Surgical treatment of tracheal stenosis in children / 中华胸心血管外科杂志

Objective:To investigate the common types, surgical treatment and effects of tracheal stenosis in children.Methods:A total of 23 children with tracheal stenosis in our hospital from December 2017 to August 2020 were retrospectively reviewed, including 14 males and 9 females. The mean age at operation was(8.9±5.8)months(range: 2-3 months) and the mean weight was(6.4±2.3)kg(range: 4.2-10.5 kg). The common types of tracheal stenosis were complete tracheal ring in 9 children, tracheomalacia in 10 and subglottic membranous annular hyperplasia in 4. The type of congenital heart diseases included 10 patients of pulmonary artery sling, 1 of tetralogy of Fallot, 5 of ventricular septal defect, 1 of pulmonary atresia, and 1 of right aortic arch with aberrant left subclavian artery. Slide tracheoplasty was performed in 9 patients, external splint in 8, endotracheal stent in 2 and tracheal dilation in 4. All children were followed up after 1, 3, 6, and 12 months of operation with CT and bronchoscopy.Results:There was 1 death in all 23 patients and the mortality was 4.3%, which died of granulation tissue hyperplasia after slide tracheoplasty. Reoperation was performed in 1 patient with endotracheal stent. All patients were followed for 1 to 24 months. Clinical symptoms of tracheal stenosis disappeared and the results of CT and bronchoscopy were satisfied.Conclusion:Slide tracheoplasty is the effective surgical method for complete trachea ring. 3D printing bioresorbable external splint is a promising method for the treatment of tracheomalacia.

Magnesium versus poly-L-lactic acid bioresorbable scaffolds: in vivo optical coherence tomography comparison of mechanical performance / Andamiajes bioresorbibles de magnesio versus poliméricos: comparación in vivo de su comportamiento mecánico por OCT

Abstract Background: Different mechanical properties have been suggested for metallic bioresorbable vascular scaffolds (BVS) in comparison to polymeric BVS. We aim to evaluate the acute mechanical performance of Magmaris® scaffold in comparison to Absorb®. Materials and Methods: Two groups of 10 coronary lesions treated with Magmaris® and Absorb® 1.1 (20584 vs. 21016 struts) were compared. In all cases, optical coherence tomographic (OCT) images were acquired after scaffold deployment. Baseline clinical, angiographic, and procedural characteristics were compared, including OCT evaluations. Results: No baseline clinical or angiographic significant differences were found between groups. The most common indication for revascularization was effort angina (60% vs. 70% p = 0.45) with no ST-elevation myocardial infarction (MI) cases. Main target artery was left anterior descending, with a mean vessel diameter of 3.46 ± 0.23 in Absorb® and 3.52 ± 0.19mm in Magmaris® groups (p = 0.56). All cases underwent pre- and post-dilatation with a procedural success rate of 100%. OCT analyses showed larger scaffold and vessel diameters in Magmaris® group: 3.11 ± 0.38 mm versus 3.07 ± 0.36 mm, p = 0.03 and 4.12 ± 0.51 mm versus 4.04 ± 0.46 mm, p = 0.04. Despite the application of slightly higher postdilatation pressures to Magmaris® devices (18.01 ± 2.15 vs. 17.20 ± 3.80 atm, p = 0.05), significantly lower percentages of disrupted and malapposed struts were identified within Magmaris® scaffolds (0.15% vs. 0.27%, p = 0.03 and 1.06% vs. 1.46% p = 0.01). No cardiac death, target vessel-related MI, or clinically driven target lesion revascularization was reported in a 30-day follow-up. Conclusion: Mechanical properties of Magmaris® scaffold allow achieving larger vessel and scaffold diameters in a safe manner, with lower rates of malapposition and scaffold disruption.

