Bioabsorbable Scaffolds Research Articles

Primary Anterior Cruciate Ligament Repair With Hyaluronic Scaffold and Autogenous Bone Marrow Aspirate Augmentation in Adolescents With Open Physes

It is well known that the anterior cruciate ligament (ACL) is the main stabilizer to the anterior tibial translation in the knee. The current gold standard of treatment for such lesions is ACL reconstruction. However, there are notable disadvantages to ACL reconstruction that include loss of proprioception, donor site morbidity, incomplete return to high-demand sports, and the inability to restore normal kinematics of the knee joint. Additionally, in adolescents who have open physes, there is a risk of potential iatrogenic growth plate injury. Tibial-sided soft-tissue avulsion is a rare subtype of ACL injuries. This Technical Note presents a method for primary anatomic ACL repair with a bioabsorbable scaffold and bone marrow concentrate augmentation for an acute distal ACL injury. Our technique is an alternative to reconstruction as it allows the preservation of the native insertion site and has the potential to reduce the risk of posttraumatic osteoarthritis.

Different vascular healing process between bioabsorbable polymer-coated everolimus-eluting stents versus bioresorbable vascular scaffolds via optical coherence tomography and coronary angioscopy (the ENHANCE study: ENdothelial Healing Assessment with Novel Coronary tEchnology)

Recent clinical trials have raised concerns about the safety and efficacy of ABSORB™ bioresorbable vascular scaffolds (BVS). The difference in the vascular healing process between SYNERGY™ bioabsorbable polymer-coated everolimus-eluting stents (BP-EES) and BVS remains unclear. The aim of the ENHANCE study was to compare vascular healing on BP-EES versus BVS by optical coherence tomography (OCT) and coronary angioscopy (CAS) at 4- and 12-month follow-ups. This is a prospective, non-randomized, single center clinical trial. Thirteen eligible patients with multivessel disease were enrolled. BP-EES and BVS were simultaneously implanted in the same patients, but in different coronary vessels. Imaging follow-up with both OCT and CAS was completed in 11 patients at 12 months. Neointimal coverage rates were similar between the two groups based on OCT measurements. The neointimal thickness of BP-EES was significantly thicker at the 12th month than at the 4th month, whereas the neointimal thickness of BVS did not change between the measurements taken at the 4th and 12th month. Existence of intra-stent thrombus was significantly higher in the BVS group, compared to the BP-EES group. On the other hand, CAS revealed that red-thrombi and yellow-plaque were more frequently observed in BVS at 4 months and up to 12-month follow-ups than in BP-EES. These findings suggested that the evidence of instability remained up to 12 months in the vascular healing with BVS, compared to that with BP-EES. Vascular healing of the stented wall was recognized at the very early phase after BP-EES implantation. However, vascular healing with BVS was still incomplete after 12 months.

BIOABSORBABLE SCAFFOLDS FOR PERCUTANEOUS CORONARY INTERVENTIONS IN PATIENTS WITH CORONARY ARTERY DISEASE: PROBLEMS AND FUTURE PERSPECTIVES

Highlights. Bioabsorbable vascular scaffolds for percutaneous coronary interventions in multivessel coronaryartery disease patients and concomitant type 2 diabetes mellitus may increase the effectiveness of endovascular treatment and improve the long-term prognosis. The review article discusses recent data and evidences on the efficacy and safety of various stent generations for treating patients with coronary artery disease. The main complications commonly occurred following the implantation of drug-eluting stents in the long-term period are summarized, suggesting the rationale for the use of the next generation bioabsorbable vascular scaffolds in routine clinical practice. Bioabsorbable vascular scaffolds for endovascular treatment of patients with coronary artery disease show comparable efficacy compared with conventional drug-eluting stents. Particular attention is paid to the technical approaches of bioabsorbable vascular scaffold implantation, the use of intavascular imaging to control the implantation, as well as the timing of dual antiplatelet therapy in the postoperative period. The final term of the first-generation scaffold absorption, dual antiplatelet therapy, the effectiveness of bioabsorbable vascular scaffold-treated distal lesions and safety in patients with type 2 diabetes are highlighted. Future perspectives of using the next generation bioabsorbable vascular scaffolds that may improve the efficiency of percutaneous coronary interventions are presented.

