Bioresorbable Scaffold Research Articles

Past and Recent Progress on Metallic Digestive Tract Stents.

The implantation of digestive tract stents at various lesion sites can effectively improve digestive tract patency, opening up an excellent treatment method for diseases that are currently incurable or resistant to conventional surgery. Digestive tract stents have been extensively studied and widely used worldwide due to their unique advantages of simple implantation, low trauma, satisfactory effect, and low complication rate. Among the various types of stents, metallic stents have been developed to improve surgical efficacy due to their excellent mechanical properties and are constantly being improved. This review provides an overview of the design and development of conventional nonbiodegradable metallic digestive tract stents such as nitinol (NiTi alloy), stainless steel, and cobalt-based alloy stents. Furthermore, biodegradable metallic stents for the digestive tract, such as magnesium-based, iron-based, and zinc-based stents, are described. This paper also evaluates the advantages and disadvantages of existing metallic digestive stents as well as future research directions and challenges in the development of metallic digestive tract stents.

A novel stent flow chamber system demonstrates reduced thrombogenicity of bioresorbable magnesium scaffolds

Coronary artery disease (CAD) is characterized by narrowing and subsequent blockade of coronary arteries, and imposes a significant health and economic burden. Stent and scaffold devices are introduced in advanced CAD to improve vascular stability and restore blood flow. Although in vitro flow systems like the Chandler loop have been developed to enhance the understanding of interactions between device materials, their coatings, and vascular cells, imaging-based in vitro analysis of device performance is limited. In this study, we established a novel stent flow chamber system designed to assess the thrombogenicity of bioresorbable magnesium scaffold (RMS) and stent materials in vitro. Additionally, we compared the thrombogenicity – an important clinical parameter in stent performance – of the Magmaris-316 L stainless steel stent with its predecessors, Magmaris RMS and a prototype of the third-generation RMS (DREAMS 3G). Analysis of platelet adhesion and coverage of the different devices under flow conditions demonstrated that the Magmaris RMS exhibits reduced thrombogenicity compared to the Magmaris-316 L stainless steel stent. Moreover, thrombogenicity of the DREAMS 3G prototype, composed of BIOmag material, is further decreased compared to its predecessors. The observed reduction in thrombogenicity of the DREAMS 3G prototype in vitro suggests additional improvements in clinical safety and efficacy, highlighting its promise for treating CAD. Future research on this prototype may thus open avenues for analyzing other blood components and patient-derived endothelial cells. In line with the 3R principles, this approach may also help reduce the need for animal testing.

High-Risk Biliary Anastomosis During Robotic Pancreaticoduodenectomy: Initial Experience with Biodegradable Biliary Stent

Background and Objectives: Biliary fistulas (BFs) occur in approximately 3–8% of patients undergoing pancreaticoduodenectomy (PD), and the bile duct diameter ≤ 5 mm is the most important risk factor. The aim of this study was to evaluate the efficacy of biodegradable biliary stents (BSs) in reducing complications in patients undergoing robotic pancreaticoduodenectomy (RPD) with a bile duct diameter of ≤5 mm. Materials and Methods: A retrospective single-centre observational study was conducted. Patients undergoing RPD after the completion of the robotic biliary anastomosis learning curve were included in this study. Only patients with a bile duct diameter ≤ 5 mm were included in the analysis. A prospectively held database was used. The intraoperative time for biliary anastomosis was extracted from surgical videos. Results: Of 30 patients, 20 received no biliary stent (nBS) and 10 received a biodegradable stent (BS). The decision to use a stent was based on product availability. The median operative time for biliary anastomosis was significantly shorter in the BS group compared to the nBS group, at 15 min versus 24 min (p < 0.001). Three patients in the nBS group developed a BF, whereas none were observed in the BS group. No stent migration was observed in any of the patients. Conclusions: The use of biodegradable biliary stents in high-risk biliary anastomosis in RPD appears to effectively reduce the incidence of BFs and may serve as a viable strategy to mitigate early biliary complications. The use of biodegradable stents facilitates a faster and easier biliary anastomosis. These findings suggest a potential benefit of using biodegradable stents in complex biliary reconstruction. However, larger studies are needed to confirm these results.