Resumen Introducción: Se ha sugerido la presencia de un distinto comportamiento mecánico entre los dos grupos principales de dispositivos bioresorbibles: metálicos y poliméricos. En este estudio evaluamos el comportamiento mecánico agudo del andamiaje bioresorbible metálico Magmaris® frente al del polimérico Absorb®. Métodos: Se compararon dos grupos de 10 lesiones coronarias tratadas con Magmaris® y Absorb® 1.1 (20584 vs. 21016 struts). En todos los casos se realizó estudio postimplante del dispositivo mediante tomografia de coherencia óptica (OCT). Se compararon las características basales clínicas y angiográficas, así como aspectos del procedimiento (incluídos los estudios de OCT) entre ambos grupos. Resultados: No se encontraron diferencias clínicas o angiográficas estadísticamente significativas entre ambos grupos. La indicación más frecuente de revascularización coronaria fué la presencia de angina de esfuerzo (60% vs. 70% p = 0.45), sin incluirse casos de IAMCEST. La arteria descendente anterior fué el principal vaso diana, con un diámetro medio de 3.46 ± 0.23 mm en el grupo de Absorb® y de 3.52 ± 0.19mm en el grupo de Magmaris® (p = 0.56). En todos los casos se realizó pre y postdilatación, con una tasa de éxito del procedimiento del 100%. Los estudios mediante OCT demostraron un mayor diámetro de stent y del vaso en el grupo de Magmaris®: 3.11 ± 0.38mm versus 3.07 ± 0.36 mm, p = 0.03 y 4.12 ± 0.51mm versus 4.04 ± 0.46mm, p = 0.04. A pesar de someter a los dispositivos Magmaris® a presiones de postdilatación ligeramente superiores (18.01 ± 2.15 vs. 17.20 ± 3.80 atm, p = 0.05), se identificó un menor porcentaje estadísticamente significativo de struts rotos o malapuestos en dicho grupo (0.15% vs. 0.27 %, p = 0.03 y 1.06 % vs. 1.46% p = 0.01). En un seguimiento a 30 días no se registraron eventos mayores: muerte cardíaca, IM relacionado con vaso diana o TLR. Conclusión: Las propiedades mecánicas del scaffold metálico bioresorbible Magmaris® permiten alcanzar mayores diámetros de stent y vaso de forma segura tras su implante, con una baja tasa de malaposición y disrupción.

Influence of Thickness and Width of Bioabsorbable Vascular Stent on Local Hemodynamics / 中国医疗器械杂志

The study reconstructed vascular model by the realistic Optical Coherence Tomography (OCT) data to investigate the influence of the local hemodynamics caused by different thickness and width of bioresorbable vascular scaffold (BRS) implantation in Left Anterior Descending (LAD) artery. The study explored the relationship between the stent structure and thrombus, and the result can provide a valuable reference for the optimal design of BRS.

Stents bronquiales bioabsorbibles y factores que afectan su velocidad de degradación / Bioresorbable bronchial stents and factors that affect the rate of degradation

Resumen Las causas que pueden conducir a la obstrucción de la vía aérea central pueden ser de origen funcional, por obstrucción de la luz, por lesión orgánica parietal o compresión extrínseca; a su vez, también pueden agruparse en obstrucciones malignas y no malignas. Cuando una obstrucción reduce el 50 % de la luz de la vía aérea causa síntomas debilitantes y es una de las indicaciones para implantar un stent bronquial. Los stents bronquiales actualmente disponibles son una solución incompleta para las obstrucciones de las vías aéreas. Por otra parte, un stent bronquial ideal debe cumplir con muchas características, tales como ser biocompatible, en muchos casos bioabsorbible, radio opaco, que no genere reacción inflamatoria, tener características similares a las de la vía aérea para disminuir la acumulación de secreciones, entre otras. Por esta razón los stents bronquiales bioabsorbibles se presentan como una alternativa atractiva que ofrece ciertas ventajas, aunque aún se encuentran en desarrollo. El presente artículo busca describir los avances alrededor de los stents bronquiales bioabsorbibles y los factores que afectan la degradación de los polímeros con los cuales se han fabricado.

