BACKGROUND Bioresorbable scaffolds(BRS)are a promising alternative to traditional drugeluting stents(DES)for the treatment of acute coronary syndrome(ACS).They offer the potential for complete resorption,which may red...BACKGROUND Bioresorbable scaffolds(BRS)are a promising alternative to traditional drugeluting stents(DES)for the treatment of acute coronary syndrome(ACS).They offer the potential for complete resorption,which may reduce long-term complications such as stent thrombosis and late restenosis.However,the safety,compatibility,and long-term outcomes of BRS in patients with intermediate to low-risk ACS have yet to be thoroughly investigated.AIM To investigate the safety,compatibility,and long-term outcomes of BRS in patients with intermediate to low-risk ACS.METHODS Patients with intermediate to low-risk ACS who underwent percutaneous coronary intervention with either DES or BRS,and were continuously recruited from January 2019 to June 2022 at a single center,were analyzed.Baseline data and clinical follow-up were collected for patients who underwent DES implantation(control group)and BRS implantation(observation group),and the survival outcomes and complications during a maximum follow-up period of 3 years were compared.The primary clinical endpoint was device-oriented composite endpoint(DoCE),representing the occurrence of one of the following events:Cardiac death,stent thrombosis,target vessel myocardial infarction,and clinically driven target lesion revascularization.Secondary endpoints included coronary artery bypass grafting,target vessel revascularization,and non-cardiac death.RESULTS A total of 128 patients were included in this study,with an average age of 63 years.Among them,95 were male(74%).The study involved treatment of 201 blood vessels:87(43%)received BRS,and 114(57%)received DES.A total of 97 patients completed the full 3-year follow-up.During this period,5 patients(17%)in the observation group and 7 patients(16%)in the control group experienced a major cardiovascular event(DoCE).At the 1-year follow-up,7 patients(15%)in the observation group and 6 patients(10%)in the control group experienced DoCE,and this difference was statistically significant(P<0.05).At the 2-year follow-up,there was also a significant difference between the two groups in the number of patients who needed repeat treatment of the target blood vessel(P<0.05).In the observation group,18 patients(33%)underwent follow-up coronary angiography.During the follow-up period,one patient in the observation group was found to have re-narrowing in the proximal and middle segments of the left anterior descending artery,possibly due to BRS collapse.Another patient in the observation group developed chronic total occlusion in multiple vessels at the 3-year follow-up and underwent coronary artery bypass grafting.CONCLUSION In low-to intermediate-risk ACS patients,those who got BRS had their first major heart event sooner than those who got DES.BRS is more tissue-friendly,yet over three years both groups had about the same amount of problems-only a few BRS patients still saw the scaffold collapse or the vessel slowly block.展开更多
BACKGROUND With the development of percutaneous coronary intervention(PCI),the number of interventional procedures without implantation,such as bioresorbable stents(BRS)and drug-coated balloons,has increased annually....BACKGROUND With the development of percutaneous coronary intervention(PCI),the number of interventional procedures without implantation,such as bioresorbable stents(BRS)and drug-coated balloons,has increased annually.Metal drug-eluting stent unloading is one of the most common clinical complications.Comparatively,BRS detachment is more concealed and harmful,but has yet to be reported in clinical research.In this study,we report a case of BRS unloading and successful rescue.This is a case of a 59-year-old male with the following medical history:“Type 2 diabetes mellitus”for 2 years,maintained with metformin extended-release tablets,1 g PO BID;“hypertension”for 20 years,with long-term use of metoprolol sustained-release tablets,47.5 mg PO QD;“hyperlipidemia”for 20 years,without regular medication.He was admitted to the emergency department of our hospital due to intermittent chest pain lasting 18 hours,on February 20,2022 at 15:35.Electrocardiogram results showed sinus rhythm,ST-segment elevation in leads I and avL,and poor R-wave progression in leads V1–3.High-sensitivity troponin I level was 4.59 ng/mL,indicating an acute high lateral wall myocardial infarction.The patient’s family requested treatment with BRS,without implanta-tion.During PCI,the BRS became unloaded but was successfully rescued.The patient was followed up for 2 years;he had no episodes of angina pectoris and was in generally good condition.CONCLUSION We describe a case of a 59-year-old male experienced BRS unloading and successful rescue.By analyzing images,the causes of BRS unloading and the treatment plan are discussed to provide insights for BRS release operations.We discuss preventive measures for BRS unloading.展开更多
The evolution of coronary intervention techniques and equipment has led to more sophisticated procedures for the treatment of highly complex lesions.However,as a result,the risk of complications has increased,which ar...The evolution of coronary intervention techniques and equipment has led to more sophisticated procedures for the treatment of highly complex lesions.However,as a result,the risk of complications has increased,which are mostly iatrogenic and often include equipment failure.Stent dislodgement warrants vigilance for the early diagnosis and a stepwise management approach is required to either expand or retrieve the lost stent.In the era of bioresorbable scaffolds that are not radiopaque,increased caution is required.Intravascular imaging may assist in detecting the lost scaffold in cases of no visibility fluoroscopically.Adequate lesion preparation is the key to minimizing the possibility of equipment loss;however,in the case that it occurs,commercially available and improvised devices and techniques may be applied.展开更多
In this letter,we comment on a recent case report by Sun et al in the World Journal of Cardiology.The report describes the successful management of a rare complication:The unloading or detachment of a bioresorbable st...In this letter,we comment on a recent case report by Sun et al in the World Journal of Cardiology.The report describes the successful management of a rare complication:The unloading or detachment of a bioresorbable stent(BRS)during percutaneous coronary intervention(PCI)in a male patient.The unloading of BRS was detected via angiography and intravascular ultrasound(IVUS)imaging of the left coronary artery and left anterior descending artery.Although this case is interesting,the authors’report lacked crucial details.Specifically,insufficient information about the type of BRS used,potential causes of BRS unloading,or whether optical coherence tomography(OCT)imaging for coronary arteries was performed before,during,or after PCI.The OCT imaging of coronary arteries before PCI can potentially prevent BRS unloading due to its higher resolution compared to IVUS.In addition,despite detecting myocardial bridging during the PCI,the authors did not provide any details regarding this variation.Here we discuss the various types of BRS,the importance of OCT in PCI,and the clinical relevance of myocardial bridging.展开更多