TCT-193 Sustained Safety and Efficacy of Magmaris Bioabsorbable Scaffold: A 2-Year Follow-Up Analysis From Pooled Multicenter Italian Experience

Magnesium bioabsorbable metallic scaffold (Magmaris), with low thrombogenicity, short scaffolding time, and complete reabsorption at 12 months, is completely different from PLLA-based scaffolds. We evaluate 24-month clinical results in “real world” pooled patients with lesions suitable for

Elastomeric cardiopatch scaffold for myocardial repair and ventricular support.

Prevention of postischaemic ventricular dilatation progressing towards pathological remodelling is necessary to decrease ventricular wall deterioration. Myocardial tissue engineering may play a therapeutic role due to its capacity to replace the extracellular matrix, thereby creating niches for cell homing. In this experimental animal study, a biomimetic cardiopatch was created with elastomeric scaffolds and nanotechnologies. In an experimental animal study in 18 sheep, a cardiopatch was created with adipose tissue-derived progenitor cells seeded into an engineered bioimplant consisting of 3-dimensional bioabsorbable polycaprolactone scaffolds filled with a peptide hydrogel (PuraMatrix™). This patch was then transplanted to cover infarcted myocardium. Non-absorbable poly(ethyl) acrylate polymer scaffolds were used as controls. Fifteen sheep were followed with ultrasound scans at 6 months, including echocardiography scans, tissue Doppler and spectral flow analysis and speckle-tracking imaging, which showed a reduction in longitudinal left ventricular deformation in the cardiopatch-treated group. Magnetic resonance imaging (late gadolinium enhancement) showed reduction of infarct size relative to left ventricular mass in the cardiopatch group versus the controls. Histopathological analysis at 6 months showed that the cardiopatch was fully anchored and integrated to the infarct area with minimal fibrosis interface, thereby promoting angiogenesis and migration of adipose tissue-derived progenitor cells to surrounding tissues. This study shows the feasibility and effectiveness of a cardiopatch grafted onto myocardial infarction scars in an experimental animal model. This treatment decreased fibrosis, limited infarct scar expansion and reduced postischaemic ventricular deformity. A capillary network developed between our scaffold and the heart. The elastomeric cardiopatch seems to have a positive impact on ventricular remodelling and performance in patients with heart failure.

Effects of Transforming Growth Factor-β1 and Bone Morphogenetic Protein-2 on Bone Formation using a Bioabsorbable Scaffold at Palatal Sites in Rats

Effects of Transforming Growth Factor-β1 and Bone Morphogenetic Protein-2 on Bone Formation using a Bioabsorbable Scaffold at Palatal Sites in Rats

Clinical Application of Three-Dimensionally Printed Biomaterial Polycaprolactone (PCL) in Augmentation Rhinoplasty.

This clinical study aimed to investigate the safety and surgical outcome of three-dimensionally (3D) fabricated polycaprolactone (PCL) mesh in rhinoplasty. In particular, this study explored how a 3D-printed PCL mesh performs as a bioabsorbable scaffold after a long period following implantation. A retrospective review of 101 patients who received primary or secondary rhinoplasty with a PCL mesh was performed. Patient demographics and surgery-related outcomes were examined. Clinical efficacy and safety were evaluated using the Global Aesthetic Improvement Scale at postoperative 18months. From two revisional cases, a biopsy specimen of implanted PCL was acquired and histopathological analysis was performed. Of all the patients, 98.0% showed no postoperative infection-related foreign body reaction or distinct abnormal reaction, and the implants were observed to maintain long-term efficacy until 18-month follow-up. In patients who received spreader grafts, significant differences between preoperative and postoperative Cottle sign scores were found. Histopathological analysis showed features of adjacent tissue infiltration into pores of the PCL mesh and regeneration of neo-cartilaginous tissue and collagen around the mesh 20months after implantation. This study demonstrates that a novel biodegradable PCL mesh with a 3D structure is a safe and effective material for corrective rhinoplasty because it is easy to use and capable of maintaining its volume in the long term without foreign body response. This biocompatible material will have a wide range of applications as the most suitable alternative to nonabsorbable materials in rhinoplasty and reconstruction surgeries, such as fashioning spreader grafts and septal extension grafts. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Evaluation of Long-Term Inflammatory Responses after Implantation of a Novel Fully Bioabsorbable Scaffold Composed of Poly-L-lactic Acid and Amorphous Calcium Phosphate Nanoparticles