Abstract The causes that can lead to obstruction of the central airway can be of functional origin, due to obstruction of the light, organic parietal lesion or extrinsic compression; in turn, they can also be grouped into malignant and non-malignant obstructions. When an obstruction reduces more than 50% of the lumen of the airway causes debilitating symptoms and is an indication to implant a bronchial stent. The bronchial stents currently available are an incomplete solution for obstructions of the airways. On the other hand, an ideal bronchial stent must comply with many characteristics, such as being biocompatible, in many cases bioabsorbable, radio opaque, that does not generate an inflammatory reaction, having characteristics similar to those of the airway to decrease the accumulation of secretions, between others. For this reason, bioabsorbable bronchial stents are presented as an attractive alternative that offers certain advantages, although they are still in development. This article seeks to describe the advances around the bioabsorbable bronchial stents and the factors that affect the degradation of the polymers with which they have been manufactured.

Low major adverse cardiac event rates following bioresorbable vascular scaffold implantation: Impact of implantation technique on treatment outcomes

Background and objective Studies conducted across the world have reported that the rates of major adverse cardiac events (MACE) following the use of bioresorbable vascular scaffolds (BVS) are comparable to that noted with traditional drug eluting stents (DES). However, there is limited data on the immediate and medium-term clinical outcomes following the use of the Absorb BVS (Abbott Vascular, Santa Clara, SA) in the Indian context. This study was conducted to determine real-world evidence on the immediate and medium-term clinical outcomes in all patients undergoing percutaneous coronary intervention (PCI) with the Absorb BVS. Methods Data of all patients who were treated with Absorb BVS at our center were evaluated. Between December 2012 and October 2016, 142 patients underwent PCI with BVS. The MACE rates during hospitalization, at 30 days, 3 months, 6 months after PCI, and every 6 months thereafter were the primary endpoints evaluated with median follow up of 13 months. Results Mean age of the study participants was 53.7 ± 11.8 years. Intravascular ultrasound imaging was performed in 15.34% of patients. Predilatation and postdilatation were performed in 81.8% and 84.6% of scaffolds, respectively. There were no episodes of MACE during hospitalization. However, 1 BVS-related MACE was observed at the 1-month (0.7%) as well as at the ≥12 month (0.8%) follow up visits. At the 6- and 12-month follow up visits, 2 (1.5%) and 3 (2.5%) non-BVS-related MACEs, respectively, were recorded. Conclusion The use of Absorb BVS in this real-world experience was associated with very good immediate and medium-term clinical outcomes.

Bioresorbable Scaffolds in Coronary Intervention: Unmet Needs and Evolution

Bioresorbable scaffolds (BRS) represent a novel paradigm in the 40-year history of interventional cardiology. Restoration of cyclic pulsatility and physiologic vasomotion, adaptive vascular remodeling, plaque regression, and removal of the trigger for late adverse events are expected BRS benefits over current metallic drug-eluting stents. However, first-generation BRS devices have significant manufacturing limitations and rely on optimal implantation technique to avoid experiencing an excess of clinical events. There are currently at least 22 BRS devices in different stages of development, including many trials of device iterations with thinner (<150 µm) struts than first-generation BRS. This article reviews the outcomes of commercially available and potentially upcoming BRS, focusing on the most recent stages of clinical development and future directions for each scaffold type.

Bioresorbable Vascular Scaffold: A Focused Review on Development and Preclinical Studies / 中国医疗器械杂志

Bioresorbable vascular scaffolds(BVS) are new treatment strategies of percutaneous coronary intervention. They have been introduced to overcome limitations of bare metal stents (BMS) and drug-eluting stents(DES), since they provide temporary scaffolding and then disappear, liberate the treated vessel from cage. In this article, we review the current status and problems of BVS, various tests required before gaining regulatory approval for clinical use.

Early experience and favorable clinical outcomes of everolimus-eluting bioresorbable scaffolds for coronary artery disease in Korea