Five-year clinical outcomes of STEMI patients treated with a pre-specified bioresorbable vascular scaffold implantation technique: Final results of the BVS STEMI STRATEGY-IT

BackgroundData on Absorb bioresorbable vascular scaffold (BVS) use in patients presenting with ST-segment elevation myocardial infarction (STEMI) are limited. Furthermore, Absorb studies including STEMI patients lacked a prespecified implantation technique to optimize BVS deployment. This study examines the 5-year outcomes of BVS in STEMI patients using an optimized implantation strategy and the impact of prolonged dual antiplatelet therapy (DAPT). MethodsThe BVS STEMI STRATEGY-IT study is a prospective, non-randomized, single-arm multicenter trial (NCT02601781). It involved 505 STEMI patients undergoing primary percutaneous coronary intervention with a predefined BVS implantation protocol. Key endpoints were a 5-year device-oriented composite endpoint (DOCE) of cardiac death, target-vessel myocardial infarction (TV-MI), and ischemia-driven target lesion revascularization (ID-TLR). The study also compared outcomes based on DAPT duration (36 months vs. shorter). Results502 (99.4 %) patients completed the 5-year follow-up. DOCE rate was 2.4 %. ID-TLR, TV-MI, and cardiac death rates were 1.6 %, 0.8 %, and 0.6 %, respectively. No DOCE occurred between three and five years. Scaffold thrombosis (ScT) was 1 %, all occurring within 24 months. Longer-term DAPT significantly reduced DOCE (1.3 % vs. 4.3 %; HR: 0.29; 95 % CI: 0.1–0.9; p = 0.03) driven by a lower rate of TV-MI (0 % vs. 2.2 %; p = 0.018) compared to shorter-term DAPT, as well as ScT (0 % vs 2.7 %, p = 0.007). ConclusionsThis study shows favorable 5-year outcomes for BVS in selected STEMI patients with an optimized implantation strategy. Prolonged DAPT further improved outcomes, emphasizing its role in reducing adverse events during scaffold resorption. Further research is needed to assess newer-generation bioresorbable devices.

Surgical Technique: Using an Acellular Dermal Allograft and Bioresorbable Wick Scaffold During Endoscopic Gluteus Medius and Minimus Repair

Lateral hip pain, also known as greater trochanteric pain syndrome, encompasses a spectrum of pathology, including trochanteric bursitis, gluteus medius and minimus tears, and iliotibial band pathology. Patients with greater trochanteric pain syndrome can have tearing of the hip abductors, leading to refractory pain that may necessitate surgical repair. Compared to an open approach, endoscopic gluteus tendon repair is becoming more popular and has been shown to decrease morbidity. Similar to rotator cuff repairs, hip abductor repairs are subject to failure secondary to many factors. These include poor biology, tear size, tissue quality, and deficiency of tendon-to-bone healing. Previous work included the use of acellular dermal allograft to augment at-risk gluteus medius and minimus repairs and improve repair strength. The following technique utilizes a rotium bioresorbable wick scaffold at the bone-tendon interface in addition to an acellular dermal allograft covering the repair in a “biological sandwich” to further augment repair. This technique focuses on the addition of rotium augment implementation and fixation in a safe and reproducible manner.

Investigation of the Degradation Behaviour of Poly-L-Lactic Acid Braided Stents Under Real-Time and Accelerated Conditions

Degradation tests are a key step in the development of a bioresorbable stent. The present study focused on the degradation of bioresorbable stents made from PLLA filaments, and examined the variation of the physical, thermal, and mechanical properties of the material and the devices under both real-time and accelerated degradation conditions. Results showed that the undegraded filaments were highly crystalline and composed by both and crystalline phases, induced by both the melt spinning and heat treatment processes. The latter was shown to have an important influence on the further formation of crystalline phase and therefore crystalline structure perfectioning. Real-time degradation tests showed that the devices maintained structural stability for up to a year, meeting the required 6-month degradation period for vascular stents. Degradation was shown to primarily affect the crystalline regions, and to cause a gradual loss of material ductility before any mass loss or decrease in crystallinity. In turn, a constant decrease of molecular weight was observed, with stent failure occurring around day 389 due to a drop in molecular weight below 10,000 g/mol. Accelerated degradation tests mirrored real-time results until mass loss began. Subsequently a slower molecular weight decrease was observed, with an increase and subsequent decrease of material crystallinity. The consistency of the data obtained between real-time and accelerated degradation before mass loss confirmed the possibility to gain insights into real-time degradation through an accelerated protocol. However, attention must be paid to the initial molecular weight of the material, which has been shown to highly influence the acceleration rate. This study provides a wide range of experimental data both on the real-time and thermally accelerated degradation behaviour of PLLA braided stents that can be used as benchmark for further studies in the field.