Objectives. Our previous studies have confirmed the superior biocompatibility of the poly-L-lactic acid/amorphous calcium phosphate (PLLA/ACP) scaffolds compared to PLLA scaffolds at 1-month. In the present study, the long-term inflammatory responses of PLLA/ACP scaffolds in a porcine coronary model have been explored. Methods. The 24 PLLA scaffolds and 24 PLLA/ACP scaffolds were implanted into the coronary arteries of 24 miniature pigs. Serum levels of ALT, AST, and CRP were measured before operation, as well as 1-month, 6-months, 12-months, and 24-months. The vascular segments were taken for pathomorphological observation. HE staining was used for the inflammatory score and fibrosis score. Immunohistochemical staining detected positive expression indexes of MMP-9 and NF-κB. The expression of inflammation-related proteins of IL-1 and IL-6 was detected by Western Blot in surrounding tissues of scaffolds. Results. There was no significant difference between the two groups in ALT, AST, and UR at different time points (P<0.05). The inflammation score in the PLLA/ACP group was lower than that in the PLLA group at 6-months, 12-months, and 24-months (P<0.05), and the fibrosis score was reduced in the PLLA/ACP group than that in the PLLA group at 12-months and 24-months (P<0.05). The expression of MMP-9 and NF-κB in the PLLA/ACP group was significantly less than that in the PLLA group at 6-months, 12-months, and 24-months (P<0.05). The protein expression of IL-1 in the PLLA/ACP group was decreased than that in the PLLA group at 12-months and 24-months (P<0.05). Furthermore, the protein expression of IL-1 was significantly lower than that in the PLLA group at 6-months, 12-months, and 24-months (P<0.01). Conclusions. The supplement of ACP nanoparticles can effectively reduce the long-term inflammatory reaction caused by PLLA and has good safety and biocompatibility. The novel bioabsorbable PLLA/ACP scaffold provides reliable guidance for the development and clinical application of bioabsorbable scaffolds in the future.

Use of Bioabsorbable Tissue Reinforcement Reduces Incidence of Internal Hernia in Roux-en-Y Gastric Bypass Patients

Internal hernias are one of the most devastating late, postsurgical complications associated with laparoscopic Roux-en-Y gastric bypass (LRYGB). The objective of this study was to determine whether placement of a bioabsorbable tissue matrix in soft tissue defects after gastric bypass resulted in a lower incidence of internal hernia development. Prospective database was used to identify all patients who underwent LRYGB between January 2002 and January 2016. These patients were then retrospectively reviewed to determine the development of internal hernia. Before 2009, the retro-Roux defect was left open during the primary operation and the defect at the jejunojejunostomy was closed with sutures or staples. Beginning in 2009, all soft tissue internal defects were reinforced with an 8 cm × 8-cm piece of bioabsorbable matrix. The incidence of subsequent internal hernia development was compared between these two groups: no bioabsorbable matrix versus use of a bioabsorbable matrix. A total of 2771 patients underwent LRYGB during our study period. From these, 1215 procedures were performed without tissue reinforcement and 1556 were performed using a bioabsorbable matrix. During the study period, 274 patients developed an internal hernia. Patients who did not have tissue reinforcement at closure had a significantly higher internal hernia rate [225/1215 (18.5%) vs 49/1556 (3.1%), P < 0.005]. This study demonstrates a statistically significant reduction in internal hernia formation after LRYGB with the addition of a bioabsorbable tissue matrix. Although prospective studies are needed, early evidence suggests that reinforcement with a bioabsorbable tissue scaffold is an effective method for minimizing internal hernias after LRYGB.

Regeneration of Transected Recurrent Laryngeal Nerve Using Hybrid-Transplantation of Skeletal Muscle-Derived Stem Cells and Bioabsorbable Scaffold.