BACKGROUND/AIMS: Compared with metallic drug-eluting stents (DES), bioresorbable vascular scaffolds (BVS) may further improve long-term outcomes of percutaneous coronary intervention (PCI) in patients with coronary artery disease. We report our early experience with BVS in Korea. METHODS: We evaluated 105 consecutive patients with BVS implanted at Asan Medical Center, Korea between October 21, 2015 and June 3, 2016. Angiographic results, and in-hospital and 6-month clinical outcomes were assessed. RESULTS: A total of 134 BVS were implanted to treat 115 lesions. The mean age was 62 ± 10.5 years; 85 patients (81%) were males, 26 patients (25%) were presented with acute coronary syndrome. Among 115 lesions treated with BVS, 76 (66.1%) were B2/C type, 27 (23.5%) were bifurcation lesions, and four (3.5%) were chronic total occlusion. Pre-dilation and post-dilation using high-pressure non-compliant balloon was performed in 104 lesions (90.4%) and 113 lesions (98.2%), respectively. During the procedure, intravascular imaging was used for all patients (100%; intravascular ultrasound 89 and optical coherence tomography 40 patients). Device success rate was 100%. In-segment and in-scaffold acute again were 1.1 ± 0.6 and 1.3 ± 0.5 mm, respectively. Periprocedural myocardial infraction occurred in four patients (3.8%). No deaths, stent thrombosis, or urgent revascularizations occurred either during hospitalization or the follow-up period. CONCLUSIONS: In this single-center experience, implantation of BVS with intravascular imaging support was feasible and early clinical outcomes were excellent. Evaluation of long-term efficacy and safety of BVS and its feasibility in clinical use for a broader range of lesions is warranted.

Hydrocortisone release from tablets based on bioresorbable poly(ether-ester-urethane)s

Abstract Bioresorbable linear poly(ether-ester-urethane)s with different hydrophilic characteristics were synthesized from triblock copolymers of poly(ε-caprolactone)-poly(ethylene oxide)-poly(ε-caprolactone) (PCL-PEO) as macrodiols, and L-lysine diisocyanate (LDI) or hexamethylenediisocyanate (HDI) were used as the required diisocyanates. Macrodiols were obtained by ring-opening polymerization (ROP) of ε-caprolactone (CL). Polyurethanes were synthesized by the reaction of the triblock copolymers with LDI or HDI in solution using stannous 2-ethylhexanoate as catalyst. Polyurethane tablets were fabricated and investigated as prospective drug delivery systems. The effect of the PEO content on the polymers' performance as drug carriers was evaluated. It was found that water provoked more swelling and erosion of polymers with higher contents of PEO. The hydrocortisone release profiles were analyzed using the Ritger-Peppas approximation. An anomalous release behaviour (values of n higher than 0.5) was found for most of the analyzed samples.

A review of bioresorbable scaffolds: hype or hope?

In the field of percutaneous coronary intervention, the evolution of coronary metal stents has been well established for the past three decades, but research on bioresorbable scaffolds has only gained momentum in the recent past. Although second-generation drug-eluting metal stents are the gold standard for the treatment of obstructive coronary artery disease, a few drawbacks exist. The development of bioresorbable scaffolds is an attempt to overcome the limitations of metal stents. This review highlights the rationale for the bioresorbable scaffold, its properties and potential applications. It also focuses on the current evidence and concerns regarding the application of the bioresorbable scaffold in day-to-day practice.

Bioresorbable Vascular Scaffold Korean Expert Panel Report

Bioresorbable vascular scaffold (BRS) is an innovative device that provides structural support and drug release to prevent early recoil or restenosis, and then degrades into nontoxic compounds to avoid late complications related with metallic drug-eluting stents (DESs). BRS has several putative advantages. However, recent randomized trials and registry studies raised clinical concerns about the safety and efficacy of first generation BRS. In addition, the general guidance for the optimal practice with BRS has not been suggested due to limited long-term clinical data in Korea. To address the safety and efficacy of BRS, we reviewed the clinical evidence of BRS implantation, and suggested the appropriate criteria for patient and lesion selection, scaffold implantation technique, and management.

Intervencionismo coronario complejo con solapamiento de dispositivos biorreabsorbibles. Reporte de caso y revisión de nuevas perspectivas en el uso de dispositivos biorreabsorbibles guiado por tomografía de coherencia óptica / Complex coronary intervention with overlapping of bioresorbable scaffolds. Case report and new insights review in the use of bioresorbable vascular scaffolds guided by optical coherence tomography

Resumen La historia del intervencionismo percutáneo coronario ha tenido en los últimos años una evolución notable. Actualmente en México están disponibles los dispositivos vasculares biorreabsorbibles, los cuales tienen indicaciones precisas, y ofrecen una nueva opción en el intervencionismo coronario. En este trabajo presentamos el caso, y revisamos la evidencia publicada, para una nueva opción de intervención con estos dispositivos, un caso complejo con solapamiento de 3 dispositivos vasculares biorreabsorbibles guiado mediante tomografía de coherencia óptica.