Aim. To investigate the bioactivity of the self- designed biodegradable osteosynthetic devices made of resorbable hydroxyapatite microparticles/ poly- DL- lactide (HA/PDLLA) composites. Method. Forty- three rabbits wi...Aim. To investigate the bioactivity of the self- designed biodegradable osteosynthetic devices made of resorbable hydroxyapatite microparticles/ poly- DL- lactide (HA/PDLLA) composites. Method. Forty- three rabbits with a transverse transcondylar osteotomy of the distal femur were fixed intramedullary by a HA/PDLLA rod, the duration of follow- up were 3， 6， 12, 24 and 36 weeks. Histological, scanning electron microscopic (SEM), energy dispersive X- ray (EDX) and biomechanical analyses were done. Results. Active new bone formation and direct bone- bonding were seen at the bone- implant interface. Generous apatite crystals deposited and grew on the surface of the composites at 3～ 6 weeks postoperation. The interfacial shear strength increased significantly. Conclusion. Through the incorporating of resorbable HA microparticles, specific bone- bonding and active osteogenic capacity is introduced. This kind of bioactivity, together with other properties such as sufficient mechanical strength, enhanced biocompatibility and radiopacity, which are intrinsically unobtainable in totally resorbable polymer/polymer systems, make the HA/PDLLA composites become a desirable material for the internal fixation of cancellous bone.展开更多
BACKGROUND The in-stent restenosis(ISR)rates are reportedly inconsistent despite the increased use of second-generation drug eluting stent(DES).Although bioresorbable vascular scaffold(BVS)have substantial advantages ...BACKGROUND The in-stent restenosis(ISR)rates are reportedly inconsistent despite the increased use of second-generation drug eluting stent(DES).Although bioresorbable vascular scaffold(BVS)have substantial advantages with respect to vascular restoration,the rate of scaffold thrombosis is higher with BVS than with DES.Optimal treatment strategies have not been established for DES-ISR to date.CASE SUMMARY We report on a case of a 60-year-old man patient with acute coronary syndrome.He had a history of ST-segment elevation myocardial infarction associated with very late scaffold thrombosis and treated with a DES.Coronary angiography revealed significant stenosis,suggesting DES-ISR on the previous BVS.Optical coherence tomography(OCT)identified a plaque rupture and a disrupted scaffold strut in the neointimal proliferation of DES.To treat the DES-ISR on the previous BVS,we opted for a drug-coated balloon(DCB)after a balloon angioplasty using a semi-compliant and non-compliant balloon.The patient did not experience adverse cardiovascular events on using a DCB following the use of intensive dual antiplatelet therapy and statin for 24 mo.CONCLUSION This case highlights the importance of OCT as an imaging modality for characterizing the mechanism of target lesion failure.The use of a DCB following the administration of optimal pharmacologic therapy may be an optimal strategy for the treatment and prevention of recurrent BVS thrombosis and DES-ISR.展开更多
Background Current studies,including randomized trials and meta-analyses evaluating clinical Results of bioresorbable scaffold(BRS),have raised concerns about the first-generation device with thicker struts and limite...Background Current studies,including randomized trials and meta-analyses evaluating clinical Results of bioresorbable scaffold(BRS),have raised concerns about the first-generation device with thicker struts and limited expansion capability.Newer BRS with thinner struts and improved deliverability are expected to enhance safety and efficacy profile.Bioheart(Bio-Heart,Shanghai,China)BRS is constructed from a PLLA backbone coated with a PDLLA layer eluting sirolimus.Sixmonth Results have proved preliminary safety and effectiveness of the Bioheart BRS in patients with single de novo coronary artery lesions.We sought to report serial intracoronary imaging findings at 1 year.展开更多
Background: There is a large assortment of modalities for the surgical treatment/management of distal radius fractures (DRFs), where the most widely used is the fixed-angle volar plating (VLP) system, which, sometimes...Background: There is a large assortment of modalities for the surgical treatment/management of distal radius fractures (DRFs), where the most widely used is the fixed-angle volar plating (VLP) system, which, sometimes, is referred to as the “surgical modality of choice”. While outcomes with each modality are usually good to excellent, each has its share of shortcomings and complications. Thus, there is scope for improvements to existing modalities and/or introduction of new ones. Study Purpose: We introduce a novel modality, namely, the prototype of an intramedullary injectable bioresorbable polymer-bioresorbable balloon osteosynthesis (IPBO) system, and investigated its plausibility. Experimental Procedures: The biomechanical performance of a construct comprising a synthetic distal radius (fourth-generation Sawbones?) on which a simulated fracture was created (4-mm wide osteotomy positioned 25 mm from the most distal end of the radius) and fixated with a placement of the IPBO system (SIPBO Construct) was compared to that when the fixation was with an approved Ti-6Al-4V alloy VLP system (SVLP Construct), under a clinically-relevant compressive loading protocol. Performance involved determination of quantitative parameters of the construct (initial longitudinal stiffness (ICLS), final longitudinal stiffness (FCLS), and load-to-failure (Pf)) and observation and recording of features of the construct at the fracture point. We also determined the quantitative parameters for the intact synthetic distal radius (control). Results: For each of the quantitative parameters, the range of values for SIPBO Construct was within that for SVLP Construct, suggesting that the IPBO System is a plausible modality. Also, for SIPBO Construct, failure occurred within the polymer zone, whereas, for SVLP Construct, some failure features were fracture of the cortical wall and of the dorsal proximal fragments. Conclusion: The findings suggest that the IPBO system is plausible. As such, it merits further study;for example, determination of the influence of fracture gap fill ratio (defined as the proportion of the fracture gap that is filled by the expanding balloon as the polymer is injected into the balloon) on a large collection of quantitative biomechanical parameters.展开更多
The most popular treatment/management modality for coronary artery disease, which is one of the leading causes of death, is percutaneous transluminal coronary intervention (popularly known as “plain old balloon angio...The most popular treatment/management modality for coronary artery disease, which is one of the leading causes of death, is percutaneous transluminal coronary intervention (popularly known as “plain old balloon angioplasty”) followed by implantation of a stent (“stenting”). Stent types have evolved from bare metal stents through first-generation drug-eluting stents to fully bioresorbable stents (FBRSs). Two examples of FBRSs are 1) Mg scaffold with no coating;and 2) Mg alloy scaffold coated with a bioresorbable polymer in which an anti-proliferative drug is embedded. In the case of Mg/Mg alloy FBRSs, one of the reported clinical results is that the resorption time of the stent is too short (in vivo resorption time (and, hence, improving the clinical efficacy) of the current generation of fully-bioresorbable Mg/Mg-alloy stents as well as guide the development of the next generation of these stents.展开更多