Hybrid transplantation of skeletal muscle-derived multipotent stem cells (Sk-MSCs) and bioabsorbable polyglyconate (PGA) felt was studied as a novel regeneration therapy for the transected recurrent laryngeal nerve (RLN). Sk-MSCs were isolated from green fluorescence protein transgenic mice and then expanded and transplanted with PGA felt for the hybrid transplantation (HY group) into the RLN transected mouse model. Transplantation of culture medium (M group) and PGA + medium (PGA group) were examined as controls. After eight weeks, trans-oral video laryngoscopy demonstrated 80% recovery of spontaneous vocal-fold movement during breathing in the HY group, whereas the M and PGA groups showed wholly no recoveries. The Sk-MSCs showed active engraftment confined to the damaged RLN portion, representing favorable prevention of cell diffusion on PGA, with an enhanced expression of nerve growth factor mRNAs. Axonal re-connection in the HY group was confirmed by histological serial sections. Immunohistochemical analysis revealed the differentiation of Sk-MSCs into Schwann cells and perineurial/endoneurial cells and axonal growth supportive of perineurium/endoneurium. The number of axons recovered was over 86%. These results showed that the stem cell and cytokine delivery system using hybrid transplantation of Sk-MSCs/PGA-felt is a potentially practical and useful approach for the recovery of transected RLN.

TCT-702 Magnesium-metallic bioabsorbable scaffold (Magmaris) long-term results. Analysis from pooled multicentre italian experience.

Magnesium bioabsorbable metallic scaffold (MagmarisTM), with low trombogenicity, short scaffolding time, metallic performance and complete reabsorption at 12 months, is completely different from PLLA-based scaffold. We evaluate 12 months clinical results in “real world” pts with lesions

TCT-388 Real World Follow- up one year Of The Novel MeRes100.

Safety concerns with 1st generation of bioabsorbable vascular scaffolds(BRS) have prompted the development of next generation of these devices, focused on thinner struts and faster resorption time. Recently developed, the MeRes100 (Meril Life Sciences) is a sirolimus-eluting (1.25 mg/mm2) BRS, which

Six-month evaluation of novel bioabsorbable scaffolds composed of poly-L-lactic acid and amorphous calcium phosphate nanoparticles in porcine coronary arteries.

Objective Using coronary angiography and intravascular ultrasound methods to evaluate the performance of the novel fully bioabsorbable scaffold (NFBS) composed of poly-L-lactic acid/amorphous calcium phosphate (PLLA/ACP) at six-month follow-up by comparing with PLLA scaffolds Methods Twelve PLLA/ACP scaffolds and 12 PLLA scaffolds were implanted into the coronary arteries of 12 miniature pigs. Quantitative coronary angiography (QCA) was used to measure the reference vessel diameter (RVD), mean lumen diameter (MLD) and late lumen loss (LLL). According to IVUS images, we calculated the strut malapposition rate (SMR) at post implantation, strut overlap rate (SOR), reference vessel area (RVA), mean stent area (MSA), mean lumen area (MLA) and luminal patency rate (LPR) at six-month follow-up. The radial strength of the scaffold was evaluated using a catheter tensile testing machine. Results QCA results indicated that, at six month, MLD of PLLA/ACP scaffolds was greater than those of PLLA scaffolds (2.47 ± 0.22 mm vs. 2.08 ± 0.25 mm, P < 0.05); LLL of PLLA/ACP scaffolds was less than those of PLLA scaffolds (0.42 ± 0.20 mm vs. 0.75 ± 0.22 mm, P < 0.05). IVUS results showed the SMR and SOR were all significantly less with the PLLA/ACP scaffolds than the PLLA scaffolds (5.84% ± 3.56% vs. 17.72% ± 4.86%, P < 0.05) (6.17% ± 4.63% vs. 17.65% ± 4.29%, P < 0.05). MSA, MLA and LPR of the PLLA/ACP scaffolds were all greater than those of PLLA scaffolds (6.35 ± 0.45 mm2 vs. 5.35 ± 0.51 mm2, P < 0.05) (4.76 ± 0.46 mm2 vs. 3.77 ± 0.46 mm2, P < 0.05) (78.01% ± 12.29% vs. 61.69% ± 9.76%, P < 0.05). Radial strength of PLLA/ACP scaffold at six month was greater than that of PLLA scaffold (76.33 ± 3.14 N vs. 67.67 ± 3.63 N). Conclusion The NFBS had less stent recoil, better lumen patency rate and greater radial strength than PLLA scaffolds. The results suggest the NFBS scaffolds can maintain the structural strength and functional performance, which are effective for up to six months when implanted in porcine coronary arteries.