Abstract In recent years, the history of percutaneous coronary intervention has had a remarkable evolution. Currently, in México are available the bioresorbable vascular scaffolds which have a very precise indications, and offer a new option in coronary intervention. We present the case and review of the published evidence, a new option for intervention with these devices, a complex case with 3 overlapping bioresorbable vascular scaffolds guided by optical coherence tomography.

Bioresorbable Plates In Management Of Mandibular Angle Fracture

Rigid internal fixation of the jaw bones is a routine procedure for the management of facial fractures. Titanium plates and screws are routinely used for this purpose. The limitations of this system have led to the development of plates manufactured from bioresorbable materials which, in some cases, omits the necessity for the second surgery. However, concerns remain about the stability of fixation and the length of time required for their degradation and the possibility of foreign body reactions. The following case report tries to evaluate the treatment of mandibular angle fracture via a single biodegradable plate and address complication such as malocclusion, infection, soft tissue dehiscence and nonunion in these patients.

The Effectiveness of Polylactic Acid Bioresorbable Film in the Prevention of Adhesion Formation in Tendons / 대한정형외과학회잡지

PURPOSE: To evaluate the effectiveness of a polylactic acid bioresorbable film in the prevention of tendon adhesion after tendon repair. MATERIALS AND METHODS: Twenty-four adult rabbits (48 cases) were used in this study. In the first (control) group, the flexor tendons of the third toe were cut and a tenorrhaphy was performed. The 2nd group was injected with hyaluronic acid between the tendon and tendon sheath after suturing. The 3rd group underwent an enveloping of the tendon with polylactic acid film, followed by tenorrhaphy. The test animals were euthanized at 1, 2, 3, and 6 weeks after surgery, and the histology and biomechanics were evaluated. RESULTS: Microscopic evaluations revealed fibrosis to be most apparent in group 1, while groups 2 and 3 showed no significant differences. The biomechanical tests, which were carried out using a Universal Testing Machine, revealed that an increase in adhesion strength with time. At 6 weeks after surgery, group 1 exhibited an adhesion strength that was 2.5-3 times greater than that exhibited by groups 2 and 3. Group 2 had a higher adhesion strength than group 3, but this difference was not statistically significant. CONCLUSION: Increases in granulation tissue and fibrosis during the healing of sutured tendons were observed, and the tested polylactide resorbable film was found to be effective in reducing the level of adhesion formation after tendon repair.

The prognosis of fixation of mandibular fractures with biodegradable plates and screws

The effect of the bioresorbable collagen membrane on the regeneration of bone defect by using the mixture of autograft and xenograft bone / 대한치과보철학회지