We describe the case of a patient presenting with STsegment elevation myocardial infarction due to very late scaffold thrombosis. The patient was already admitted for an elective percutaneous recanalization of a chron...We describe the case of a patient presenting with STsegment elevation myocardial infarction due to very late scaffold thrombosis. The patient was already admitted for an elective percutaneous recanalization of a chronically occluded left anterior descending artery(LAD). The procedure was performed according the subintimal tracking and re-entry(STAR) technique with 4 bioresorbable vascular scaffolds implantation. However, even though the coronary flow was preserved at the end of the procedure, the dissected segment was only partially sealed at the distal segment of the LAD. After 18 mo of regular assumption, dual antiplatelet therapy was discontinued for 10 mo before his presentation at the emergency room. This is the first reported case of a very late scaffold thrombosis after coronary chronic total occlusion(CTO) recanalization performed according to the STAR technique. This case raises concerns about the risk of very late scaffold thrombosis after complex CTO revascularization.展开更多
Objectives: This study explores feasibility of tissue-engineered osteogenesis using sterile coral implants loaded with homologous osteoblasts to repair bone defects. Study Design: A unilateral 4 mm transverse dis- con...Objectives: This study explores feasibility of tissue-engineered osteogenesis using sterile coral implants loaded with homologous osteoblasts to repair bone defects. Study Design: A unilateral 4 mm transverse dis- continuity defect was produced approximately mid-way along left radius of young female rabbits using ro- tary diamond disc under continuous saline irrigation and stabilised with autoclaved steel miniplate and screws. The defect was then fitted with sterile bioresorbable coral implant loaded with homologous neonatal calvarial osteoblasts or control implants without osteoblasts. All animals underwent radiography immedi- ately post-operative, at weekly intervals for four weeks and at fortnightly intervals thereafter. Operated bones were histologically evaluated for osteogenesis at 12 weeks. Results: Findings demonstrate osteogenesis and complete repair of bioresorbable coral implant by homologous osteoblasts loaded on coral scaffold. Conclu- sions: Single stage surgery using this technique to induce osteogenesis and closure of discontinuity bone de- fects including palatal clefts and peripheral reduction of large craniofacial defects might prove better thera- peutic modality than autologous bone grafting or tissue distraction osteogenesis.展开更多
Purpose: To report a novel technique of laparoscopic 10 mm Single Port Access IntraPeritoneal Onlay Mesh (SPA-IPOM) using bioresorbable composite mesh fixed with Endoclose suture (percutaneous subcutaneous suture) in ...Purpose: To report a novel technique of laparoscopic 10 mm Single Port Access IntraPeritoneal Onlay Mesh (SPA-IPOM) using bioresorbable composite mesh fixed with Endoclose suture (percutaneous subcutaneous suture) in 3 cases of bilateral inguinal hernia. Methods: Laparoscopic SPA-IPOM is done through a 10 mm trocar with one 10 mm instrument that has 5 mm optical lens and 5 mm channel for grasper. After inserting 10 mm trocar at umbilicus using semi-open technique, intraperitoneal anatomical landmark of inguinal her-nia is identified. A 10 × 15 cm pre-tied bioresorbable composite mesh is then placed to cover hernia defect and all three potential area of indirect, direct and femoral hernia. Using Endoclose? needle, each pair of pre-tied sutures is retrieved percutaneously through a needle wound and extracorporeal tied with knot in subcutaneous space. After the upper half of mesh is sutured to the posterior surface of abdominal wall, the lower half of mesh is fixed by hernia tacker to Symphysis Pubis, Cooper Ligament and Iliopubic tract. Re-sults: Three men, average 48 year olds were operated by laparoscopic 10 mm SPA-IPOM for bilateral in-guinal hernia repair using bioresorbable composite mesh. Average operative time was 36 minutes. No imme-diate complication. All patients were discharge on the 2nd post-operative day and average 6 months follow up has no recurrence. Conclusions: Laparoscopic SPA-IPOM is an optional operation and is much easier to be performed. Benefits include operative time saving, cosmesis, early discharge and early return to work. Bio-resorbable composite mesh prevents bowel adhesion, however, is much more expensive. Long term follow up study for complications and recurrence is needed.展开更多
Iron is considered as an attractive alternative material for bioresorbable scaffolds(BRS).The sirolimus eluting iron bioresorbable scaffold(IBS),developed by Biotyx Medical(Shenzhen,China),is the only iron-based BRS w...Iron is considered as an attractive alternative material for bioresorbable scaffolds(BRS).The sirolimus eluting iron bioresorbable scaffold(IBS),developed by Biotyx Medical(Shenzhen,China),is the only iron-based BRS with an ultrathin-wall design.The study aims to investigate the long-term efficacy,safety,biocompatibility,and lumen changes during the biodegradation process of the IBS in a porcine model.A total of 90 IBSs and 70 cobaltchromium everolimus eluting stents(EES)were randomly implanted into nonatherosclerotic coronary artery of healthy mini swine.The multimodality assessments including coronary angiography,optical coherence tomography,micro-computed tomography,magnetic resonance imaging,real-time polymerase chain reaction(PCR),and histopathological evaluations,were performed at different time points.There was no statistical difference in area stenosis between IBS group and EES group at 6 months,1year,2 years and 5 years.Although the scaffolded vessels narrowed at 9 months,expansive remodeling with increased mean lumen area was found at 3 and 5 years.The IBS struts remained intact at 6 months,and the corrosion was detectable at 9 months.At 5 years,the iron struts were completely degraded and absorbed in situ,without in-scaffold restenosis or thrombosis,lumen collapse,aneurysm formation,and chronic inflammation.No local or systemic toxicity and abnormal histopathologic manifestation were found in all experiments.Results from real-time PCR indicated that no sign of iron overload was reported in scaffolded segments.Therefore,the IBS shows comparable efficacy,safety,and biocompatibility with EES,and late lumen enlargement is considered as a unique feature in the IBS-implanted vessels.展开更多
As the world's population ages,peripheral vascular disease(PVD)has become one of the leading causes of death,caused by atherosclerosis and vascular stenosis.PVD typically affects the lower extremities,placing a si...As the world's population ages,peripheral vascular disease(PVD)has become one of the leading causes of death,caused by atherosclerosis and vascular stenosis.PVD typically affects the lower extremities,placing a significant financial burden on both individuals and healthcare systems worldwide.Open bypass surgery has traditionally been the most common treatment for PVD,but the procedure carries a high rate of perioperative adverse events.展开更多