Evaluation of Post-Processing on Additive Manufactured Bioresorbable Polymers for Medical Devices.

Additive manufacturing (AM) has seen massive growth in the medical device sector and an increase in the clearance of devices. Many challenges still exist in the design, development, and clinical use of AM-fabricated devices, notably the processing, annealing, and sterilization of resorbable polymers. In addition, the use of these materials continues to grow in medical devices and scaffold technologies for tissue engineering and regenerative medicine (TERM). Specifically, this study focused on the scaffold mechanical properties post-processing and throughout a simulated resorption (in vitro) study. Herein, we evaluated three (3) materials that span a range of mechanical properties and degradation rates relating to a range of tissue healing rates and mechanical properties affording the opportunity of biomimetic potentials, Caproprene 100M, Lactoflex 7415, and Lactoprene 100M. These bioresorbable polymers were additively manufactured into scaffold forms of Type V tensile bars to investigate post-processing parameters. A range of heat treatments were then performed after the AM process to induce a range of semicrystalline morphologies, and subsequently, two different sterilization techniques were performed, one based on super critical carbon dioxide and another using electron beam radiation. It was statistically shown that the heat treatment parameters and the sterilization method had statistically significant effects on the scaffold properties of each material. While material differences were responsible for the majority of the mechanical property breadth, techniques utilizing analysis of variance allowed the observation of significant effects and interactions associated with heat treatment, sterilization, and material parameters (alpha = 0.05). The characterization of the sample groups provided insight into the process-structure-property-performance relationships of the resorbable scaffold samples. It was established that the post-processing impacted the scaffold structures, and therefore, sterilization and heat treatment selections should be included within initial design considerations alongside material selection as critical for device development, especially when AM bioresorbable scaffolds for TERM.

Assessment of Cutting-Balloon Angioplasty with Novel Bioabsorbable Polymer-Coated Everolimus-Eluting Stent in Treating Calcified Coronary Lesions Guided by Intravascular Ultrasound (CUPID Trial): study design and protocol

BackgroundVarious devices and techniques have been used for plaque modification in the treatment of severe coronary artery calcification. This prospective, multicenter, randomized, open-label study aims to evaluate the safety and efficacy of cutting balloon angioplasty using a novel bioabsorbable polymer-coated everolimus-eluting coronary stent for treating various degrees of calcified coronary lesions.MethodsWe outline the trial design aimed at assessing whether the cutting balloon (Wolverine™) is non-inferior to the non-compliant balloon in treating patients with calcified lesions, encompassing both de novo and in-stent restenosis (ISR) lesions. We aim to enroll 250 patients who have undergone bioabsorbable polymer-coated everolimus-eluting coronary stent (Synergy™) implantation. The primary endpoint is the minimal stent cross-sectional area at the calcium site as determined by intravascular ultrasonography. The secondary endpoints include major adverse cardiac events and target lesion revascularization at 12 months, alongside procedural convenience and operator-centric parameters, such as the number of balloons used, procedure time, and total contrast medium volume used.DiscussionIn this study, we will evaluate the efficacy and safety of Wolverine™ and non-compliant balloon in patients with calcified coronary lesions and provide a rationale for which type of balloons will optimally modify calcium lesions. In addition, we will attempt to expand the indications of the cutting balloon for treating mild-to-severe calcified coronary lesions. As the scope of insurance coverage for cutting balloons remains limited in some countries, this study may provide evidence for extending insurance coverage to the treatment of de novo calcified and ISR lesions.Trial registrationClinicalTrials.gov NCT06177808. Registered on January 1, 2024.

