Company(Shanghai,China),firstly developed and manufactured a new fully Bioresorbable Vascular Scaffold covered with biodegradable poly-L-lactic acid film(BVS-C).In our in vitro tests,various parameters of BVS-C were superior to the existing covered stents.However,the biosafety and effectiveness of BVS-C remains unclear.Objective: This study aims to evaluate the biosafety and efficacy of BVS-C in experimental rabbits.Methods: BVS-C was deployed at the zone of target artery(abdominal aorta to right iliac artery)in anesthetized New Zealand white rabbits.Post-procedural angiography was executed to evaluate whether sealing re-opening of left iliac artery or not.Six months after stent implantation,angiography of the target artery was conducted to evaluate the biosafety and biodegradability of BVS-C.Meanwhile,optical coherence tomography(OCT),histological light microscopy(HLM)and scan electron microscopy(SEM)were performed to evaluate the endothelialization of BVS-C,the degradation of covered membrane and the incidence of stent thrombosis.Results: Five BVS-C were successfully implanted in the left iliac artery in all rabbits without procedure-related complications.All rabbits were accomplished follow-up.The immediately post-procedural angiography showed that BVS-C had sealed the ostia of left iliac artery in all rabbits,without blood flow in left iliac artery and its branches.The angiograms at 6 months revealed that the membrane of BVS-C had almost fully degraded,the left iliac artery and its branches was reopening with restoration of blood flow.The images of OCT noted that the membrane of BVS-C had nearly completely degraded,with excellent endothelialization and no thrombosis.The results of HLM and SEM further confirmed the findings of OCT.Conclusions: BVS-C is safe,efficacious with biodegradability in rabbits,and may be promising for future clinical applications.