This study aimed to investigate the long-term biocompatibility, safety, and degradation of the ultrathin nitrided iron bioresorbable scaffold (BRS) in vivo, encompassing the whole process of bioresorption in porcine c...This study aimed to investigate the long-term biocompatibility, safety, and degradation of the ultrathin nitrided iron bioresorbable scaffold (BRS) in vivo, encompassing the whole process of bioresorption in porcine coronary arteries. Fifty-two nitrided iron scaffolds (strut thickness of 70 μm) and 28 Vision Co–Cr stents were randomly implanted into coronary arteries of healthy mini-swine. The efficacy and safety of the nitrided iron scaffold were comparable with those of the Vision stentwithin 52 weeks after implantation. In addition, the long-term biocompatibility, safety, and bioresorption of the nitrided iron scaffold were evaluated by coronary angiog-raphy, optical coherence tomography, micro-computed tomography, scanning electron microscopy, energy dispersive spectrometry and histopathological evaluations at 4, 12, 26, 52 weeks and even at 7 years after im-plantation. In particular, a large number of struts were almost completely absorbed in situ at 7 years follow-up, which were first illustrated in this study. The lymphatic drainage pathway might serve as the potential clearance way of iron and its corrosion products.展开更多
This article describes the evolution of minimally invasive intervention technologies for vascular restoration therapy from early-stage balloon angioplasty in 1970s,metallic bare metal stent and metallic drug-eluting s...This article describes the evolution of minimally invasive intervention technologies for vascular restoration therapy from early-stage balloon angioplasty in 1970s,metallic bare metal stent and metallic drug-eluting stent technologies in 1990s and 2000s,to bioresorbable vascular scaffold(BVS)technology in large-scale development in recent years.The history,the current stage,the challenges and the future of BVS development are discussed in detail as the best available approach for vascular restoration therapy.The criteria of materials selection,design and processing principles of BVS,and the corresponding clinical trial results are also summarized in this article.展开更多
Objective To update the current status of bioresorbable scaffold, highlights the potential future prospective of innovative bioresorbable scaffold technology.Data sources Data were obtained from papers published in Pu...Objective To update the current status of bioresorbable scaffold, highlights the potential future prospective of innovative bioresorbable scaffold technology.Data sources Data were obtained from papers published in PubMed, presentations from the following conferences: EuroPCR, Transcatheter Cardiovascular Therapeutics, and Chinese Interventional Therapeutics.Results Bioresorbable scaffold has been introduced as a potential workhorse device for the treatment of coronary artery disease, with providing temporary vessel scaffold, then gradually being resorbed free of any caging, eventually restoring the vessel wall physiology and vasomotion. The clinical outcomes regarding the safety and efficacy following bioresorbable scaffolds implantation appear promising in the treatment of patients with either de novo lesions or acute myocardial infarction(AMI). In addition, two bioresorbable scaffolds currently investigated in Chinese population as well as several other bioresorbable scaffolds from Chinese manufactories are under development and preclinical evaluations.Conclusions Bioresorbable scaffolds with potential unique advantages have been rapidly developed and the initial clinical results are promising. Further preclinical and clinical evaluations are necessary to investigate their safety and efficacy in the treatment of Chinese patients with coronary artery disease.展开更多
Detection of in vivo biodegradation is critical for development of next-generation medical devices such as bioresorbable stents or scaffolds(BRSs).In particular,it is urgent to establish a nondestructive approach to e...Detection of in vivo biodegradation is critical for development of next-generation medical devices such as bioresorbable stents or scaffolds(BRSs).In particular,it is urgent to establish a nondestructive approach to examine in vivo degradation of a new-generation coronary stent for interventional treatment based on mammal experiments;otherwise it is not available to semi-quantitatively monitor biodegradation in any clinical trial.Herein,we put forward a semi-quantitative approach to measure degradation of a sirolimus-eluting iron bioresorbable scaffold(IBS)based on optical coherence tomography(OCT)images;this approach was confirmed to be consistent with the present weight-loss measurements,which is,however,a destructive approach.The IBS was fabricated by a metal-polymer composite technique with a polylactide coating on an iron stent.The efficacy as a coronary stent of this new bioresorbable scaffold was compared with that of a permanent metal stent with the name of trade mark Xience,which has been widely used in clinic.The endothelial coverage on IBS was found to be greater than on Xience after implantation in a rabbit model;and our well-designed ultrathin stent exhibited less individual variation.We further examined degradation of the IBSs in both minipig coronary artery and rabbit abdominal aorta models.The present result indicated much faster iron degradation of IBS in the rabbit model than in the porcine model.The semi-quantitative approach to detect biodegradation of IBS and the finding of the species difference might be stimulating for fundamental investigation of biodegradable implants and clinical translation of the next-generation coronary stents.展开更多
Fully bioresorbable scaffolds have been designed to overcome the limitations of traditional drug-eluting stents(DESs),which permanently cage the native vessel wall and pose possible complications.The ultrathin-strut d...Fully bioresorbable scaffolds have been designed to overcome the limitations of traditional drug-eluting stents(DESs),which permanently cage the native vessel wall and pose possible complications.The ultrathin-strut designed sirolimus-eluting iron bioresorbable coronary scaffold system(IBS)shows comparable mechanical properties to traditional DESs and exhibits an adaptive degradation profile during target vessel healing,which makes it a promising candidate in all-comers patient population.For implanted medical devices,magnetic resonance(MR)imaging properties,including MR safety and compatibility,should be evaluated before its clinical use,especially for devices with intrinsic ferromagnetism.In this study,MR safety and compatibility of the IBS scaffold were evaluated based on a series of well-designed in-vitro,ex-vivo and in-vivo experiments,considering possible risks,including scaffold movement,over-heating,image artifact,and possible vessel injury,under typical MR condition.Traditional ASTM standards for MR safety and compatibility evaluation of intravascular devices were referred,but not only limited to that.The unique time-relevant MR properties of bioresorbable scaffolds were also discussed.Possible forces imposed on the scaffold during MR scanning and MR image artifacts gradually decreased along with scaffold degradation/absorption.Rigorous experiments designed based on a scientifically based rationale revealed that the IBS scaffold is MR conditional,though not MR compatible before complete absorption.The methodology used in the present study can give insight into the MR evaluation of magnetic scaffolds(bioresorbable)or stents(permanent).展开更多