Cost-Effectiveness of Three Different New-Generation Drug-Eluting Stents in the Randomised BIO-RESORT Trial at 3 Years.

Evidence on health economic outcomes for percutaneous coronary intervention (PCI) comparing different contemporary drug-eluting stents (DES) with each other is scarce, as most previous randomised DES trials did not assess such aspects. This prespecified health economic evaluation of the Comparison of Biodegradable Polymer and Durable Polymer Drug-Eluting Stents in an All Comers Population (BIO-RESORT) trial aimed to compare at 3-year follow-up both health effects and costs of PCI with one of three new-generation drug-eluting stents (DES) in patients with obstructive coronary artery disease. The randomised BIO-RESORT trial assessed in 3514 patients the ultrathin-strut biodegradable polymer Orsiro sirolimus-eluting stent (SES) and very-thin-strut Synergy everolimus-eluting (EES) stent versus the thin-strut durable polymer Resolute Integrity zotarolimus-eluting stent (ZES). In the current analysis, we used the perspective of a health insurer in the Netherlands. The main endpoints were quality-adjusted life years (QALYs), and costs for each treatment strategy. Bootstrapping with 5000 resamples was performed to capture the uncertainty of results. Mean QALYs for each stent group were 2.566 for the SES, 2.551 for the EES, and 2.550 for the ZES. Mean costs per strategy were €14,670 for the SES, €14,946 for the EES, and €15,069 for the ZES. The SES had the highest probability of being cost-effective for every willingness-to-pay threshold up to €100,000 per QALY. Furthermore, in 79% of modelling scenarios, the SES was more effective and cheaper than ZES. At 3-year follow-up, PCI with the SES had the highest probability of being cost-effective due to greater effectiveness and lower costs compared with the ZES and EES. These findings suggest that, due to the overall high volume of coronary stenting in clinical practice, use of this SES could result in substantial cost savings, complemented by slight additional health benefits.

Bioresorbable stent unloading during percutaneous coronary intervention: Early detection and management

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.

Necessity sequential intermediate kissing balloon dilation for crush stenting: Further insights from metal/polymer vessel scaffolds bench testing.

Sequential intermediate kissing balloon dilation (sIKBD) is crucial for crush stenting, but it require appropriate procedure remains unclear for crush stenting. This study aims to investigate whether sIKBD is necessary and how it can be properly performed during crush stenting. Mini-crush stenting (mini-CS) and sIKBD for mini-crush stenting (sIKBD-mini-CS) using metal drug-eluting stents/polymer bioresorbable vessel scaffolds (mDES/pBVS) were emulated in bifurcation models considering the branch diameter difference, and sIKBD was added to mini-CS for pretreating side-branch (SB) stent before main-branch (MB) stenting (second figure), respectively. Micro-computed tomography was used to assess the morphological parameters of bifurcated stents including length of overlapping stent segment, residual ostial stenosis of the SB, and neocarina length using quantitative methods. Further, optical coherence tomography was to analyze the incidence of stent malapposition. Quantitative analysis demonstrated that in mDES/pBVS phantom, the neocarina length (mDES: 0.45 ± 0.10 mm vs 0.30 ± 0.09 mm, P = .005; pBVS: 0.47 ± 0.11 mm vs 0.29 ± 0.09 mm, P = .001), residual ostial stenosis at the SB (mDES: 19.37 ± 8.21% vs 12.47 ± 2.05%, P = .001; pBVS: 21.89 ± 8.54% vs 9.98 ± 3.35%, P = .035), and stent malapposition in the overlapping segment (mDES: 10.29 ± 3.31% vs 3.83 ± 0.97%, P = .001; pBVS: 12.05 ± 3.87% vs 6.40 ± 1.59%, P = .003) were lower in the sIKBD-mini-CS group than those in the mini-CS group (P < .05 for all). The results of factorial analysis showed that mDES platform tended to have better morphological indicators than the pBVS platform. Adding the sIKBD to mini-CS showed better morphologic characteristics of mDES/pBVS phantoms when compared with mini-CS. Therefore, it should be considered as a critical and proper technique for crush stenting.

A comparative invitro study of distinct and novel stent geometries on mechanical performances of poly-L-lactic acid cardiovascular stents.