SYNTAX II and SYNTAX III trials: what is the take home message for surgeons?

Percutaneous coronary intervention (PCI) has evolved greatly in the last 40 years since its introduction by Andreas Grüntzig in 1977. Since then, we've observed an evolution in balloons, the development of stents, changes in stent structure, development of drug eluting stents, improvements in strut design, thickness and even their polymeric coating. Most recently we saw the rise and "fall" of bioabsorbable scaffolds for PCI. Trials with the most diverse devices for PCI and diagnostic techniques have been conducted. Two of the most recent trials were reported in the last year and deserve special attention-SYNTAX II and SYNTAX III. These trials are completely different in design but present valuable information for doctors managing coronary artery disease (CAD). Both trials take into account contemporary technology for assessing and treating CAD. The first uses so-called "state-of-the-art" PCI and compares the outcomes of that approach with the outcomes of the PCI arm of the pivotal SYNTAX trial. SYNTAX III Revolution on the other hand does not focus on clinical endpoints: it is a blinded trial that does not randomize patients but randomizes doctors ("the heart team") to make a decision on the best treatment for complex CAD. This decision was based either on multi-slice CT with physiological assessment using FFRCT or on conventional angiography. In this review we bring the most important aspects of those trials and the key messages for surgeons together; also, what the surgeon may expect in the future after the publication of these interesting concepts.

Technological Advances in Stent Therapies: a Year in Review.

Stent technology has rapidly evolved since the first stainless steel bare metal stents with substantial developments in scaffolding, polymer, drug choice, drug delivery, and elution mechanisms. Most recently, there has been the evolution of bioabsorbable vascular scaffolds, potentially eliminating the need for long-term foreign object retention. These rapid developments have led to an ever-expanding selection of new stents, making the choice of which to use in which patient challenging. Operators must balance potential short- and long-term clinical ramifications, namely stent thrombosis, in-stent restenosis, target lesion revascularization, and target lesion failure. In this review, we hope to provide insight for interventional cardiologists on the details of stent technology and how this impacts outcomes, stent selection, and duration of dual-antiplatelet therapy duration post drug-eluting stent implantation.

Comparative Study of Tissue Affinity, Chemical Characteristics of Cultured and Natural Coral as a Bioabsorbable Scaffold

Comparative Study of Tissue Affinity, Chemical Characteristics of Cultured and Natural Coral as a Bioabsorbable Scaffold

Endothelial shear stress 5 years after implantation of a coronary bioresorbable scaffold.

As a sine qua non for arterial wall physiology, local hemodynamic forces such as endothelial shear stress (ESS) may influence long-term vessel changes as bioabsorbable scaffolds dissolve. The aim of this study was to perform serial computational fluid dynamic (CFD) simulations to examine immediate and long-term haemodynamic and vascular changes following bioresorbable scaffold placement. Coronary arterial models with long-term serial assessment (baseline and 5 years) were reconstructed through fusion of intravascular optical coherence tomography and angiography. Pulsatile non-Newtonian CFD simulations were performed to calculate the ESS and relative blood viscosity. Time-averaged, systolic, and diastolic results were compared between follow-ups. Seven patients (seven lesions) were included in this analysis. A marked heterogeneity in ESS and localised regions of high blood viscosity were observed post-implantation. Percent vessel area exposed to low averaged ESS (<1 Pa) significantly decreased over 5 years (15.92% vs. 4.99%, P < 0.0001) whereas moderate (1-7 Pa) and high ESS (>7 Pa) did not significantly change (moderate ESS: 76.93% vs. 80.7%, P = 0.546; high ESS: 7.15% vs. 14.31%, P = 0.281), leading to higher ESS at follow-up. A positive correlation was observed between baseline ESS and change in lumen area at 5 years (P < 0.0001). Maximum blood viscosity significantly decreased over 5 years (4.30 ± 1.54 vs. 3.21± 0.57, P = 0.028). Immediately after scaffold implantation, coronary arteries demonstrate an alternans of extremely low and high ESS values and localized areas of high blood viscosity. These initial local haemodynamic disturbances may trigger fibrin deposition and thrombosis. Also, low ESS can promote neointimal hyperplasia, but may also contribute to appropriate scaffold healing with normalisation of ESS and reduction in peak blood viscosity by 5 years.