In contrast to polymer bioresorbable stents(BRS)that exhibited suboptimal performance in clinical trials due to their deficient mechanical properties,metallic BRS with improved mechanical strength have made their way ...In contrast to polymer bioresorbable stents(BRS)that exhibited suboptimal performance in clinical trials due to their deficient mechanical properties,metallic BRS with improved mechanical strength have made their way into the clinic and have demonstrated more promising results.In the roadmap of research and development of metallic BRS,magnesium and iron based biodegradable metal stents had been clinically used,and the zinc based biodegradable metal stents had been trailed in Mini-Pigs.In this mini-review paper,we demonstrate the current technology levels and point out the future R&D direction of metallic BRS.Magnesium based BRS should target for decreasing struct thickness meanwhile balancing with enough supporting strength.Iron based BRS should move towards high efficient absorption,conversion,metabolism,elimination of its degradation products.Zn based BRS should strive to improve mechanical stability,creep resistance and biocompatibility.Future R&D directions of metallic BRS should move towards new materials such as Molybdenum,intelligent stent integrated with degradable biosensors,and new stent with multiple biofunctions,such as NO release.展开更多
文摘BACKGROUND Bioresorbable scaffolds(BRS)are a promising alternative to traditional drugeluting stents(DES)for the treatment of acute coronary syndrome(ACS).They offer the potential for complete resorption,which may reduce long-term complications such as stent thrombosis and late restenosis.However,the safety,compatibility,and long-term outcomes of BRS in patients with intermediate to low-risk ACS have yet to be thoroughly investigated.AIM To investigate the safety,compatibility,and long-term outcomes of BRS in patients with intermediate to low-risk ACS.METHODS Patients with intermediate to low-risk ACS who underwent percutaneous coronary intervention with either DES or BRS,and were continuously recruited from January 2019 to June 2022 at a single center,were analyzed.Baseline data and clinical follow-up were collected for patients who underwent DES implantation(control group)and BRS implantation(observation group),and the survival outcomes and complications during a maximum follow-up period of 3 years were compared.The primary clinical endpoint was device-oriented composite endpoint(DoCE),representing the occurrence of one of the following events:Cardiac death,stent thrombosis,target vessel myocardial infarction,and clinically driven target lesion revascularization.Secondary endpoints included coronary artery bypass grafting,target vessel revascularization,and non-cardiac death.RESULTS A total of 128 patients were included in this study,with an average age of 63 years.Among them,95 were male(74%).The study involved treatment of 201 blood vessels:87(43%)received BRS,and 114(57%)received DES.A total of 97 patients completed the full 3-year follow-up.During this period,5 patients(17%)in the observation group and 7 patients(16%)in the control group experienced a major cardiovascular event(DoCE).At the 1-year follow-up,7 patients(15%)in the observation group and 6 patients(10%)in the control group experienced DoCE,and this difference was statistically significant(P<0.05).At the 2-year follow-up,there was also a significant difference between the two groups in the number of patients who needed repeat treatment of the target blood vessel(P<0.05).In the observation group,18 patients(33%)underwent follow-up coronary angiography.During the follow-up period,one patient in the observation group was found to have re-narrowing in the proximal and middle segments of the left anterior descending artery,possibly due to BRS collapse.Another patient in the observation group developed chronic total occlusion in multiple vessels at the 3-year follow-up and underwent coronary artery bypass grafting.CONCLUSION In low-to intermediate-risk ACS patients,those who got BRS had their first major heart event sooner than those who got DES.BRS is more tissue-friendly,yet over three years both groups had about the same amount of problems-only a few BRS patients still saw the scaffold collapse or the vessel slowly block.
基金Supported by Health Commission of Hunan Province,No.202203014389Chinese Medicine Research Project of Hunan Province,No.A2023051the Natural Science Foundation of Hunan Province,No.2024JJ9414.
文摘BACKGROUND With the development of percutaneous coronary intervention(PCI),the number of interventional procedures without implantation,such as bioresorbable stents(BRS)and drug-coated balloons,has increased annually.Metal drug-eluting stent unloading is one of the most common clinical complications.Comparatively,BRS detachment is more concealed and harmful,but has yet to be reported in clinical research.In this study,we report a case of BRS unloading and successful rescue.This is a case of a 59-year-old male with the following medical history:“Type 2 diabetes mellitus”for 2 years,maintained with metformin extended-release tablets,1 g PO BID;“hypertension”for 20 years,with long-term use of metoprolol sustained-release tablets,47.5 mg PO QD;“hyperlipidemia”for 20 years,without regular medication.He was admitted to the emergency department of our hospital due to intermittent chest pain lasting 18 hours,on February 20,2022 at 15:35.Electrocardiogram results showed sinus rhythm,ST-segment elevation in leads I and avL,and poor R-wave progression in leads V1–3.High-sensitivity troponin I level was 4.59 ng/mL,indicating an acute high lateral wall myocardial infarction.The patient’s family requested treatment with BRS,without implanta-tion.During PCI,the BRS became unloaded but was successfully rescued.The patient was followed up for 2 years;he had no episodes of angina pectoris and was in generally good condition.CONCLUSION We describe a case of a 59-year-old male experienced BRS unloading and successful rescue.By analyzing images,the causes of BRS unloading and the treatment plan are discussed to provide insights for BRS release operations.We discuss preventive measures for BRS unloading.
文摘The evolution of coronary intervention techniques and equipment has led to more sophisticated procedures for the treatment of highly complex lesions.However,as a result,the risk of complications has increased,which are mostly iatrogenic and often include equipment failure.Stent dislodgement warrants vigilance for the early diagnosis and a stepwise management approach is required to either expand or retrieve the lost stent.In the era of bioresorbable scaffolds that are not radiopaque,increased caution is required.Intravascular imaging may assist in detecting the lost scaffold in cases of no visibility fluoroscopically.Adequate lesion preparation is the key to minimizing the possibility of equipment loss;however,in the case that it occurs,commercially available and improvised devices and techniques may be applied.
文摘In this letter,we comment on a recent case report by Sun et al in the World Journal of Cardiology.The report describes the successful management of a rare complication:The unloading or detachment of a bioresorbable stent(BRS)during percutaneous coronary intervention(PCI)in a male patient.The unloading of BRS was detected via angiography and intravascular ultrasound(IVUS)imaging of the left coronary artery and left anterior descending artery.Although this case is interesting,the authors’report lacked crucial details.Specifically,insufficient information about the type of BRS used,potential causes of BRS unloading,or whether optical coherence tomography(OCT)imaging for coronary arteries was performed before,during,or after PCI.The OCT imaging of coronary arteries before PCI can potentially prevent BRS unloading due to its higher resolution compared to IVUS.In addition,despite detecting myocardial bridging during the PCI,the authors did not provide any details regarding this variation.Here we discuss the various types of BRS,the importance of OCT in PCI,and the clinical relevance of myocardial bridging.