Poly-L-lactic acid (PLLA) is one of the representative polymeric materials serving as bioresorbable stents (BRS) for cardiovascular disease due to its proper biodegradation, high biocompatibility, and adequate mechanical properties among polymer candidates for BRS. However, PLLA BRS as cardiovascular stents also have limitations because their mechanical properties including low radial strength and high elastic recoil are inferior to those of metallic-based BRS stents. In the study, we developed and manufactured distinct and novel types of stent geometries for investigating mechanical properties of thin-walled PLLA BRS (110 μm) for cardiovascular applications. Five key mechanical tests, including radial strength, crimping profile, flexibility, elastic recoil, and foreshortening were performed through a comprehensive analysis. In addition, we applied the finite element method for further validation and insight of mechanical behaviors of the PLLA BRS. Results revealed that Model 2 had advantages in high flexibility as well as radial strengths, which would be a proper option for complex and acutely curved lesions. Model 3 would be an optimum selection for stent placement in mild target site due to its strength in minimum elastic recoil. Even though Model 4 showed the highest radial strength, finite element simulation showed that the geometry caused higher maximum stress than that of Model 2 and Model 3 during the crimping process. Model 1 showed the most vulnerable geometry among the tested models in both invitro and finite element analysis. Such data may suggest potential guidance in regard to understanding the mechanical behaviors of PLLA BRS as not only applicable cardiovascular but also peripheral and intracranial stents.

First experience of implantation of a new-generation bioresorbable stent in a young patient with coronary artery disease: a case report

Implantation of a drug-eluting stent into the area of hemodynamically significant coronary artery lesion is a generally accepted and widespread method of coronary artery disease (CAD) treatment. However, rigid metallic frame in artery is associated with disrupted vascular biomechanics and neointimal proliferation in response to foreign material. These processes can lead to restenosis and/or late thrombosis of the implanted stent and, as a consequence, to the recurrence of CAD symptoms, as well as to adverse cardiovascular events. One of the options for solving the above problems is the implantation of bioresorbable stents. This technique already has an evidence base and is increasingly being introduced into routine clinical practice in certain groups of patients. The article presents a case of successful balloon angioplasty and stenting of the right coronary artery with a new-generation bioresorbable stent in a young patient with CAD.

A Snapshot on Clinical Trials on Zotarolimus DES: A Repurposing Drug against Myocardial Infarction

AbstractMyocardial infarction is the permanent death (necrosis) of heart muscle caused by a lack of oxygen for an extended period of time (ischemia). Since the very first percutaneous transluminal coronary angioplasty was done 40 years ago, the science of interventional cardiology has advanced dramatically. The above progression began with a balloon catheter attached to a fixed wire, advancing to bare-metal stents, first-generation drug-eluting stents (DES), second- and third-generation biodegradable polymer-based DES. Ultimately, bioabsorbable stents are still in development. Zotarolimus is a new pharmacologic therapy with a similar reprint address; for example, the antirestenosis agent sirolimus has recently been investigated as part of a stent platform combined with a biomimetic phosphorylcholine and BioLINX polymer for its biological activity, as well as its usefulness as an antiproliferative agent. Several clinical trials have been conducted to assess the safety and efficacy of the zotarolimus drug-eluting stent (Z-DES). Medtronic Medical Devices, a global leader in medical technology (United States), and Abbot Global Health Care and Research began clinical trials on the Z-DES in 2002 and will continue through 2021 (INDIA). Endeavor (E-Zes), Resolute (R-Zes), Resolute Integrity (I-Zes), and Resolute Onyx are the different forms of Z-DES that Medtronic has tested in clinical trials. In comparison to other DES, Z-DES was found to be safe in these clinical trials done across multiple nations and in a diverse demographic. This review helps understand the overall clinical trial of Z-DES.