STATEMENT OF PROBLEM: In cases where bony defects were present, guided bone regenerations have been performed to aid the placement of implants. Nowadays, the accepted concept is to isolate bone from soft tissue by using barrier membranes to allow room for generation of new bone. Nonresorbable membranes have been used extensively since the 1980's. However, this material has exhibited major shortcomings. To overcome these faults, efforts were made to develop resorbable membranes. Guided bone regenerations utilizing resorbable membranes were tried by a number of clinicians. Bio-Gide. is such a bioresorbable collagen that is easy to use and has shown fine clinical results. PURPOSE: The aim of this study was to evaluate the histological results of guided bone regenerations performed using resorbable collagen membrane(Bio-Gide.) with autogenous bone, bovine drived xenograft and combination of the two. Surface morphology and chemical composition was analyzed to understand the physical and chemical characteristics of bioresorbable collagen membrane and their effects on guided bone regeneration. MATERIAL AND METHODS: Bioresorbable collagen membrane (Bio-Gide.), Xenograft Bone(Bio-Oss), Two healthy, adult mongrel dogs were used. RESULTS: 1. Bioresorbable collagen membrane is pure collagen containing large amounts of Glysine, Alanine, Proline and Hydroxyproline. 2. Bioresorbable collagen membrane is a membrane with collagen fibers arranged more loosely and porously compared to the inner surface of canine mucosa : This allows for easier attachment by bone-forming cells. Blood can seep into these spaces between fibers and form clots that help stabilize the membrane. The result is improved healing. 3. Bioresorbable collagen membrane has a bilayered structure : The side to come in contact with soft tissue is smooth and compact. This prevents soft tissue penetration into bony defects. As the side in contact with bone is rough and porous, it serves as a stabilizing structure for bone regeneration by allowing attachment of bone-forming cells. 4. Regardless of whether a membrane had been used or not, the group with autogenous bone and Bio-Oss. filling showed the greatest amount of bone fill inside a hole, followed by the group with autogenous bone filling, the group with blood and the group with Bio-Oss. Filling in order. 5. When a membrane was inserted, regardless of the type of bone substitute used, a lesser amount of resorption occurred compared to when a membrane was not inserted. 6. The border between bone substitute and surrounding bone was the most indistinct with the group with autogenous bone filling, followed by the group with autogenous bone and Bio-Oss. filling, the group with blood, and the group with Bio-Oss. filling. 7. Three months after surgery, Bio-Gide. and Bio-Oss. were distinguishable. CONCLUSION: The best results were obtained with the group with autogenous bone and Bio-Oss. filling used in conjunction with a membrane.

Histologic Evaluation Of Peri-Implant Defects With Particulate Dentin-Plaster Of Paris Combination And Bioresorbable Membrane Barriers

The Effect of Bioresorbable Membrane on the Bone Regeneration of Streptozotocin Induced Diabetic Rats / 대한치주과학회지

The purpose of this study is to evaluate the effects of bioresorbable membranes in guided bone regeneration of streptozotocin induced diabetic rats. 50 Sprague-Dawley rats were randomly categorized into 4 groups: Group 1 & 2 had 10 normal rats each and group 3 & 4 included 15 streptozotocin induced diabetic rats each. Defect measuring 7mm in diameter was formed on every rat calvarium. No membrane was used in groups 1 & 3 and membranes were used in groups 2 & 4. The rates were sacrificed at 2 and 4 weeks after defect formation. Routine histological specimens were prepared. Masson-trichrome and HE stain were done before light microscopy. Guided regenerative potential was evaluated by measuring the amount of new bone formation in the calvarial defect by histomorphometry. Following results were obtained. 1.New bone formation in the diabetic groups was significantly less that than in the normal groups regardless of membrane use(p <0.05). 2.In the comparison of new bone formation in the normal groups, membrane group showed significantly more bone formation(p <0.1). 3.When the amount of new bone formation was compared in the diabetic groups, more bone was formed in the membrane groups but the difference was not statistically significant. 4.In the normal groups the amount of new bone formation was significantly greater at 4 weeks compared to that at 2 weeks(p <0.05) but amount of bone regeneration at 4 weeks was not significantly greater than that at 2 weeks in both diabetic groups.

Development of moldable bone regenerating therapeutics using partially purified porcine bone morphogenetic protein and bioresorbable polymer

The purpose of this study was to develop an osteogenic, biodegradable material using polymer and BMP. It was designed to have structural function and be moldable, for the reconstruction of load bearing areas and deformities of various configurations. Bone apatite was added to Poly(L-lactide)(PLLA) and made porous for osteoconductability and ease of BMP loading. The materials, with or without BMP purified from porcine bone matrix, were evaluated in cranial bone defect models in rats for biocompatibility and bone regeneration capability. The following results were obtained: The PLLA-BMP material with BMP added to the polymer showed 30% healing of cranial bone defects in rats during the 2 weeks to 3 months period of observation. The moldable PLLA agent without BMP also showed 25% bone healing capacity. Although new bone formation was incomplete in the critical size defect of rat cranium, it can be concluded that the unique moldability of those agents makes them useful for the reconstruction of various bone defects and maxillofacial deformities.