基金This project was supported by the National Scientific Committee(969202011), the Natural Science Foundation of Hubei Province(99J
文摘Aim. To investigate the bioactivity of the self- designed biodegradable osteosynthetic devices made of resorbable hydroxyapatite microparticles/ poly- DL- lactide (HA/PDLLA) composites. Method. Forty- three rabbits with a transverse transcondylar osteotomy of the distal femur were fixed intramedullary by a HA/PDLLA rod, the duration of follow- up were 3， 6， 12, 24 and 36 weeks. Histological, scanning electron microscopic (SEM), energy dispersive X- ray (EDX) and biomechanical analyses were done. Results. Active new bone formation and direct bone- bonding were seen at the bone- implant interface. Generous apatite crystals deposited and grew on the surface of the composites at 3～ 6 weeks postoperation. The interfacial shear strength increased significantly. Conclusion. Through the incorporating of resorbable HA microparticles, specific bone- bonding and active osteogenic capacity is introduced. This kind of bioactivity, together with other properties such as sufficient mechanical strength, enhanced biocompatibility and radiopacity, which are intrinsically unobtainable in totally resorbable polymer/polymer systems, make the HA/PDLLA composites become a desirable material for the internal fixation of cancellous bone.
文摘BACKGROUND The in-stent restenosis(ISR)rates are reportedly inconsistent despite the increased use of second-generation drug eluting stent(DES).Although bioresorbable vascular scaffold(BVS)have substantial advantages with respect to vascular restoration,the rate of scaffold thrombosis is higher with BVS than with DES.Optimal treatment strategies have not been established for DES-ISR to date.CASE SUMMARY We report on a case of a 60-year-old man patient with acute coronary syndrome.He had a history of ST-segment elevation myocardial infarction associated with very late scaffold thrombosis and treated with a DES.Coronary angiography revealed significant stenosis,suggesting DES-ISR on the previous BVS.Optical coherence tomography(OCT)identified a plaque rupture and a disrupted scaffold strut in the neointimal proliferation of DES.To treat the DES-ISR on the previous BVS,we opted for a drug-coated balloon(DCB)after a balloon angioplasty using a semi-compliant and non-compliant balloon.The patient did not experience adverse cardiovascular events on using a DCB following the use of intensive dual antiplatelet therapy and statin for 24 mo.CONCLUSION This case highlights the importance of OCT as an imaging modality for characterizing the mechanism of target lesion failure.The use of a DCB following the administration of optimal pharmacologic therapy may be an optimal strategy for the treatment and prevention of recurrent BVS thrombosis and DES-ISR.
文摘Background Current studies,including randomized trials and meta-analyses evaluating clinical Results of bioresorbable scaffold(BRS),have raised concerns about the first-generation device with thicker struts and limited expansion capability.Newer BRS with thinner struts and improved deliverability are expected to enhance safety and efficacy profile.Bioheart(Bio-Heart,Shanghai,China)BRS is constructed from a PLLA backbone coated with a PDLLA layer eluting sirolimus.Sixmonth Results have proved preliminary safety and effectiveness of the Bioheart BRS in patients with single de novo coronary artery lesions.We sought to report serial intracoronary imaging findings at 1 year.
文摘Background: There is a large assortment of modalities for the surgical treatment/management of distal radius fractures (DRFs), where the most widely used is the fixed-angle volar plating (VLP) system, which, sometimes, is referred to as the “surgical modality of choice”. While outcomes with each modality are usually good to excellent, each has its share of shortcomings and complications. Thus, there is scope for improvements to existing modalities and/or introduction of new ones. Study Purpose: We introduce a novel modality, namely, the prototype of an intramedullary injectable bioresorbable polymer-bioresorbable balloon osteosynthesis (IPBO) system, and investigated its plausibility. Experimental Procedures: The biomechanical performance of a construct comprising a synthetic distal radius (fourth-generation Sawbones?) on which a simulated fracture was created (4-mm wide osteotomy positioned 25 mm from the most distal end of the radius) and fixated with a placement of the IPBO system (SIPBO Construct) was compared to that when the fixation was with an approved Ti-6Al-4V alloy VLP system (SVLP Construct), under a clinically-relevant compressive loading protocol. Performance involved determination of quantitative parameters of the construct (initial longitudinal stiffness (ICLS), final longitudinal stiffness (FCLS), and load-to-failure (Pf)) and observation and recording of features of the construct at the fracture point. We also determined the quantitative parameters for the intact synthetic distal radius (control). Results: For each of the quantitative parameters, the range of values for SIPBO Construct was within that for SVLP Construct, suggesting that the IPBO System is a plausible modality. Also, for SIPBO Construct, failure occurred within the polymer zone, whereas, for SVLP Construct, some failure features were fracture of the cortical wall and of the dorsal proximal fragments. Conclusion: The findings suggest that the IPBO system is plausible. As such, it merits further study;for example, determination of the influence of fracture gap fill ratio (defined as the proportion of the fracture gap that is filled by the expanding balloon as the polymer is injected into the balloon) on a large collection of quantitative biomechanical parameters.
文摘The most popular treatment/management modality for coronary artery disease, which is one of the leading causes of death, is percutaneous transluminal coronary intervention (popularly known as “plain old balloon angioplasty”) followed by implantation of a stent (“stenting”). Stent types have evolved from bare metal stents through first-generation drug-eluting stents to fully bioresorbable stents (FBRSs). Two examples of FBRSs are 1) Mg scaffold with no coating;and 2) Mg alloy scaffold coated with a bioresorbable polymer in which an anti-proliferative drug is embedded. In the case of Mg/Mg alloy FBRSs, one of the reported clinical results is that the resorption time of the stent is too short (in vivo resorption time (and, hence, improving the clinical efficacy) of the current generation of fully-bioresorbable Mg/Mg-alloy stents as well as guide the development of the next generation of these stents.