3D printed polymeric stent design: Mechanical testing and computational modeling

Polymer-based bioresorbable scaffolds (BRS) aim to reduce the long-term issues associated with metal stents. Yet, first-generation BRS designs experienced a significantly higher rate of clinical failures compared to permanent implants. This prompted the development of alternative scaffolds, such as the poly(L-lactide-co-ε-caprolactone) (PLCL) solvent-casted stent, whose mechanical performance has yet to be addressed. This study examines the mechanical behavior of this novel scaffold across a wide range of parallel and radial compression diameters. The analysis highlights the scaffold’s varying responses under different loading conditions and provides insights into interpreting simulation model parameters to accurately reflect experimental results.Stents demonstrated a parallel crush resistance of 0.11 N/mm at maximum compression, whereas the radial forces were significantly higher, reaching up to 1.80 N/mm. Additionally, the parallel test keeps the stent in the elastic regime, with almost no regions exceeding 50 MPa of stress, while the radial test causes significant structural deformation, with localized plastic strain reaching up to 30 %. Results showed that underestimating yield strain in computational models leads to discrepancies with experimental results, being 5 % the most accurate value for matching computational and experimental results for PLCL solvent-casted stents.This comprehensive approach is vital for optimizing BRS design and predicting clinical performance.

Differential properties of drug-eluting stents and bioresorbable scaffolds in photon-counting computed tomography.

Differential properties of drug-eluting stents and bioresorbable scaffolds in photon-counting computed tomography.

Application of 3D Printing to Design and Manufacture Pancreatic Duct Stent and Animal Experiments.

Objective: Postoperative pancreatic fistula (POPF) is a common and challenging complication following pancreaticoduodenectomy (PD), occurring in 2% to 46% of cases. Despite various pancreaticojejunostomy techniques, an effective method to prevent POPF has not been established. This study aimed to develop and evaluate a novel 3D-printed biodegradable pancreatic duct stent to simplify the surgical process of pancreaticojejunostomy, reduce anastomotic complexity, and minimize postoperative complications. Methods: Data from 32 patients undergoing total laparoscopic pancreaticoduodenectomy were utilized. Preoperative CT scans were transformed into 3D reconstructions to guide the design and printing of customized stents using polylactic acid (PLA). The stents were assessed for mechanical integrity, surface texture, and thermal stability. Animal experiments were conducted on 16 mini pigs, with the experimental group receiving the novel stent and the control group receiving traditional silicone stents. Results: The 3D-printed stents demonstrated accurate dimensional replication and mechanical reliability. In the animal experiments, the experimental group showed no significant difference in postoperative complications compared to the control group. At 4 weeks post-surgery, CT scans revealed well-healed anastomoses in both groups, with no significant inflammation or other complications. Histological examination and 3D reconstruction models confirmed good healing and device positioning in the experimental group. Conclusion: The 3D-printed biodegradable pancreatic duct stent offers a promising solution for pancreaticojejunostomy, with comparable safety and efficacy to traditional methods. Further research is needed to validate its clinical application.

Acute Implantation of a Bioresorbable Polymer Scaffold in Patients With Complete Thoracic Spinal Cord Injury: A Randomized Controlled Trial (INSPIRE 2.0).

Traumatic spinal cord injury (SCI) remains a devastating condition with no proven effective treatment options available. In a prior single-arm study of patients with thoracic complete SCI (INSPIRE; ClinicalTrials.gov, NCT02138110), acute implantation of an investigational bioresorbable polymer scaffold (Neuro-Spinal Scaffold [NSS]) appeared to be safe through 24 months postimplantation and was associated with an American Spinal Injury Association Impairment Scale (AIS) conversion rate that exceeded historical controls. Here, we evaluated whether NSS implantation demonstrates probable benefit for safety and neurological recovery in patients with thoracic complete SCI vs standard-of-care spine surgery. INSPIRE 2.0 was a randomized, controlled, parallel, multicenter study conducted at Level I trauma centers in the United States (ClinicalTrials.gov, NCT03762655; funded by InVivo Therapeutics Corporation). Patients with AIS grade A, thoracic (T2-T12), nonpenetrating SCI requiring spine surgery ≤7 days postinjury were randomized (1:1, computer-generated allocation) to undergo NSS implantation or spine surgery alone (control group). Patients and follow-up International Standards for Neurological Classification of SCI assessors were blinded. A predefined study success criterion required the proportion of patients with improvement of ≥1 AIS grade at 6 months postsurgery (primary endpoint) to be ≥20% higher in the NSS group than in the control group. Target enrollment was reached (N = 20) with 10 patients randomized and analyzed in each group. At 6 months postsurgery, an improvement in the AIS grade was reported in 2 NSS patients (20%; both to AIS C) and 3 control group patients (30%; to AIS B [n = 2] or AIS C [n = 1]). No serious or unanticipated adverse device effects were reported. The study was closed to further follow-up because of not meeting its primary endpoint. In this small group of patients with thoracic complete (AIS A) SCI, implantation of an intraparenchymal bioresorbable scaffold did not produce probable clinical benefit. However, this study provides evidence that surgical intervention in an injured spinal cord parenchyma may be performed safely.