Everolimus‐eluting bioabsorbable vascular scaffolds (BVS) versus everolimus‐eluting metallic stents (EES) at 3 years: Systematic review and meta‐analysis

AbstractBackgroundThis systematic review and meta‐analysis aimed to assess the efficacy and safety of the Absorb bioabsorbable vascular scaffold (BVS) versus everolimus‐eluting metallic stents (EES) at 3 years.MethodsWe searched MEDLINE, EMBASE, CENTRAL and relevant websites for articles published between 30 November 2006 and 18 December 2017. The primary efficacy outcome was target lesion revascularization (TLR), and the primary safety outcome was definite or probable stent (scaffold) thrombosis. Secondary outcomes included target lesion failure, myocardial infarction (MI), death, all revascularization and a patient‐oriented composite end‐point. We derived odds ratios (ORs) for the outcomes according to a fixed‐effects model. His study was registered with PROSPERO (CRD42017084290).ResultsWe included five trials comprising data for 3,575 patients randomized to receive BVS (n = 2,256) or EES (n = 1,319). Patients treated with the BVS had a non‐statistically significant increased risk of TLR (OR 1.30 [95% CI 0.95–1.78]; p = 0.10). Patients treated with the BVS had a higher risk of definite or probable stent thrombosis (OR 2.68 [95% CI 1.57–4.58]; p &lt; 0.001), target lesion failure (1.41 [1.12–1.78]; p = 0.004), MI (1.49 [1.13–1.98]; p = 0.005) and a patient‐oriented composite end‐point (1.21 [1.01–1.44]; p = 0.038) than those treated with an EES. Patients treated with the BVS had no statistically significant difference in death (0.80 [0.51–1.25]; p = 0.325) and all revascularization (1.12 [0.91–1.40]; p = 0.052) compared to those treated with an EES.ConclusionEverolimus‐eluting bioabsorbable vascular scaffolds are inferior to everolimus‐eluting metallic stents at 3 years.

Long-Term Follow-Up of Bioabsorbable Scaffolds: A Single-Centre Experience

Background: Bioabsorbable vascular scaffolds (BVS) provide temporary drug-eluting vessel support and gradual resorption of the polymer backbone, facilitating vessel healing without a permanent prosthesis following coronary intervention. Recent data of late and very late adverse events continue to emerge.

Enhanced performance of magnesium alloy for drug-eluting vascular scaffold application

Bio-absorbable magnesium alloys drug-eluting vascular scaffold was developed to resolve the defect of permanent metal and drug-eluting stents, most notably a chronic vessel wall inflammation and the risk of stent thrombosis. Nevertheless, violent chemical reaction and rapid degradation under physiological conditions limits their application. Furthermore, multifunctional drug-eluting stents which could reduce the formation of thrombus and repair the damaged vessels need more attention to fundamentally cure the coronary artery disease. Herein, a drug delivery system (Mg/MgO/PLA-FA) which can realize sustainable release of ferulaic acid was designed via anodic oxidation process and dip coating process. Electrochemical tests and immersion experiments showed that the superior anticorrosion behavior, it is due to the dense MgO-PLA composite layer. The released ferulaic acid can effectively decrease platelets adhesion and aggregation during the early stage of implantation. Besides, hemolysis tests showed that the composite coatings endowed the Mg alloy with a low hemolysis ratio. The Mg/MgO/PLA-FA composite materials may be appropriate for applications on biodegradable Mg alloys drug-eluting stents.