文摘We describe the case of a patient presenting with STsegment elevation myocardial infarction due to very late scaffold thrombosis. The patient was already admitted for an elective percutaneous recanalization of a chronically occluded left anterior descending artery(LAD). The procedure was performed according the subintimal tracking and re-entry(STAR) technique with 4 bioresorbable vascular scaffolds implantation. However, even though the coronary flow was preserved at the end of the procedure, the dissected segment was only partially sealed at the distal segment of the LAD. After 18 mo of regular assumption, dual antiplatelet therapy was discontinued for 10 mo before his presentation at the emergency room. This is the first reported case of a very late scaffold thrombosis after coronary chronic total occlusion(CTO) recanalization performed according to the STAR technique. This case raises concerns about the risk of very late scaffold thrombosis after complex CTO revascularization.
文摘Objectives: This study explores feasibility of tissue-engineered osteogenesis using sterile coral implants loaded with homologous osteoblasts to repair bone defects. Study Design: A unilateral 4 mm transverse dis- continuity defect was produced approximately mid-way along left radius of young female rabbits using ro- tary diamond disc under continuous saline irrigation and stabilised with autoclaved steel miniplate and screws. The defect was then fitted with sterile bioresorbable coral implant loaded with homologous neonatal calvarial osteoblasts or control implants without osteoblasts. All animals underwent radiography immedi- ately post-operative, at weekly intervals for four weeks and at fortnightly intervals thereafter. Operated bones were histologically evaluated for osteogenesis at 12 weeks. Results: Findings demonstrate osteogenesis and complete repair of bioresorbable coral implant by homologous osteoblasts loaded on coral scaffold. Conclu- sions: Single stage surgery using this technique to induce osteogenesis and closure of discontinuity bone de- fects including palatal clefts and peripheral reduction of large craniofacial defects might prove better thera- peutic modality than autologous bone grafting or tissue distraction osteogenesis.
文摘Purpose: To report a novel technique of laparoscopic 10 mm Single Port Access IntraPeritoneal Onlay Mesh (SPA-IPOM) using bioresorbable composite mesh fixed with Endoclose suture (percutaneous subcutaneous suture) in 3 cases of bilateral inguinal hernia. Methods: Laparoscopic SPA-IPOM is done through a 10 mm trocar with one 10 mm instrument that has 5 mm optical lens and 5 mm channel for grasper. After inserting 10 mm trocar at umbilicus using semi-open technique, intraperitoneal anatomical landmark of inguinal her-nia is identified. A 10 × 15 cm pre-tied bioresorbable composite mesh is then placed to cover hernia defect and all three potential area of indirect, direct and femoral hernia. Using Endoclose? needle, each pair of pre-tied sutures is retrieved percutaneously through a needle wound and extracorporeal tied with knot in subcutaneous space. After the upper half of mesh is sutured to the posterior surface of abdominal wall, the lower half of mesh is fixed by hernia tacker to Symphysis Pubis, Cooper Ligament and Iliopubic tract. Re-sults: Three men, average 48 year olds were operated by laparoscopic 10 mm SPA-IPOM for bilateral in-guinal hernia repair using bioresorbable composite mesh. Average operative time was 36 minutes. No imme-diate complication. All patients were discharge on the 2nd post-operative day and average 6 months follow up has no recurrence. Conclusions: Laparoscopic SPA-IPOM is an optional operation and is much easier to be performed. Benefits include operative time saving, cosmesis, early discharge and early return to work. Bio-resorbable composite mesh prevents bowel adhesion, however, is much more expensive. Long term follow up study for complications and recurrence is needed.
基金supported by National Key R&D Program of China(grant number 2018YFC1106600)Shenzhen Industrial and Information Technology Bureau(20180309174916657)+1 种基金Science,Technology and Innovation Commission of Shenzhen Municipality(grant number GJHZ20180418190517302)Natural Science Foundation of China(grant number 52101282).
文摘Iron is considered as an attractive alternative material for bioresorbable scaffolds(BRS).The sirolimus eluting iron bioresorbable scaffold(IBS),developed by Biotyx Medical(Shenzhen,China),is the only iron-based BRS with an ultrathin-wall design.The study aims to investigate the long-term efficacy,safety,biocompatibility,and lumen changes during the biodegradation process of the IBS in a porcine model.A total of 90 IBSs and 70 cobaltchromium everolimus eluting stents(EES)were randomly implanted into nonatherosclerotic coronary artery of healthy mini swine.The multimodality assessments including coronary angiography,optical coherence tomography,micro-computed tomography,magnetic resonance imaging,real-time polymerase chain reaction(PCR),and histopathological evaluations,were performed at different time points.There was no statistical difference in area stenosis between IBS group and EES group at 6 months,1year,2 years and 5 years.Although the scaffolded vessels narrowed at 9 months,expansive remodeling with increased mean lumen area was found at 3 and 5 years.The IBS struts remained intact at 6 months,and the corrosion was detectable at 9 months.At 5 years,the iron struts were completely degraded and absorbed in situ,without in-scaffold restenosis or thrombosis,lumen collapse,aneurysm formation,and chronic inflammation.No local or systemic toxicity and abnormal histopathologic manifestation were found in all experiments.Results from real-time PCR indicated that no sign of iron overload was reported in scaffolded segments.Therefore,the IBS shows comparable efficacy,safety,and biocompatibility with EES,and late lumen enlargement is considered as a unique feature in the IBS-implanted vessels.
基金supported by the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX230191).
文摘As the world's population ages,peripheral vascular disease(PVD)has become one of the leading causes of death,caused by atherosclerosis and vascular stenosis.PVD typically affects the lower extremities,placing a significant financial burden on both individuals and healthcare systems worldwide.Open bypass surgery has traditionally been the most common treatment for PVD,but the procedure carries a high rate of perioperative adverse events.
基金This study was supported by National Key R&D Program of China(grants number 2018YFC1106600)Shenzhen Industrial and Information Technology Bureau(20180309174916657)Science,Technology and Innova-tion Commission of Shenzhen Municipality(grant number GJHZ20180418190517302).
文摘This study aimed to investigate the long-term biocompatibility, safety, and degradation of the ultrathin nitrided iron bioresorbable scaffold (BRS) in vivo, encompassing the whole process of bioresorption in porcine coronary arteries. Fifty-two nitrided iron scaffolds (strut thickness of 70 μm) and 28 Vision Co–Cr stents were randomly implanted into coronary arteries of healthy mini-swine. The efficacy and safety of the nitrided iron scaffold were comparable with those of the Vision stentwithin 52 weeks after implantation. In addition, the long-term biocompatibility, safety, and bioresorption of the nitrided iron scaffold were evaluated by coronary angiog-raphy, optical coherence tomography, micro-computed tomography, scanning electron microscopy, energy dispersive spectrometry and histopathological evaluations at 4, 12, 26, 52 weeks and even at 7 years after im-plantation. In particular, a large number of struts were almost completely absorbed in situ at 7 years follow-up, which were first illustrated in this study. The lymphatic drainage pathway might serve as the potential clearance way of iron and its corrosion products.