A Prospective, Randomized Trial of Bioresorbable Polymer Drug-Eluting Stents Versus Fully Bioresorbable Scaffolds in Patients Undergoing Coronary Stenting

Background: The performance of an everolimus-eluting bioresorbable scaffold (BRS) was inferior to an everolimus-eluting metallic drug-eluting stent (DES) with permanent polymer, mainly due the mechanical features of BRS technology. The performance of BRS as compared to metallic DES with bioresorbable polymers remains unstudied. Methods: This prospective, randomized, multicenter, clinical trial enrolled patients who underwent coronary stenting for de novo coronary lesions. Patients were randomly assigned to bioresorbable polymer everolimus-eluting stents (BP-EES) or everolimus-eluting BRS. The primary endpoint was percentage diameter stenosis (in-device) at 6- to 8-month angiographic surveillance. The main secondary endpoint was the device-oriented composite endpoint (DOCE) of cardiac death/target vessel-myocardial infarction/target lesion revascularization assessed after 12 months and 5 years. Results: The trial was prematurely terminated after the enrollment of 117 of 230 patients (BP-EES, n = 60; BRS, n = 57) due to safety issues associated with BRS technology. The primary endpoint of in-device diameter stenosis at angiographic surveillance was 12.5 ± 7.7% with BP-EES versus 19.3 ± 16.5% with BRS (p = 0.01). The DOCE occurred in 5.0% in the BP-EES group versus 12.3% of patients in the BRS group (hazard ratio [HR] 2.48, 95% confidence interval [CI] 0.64–9.58, p = 0.19) after 12 months and in 11.7% in the BP-EES group versus 26.4% of patients in the BRS group (HR 2.38, 95% CI 0.97–5.84, p = 0.06) after 5 years. Conclusions: BP-EES showed superior mid-term angiographic performance compared with BRS. Clinical event rates did not differ significantly between the groups up to 5 years of follow-up. These results should be interpreted with caution in view of the premature discontinuation of the study.

One-month DAPT after biodegradable-polymer everolimus-eluting stent implantation in women at high-bleeding risk: Insights from the POEM trial.

We conducted a prespecified subanalysis of the POEM trial to assess the association between sex and clinical outcomes following a short 1-month dual-antiplatelet-therapy (DAPT) period after percutaneous coronary intervention (PCI) with bioresorbable polymer everolimus-eluting stent (BP-EES) among patients at high bleeding risk (HBR). Shortening the DAPT period after PCI is an effective bleeding avoidance strategy with contemporary drug-eluting stents. Whether sex affects the risk of adverse events following PCI is still debated. Patients at HBR undergoing PCI with BP-EES were enrolled and treated with 1-month DAPT. If anticoagulation was needed, study participants received an oral anticoagulant (OAC) in addition to a P2Y12 inhibitor for 1 month, followed by OAC only thereafter. The primary endpoint was a composite of cardiac death, myocardial infarction, or definite/probable stent thrombosis at 12 months. We report sex-based outcomes of patients included in the POEM study. We enrolled 129 (29.1%) women and 314 (70.9%) men. Women were older, with lower hemoglobin levels, and worse renal function. Accordingly, they had a trend for a greater number of HBR criteria fulfilled and a higher PARIS bleeding score. However, they were not at a significantly higher risk for the primary endpoint (men vs. women: 5.17% vs. 3.94%; HR 1.30; 95% CI: 0.48-3.54, p = 0.61), or any of the hemorrhagic and ischemic secondary endpoints. This prespecified subanalysis of the POEM trial suggests that 1-month DAPT following PCI with BP-EES may be a safe and effective therapeutic strategy for women at HBR.