文摘This article describes the evolution of minimally invasive intervention technologies for vascular restoration therapy from early-stage balloon angioplasty in 1970s,metallic bare metal stent and metallic drug-eluting stent technologies in 1990s and 2000s,to bioresorbable vascular scaffold(BVS)technology in large-scale development in recent years.The history,the current stage,the challenges and the future of BVS development are discussed in detail as the best available approach for vascular restoration therapy.The criteria of materials selection,design and processing principles of BVS,and the corresponding clinical trial results are also summarized in this article.
文摘Objective To update the current status of bioresorbable scaffold, highlights the potential future prospective of innovative bioresorbable scaffold technology.Data sources Data were obtained from papers published in PubMed, presentations from the following conferences: EuroPCR, Transcatheter Cardiovascular Therapeutics, and Chinese Interventional Therapeutics.Results Bioresorbable scaffold has been introduced as a potential workhorse device for the treatment of coronary artery disease, with providing temporary vessel scaffold, then gradually being resorbed free of any caging, eventually restoring the vessel wall physiology and vasomotion. The clinical outcomes regarding the safety and efficacy following bioresorbable scaffolds implantation appear promising in the treatment of patients with either de novo lesions or acute myocardial infarction(AMI). In addition, two bioresorbable scaffolds currently investigated in Chinese population as well as several other bioresorbable scaffolds from Chinese manufactories are under development and preclinical evaluations.Conclusions Bioresorbable scaffolds with potential unique advantages have been rapidly developed and the initial clinical results are promising. Further preclinical and clinical evaluations are necessary to investigate their safety and efficacy in the treatment of Chinese patients with coronary artery disease.
基金National Key R&D Program of China(grants number 2018YFC1106600 and 2016YFC1100300)Shenzhen Industrial and Information Technology Bureau(20180309174916657)+1 种基金Science,Technology and Innovation Commission of Shenzhen Municipality(grant number GJHZ20180418190517302)The authors thank Dr.Renu Virmani for her expert assistance on endothelialization and histopathology analysis.
文摘Detection of in vivo biodegradation is critical for development of next-generation medical devices such as bioresorbable stents or scaffolds(BRSs).In particular,it is urgent to establish a nondestructive approach to examine in vivo degradation of a new-generation coronary stent for interventional treatment based on mammal experiments;otherwise it is not available to semi-quantitatively monitor biodegradation in any clinical trial.Herein,we put forward a semi-quantitative approach to measure degradation of a sirolimus-eluting iron bioresorbable scaffold(IBS)based on optical coherence tomography(OCT)images;this approach was confirmed to be consistent with the present weight-loss measurements,which is,however,a destructive approach.The IBS was fabricated by a metal-polymer composite technique with a polylactide coating on an iron stent.The efficacy as a coronary stent of this new bioresorbable scaffold was compared with that of a permanent metal stent with the name of trade mark Xience,which has been widely used in clinic.The endothelial coverage on IBS was found to be greater than on Xience after implantation in a rabbit model;and our well-designed ultrathin stent exhibited less individual variation.We further examined degradation of the IBSs in both minipig coronary artery and rabbit abdominal aorta models.The present result indicated much faster iron degradation of IBS in the rabbit model than in the porcine model.The semi-quantitative approach to detect biodegradation of IBS and the finding of the species difference might be stimulating for fundamental investigation of biodegradable implants and clinical translation of the next-generation coronary stents.
基金supported by the National Key Research and Development Program of China(No.2018YFC1106600)the International Cooperation Research Project of Shenzhen No.GJHZ20180418190517302.
文摘Fully bioresorbable scaffolds have been designed to overcome the limitations of traditional drug-eluting stents(DESs),which permanently cage the native vessel wall and pose possible complications.The ultrathin-strut designed sirolimus-eluting iron bioresorbable coronary scaffold system(IBS)shows comparable mechanical properties to traditional DESs and exhibits an adaptive degradation profile during target vessel healing,which makes it a promising candidate in all-comers patient population.For implanted medical devices,magnetic resonance(MR)imaging properties,including MR safety and compatibility,should be evaluated before its clinical use,especially for devices with intrinsic ferromagnetism.In this study,MR safety and compatibility of the IBS scaffold were evaluated based on a series of well-designed in-vitro,ex-vivo and in-vivo experiments,considering possible risks,including scaffold movement,over-heating,image artifact,and possible vessel injury,under typical MR condition.Traditional ASTM standards for MR safety and compatibility evaluation of intravascular devices were referred,but not only limited to that.The unique time-relevant MR properties of bioresorbable scaffolds were also discussed.Possible forces imposed on the scaffold during MR scanning and MR image artifacts gradually decreased along with scaffold degradation/absorption.Rigorous experiments designed based on a scientifically based rationale revealed that the IBS scaffold is MR conditional,though not MR compatible before complete absorption.The methodology used in the present study can give insight into the MR evaluation of magnetic scaffolds(bioresorbable)or stents(permanent).
基金supported by Longhua District Project(2022035)National Natural Science Foundation of China(Grant No.51931001 and U22A20121)+1 种基金Fund for International Cooperation and Exchange between NSFC(China)and CNR(Italy)(NSFC-CNR Grant No.52011530392)Fund for International Cooperation and Exchange between NSFC(China)and RFBR(Russia)(NSFC-RFBR Grant No.52111530042).
文摘In contrast to polymer bioresorbable stents(BRS)that exhibited suboptimal performance in clinical trials due to their deficient mechanical properties,metallic BRS with improved mechanical strength have made their way into the clinic and have demonstrated more promising results.In the roadmap of research and development of metallic BRS,magnesium and iron based biodegradable metal stents had been clinically used,and the zinc based biodegradable metal stents had been trailed in Mini-Pigs.In this mini-review paper,we demonstrate the current technology levels and point out the future R&D direction of metallic BRS.Magnesium based BRS should target for decreasing struct thickness meanwhile balancing with enough supporting strength.Iron based BRS should move towards high efficient absorption,conversion,metabolism,elimination of its degradation products.Zn based BRS should strive to improve mechanical stability,creep resistance and biocompatibility.Future R&D directions of metallic BRS should move towards new materials such as Molybdenum,intelligent stent integrated with degradable biosensors,and new stent with multiple biofunctions,such as NO release.
