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Formation of mucus plug within a stent. The inability to clear secretions due to the obstruction leads to the development of a pneumonia.
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It has been 30 years since the first commercial three-dimensional (3D) printer was available on market. The technological advancement of 3D printing has far exceeded its implementation in medicine. The application of 3D printing technology has the potential of playing a major role within interventional pulmonology; specifically, in the management o...
Context in source publication
Context 1
... can achieve airway patency and maintain ventilation of the lung parenchyma for a time. Without a precise fit into the area, complications can arise with either type of stent: plugging with or without concurrent infection (Figure 1), metal fatigue leading to fracture (Figure 2), migration (Figure 3), formation of granulation tissue (Figure 4), and mucosal incorporation with possible erosion and perforation ( Figure 5) (7). Silicone stents and SEMS have individual advantages and disadvantages ( Table 1). ...
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infection among healthc...
Citations
... While various biodegradable airway stents are currently assessed in experimental studies, some have already been in clinical use [11][12][13][14]. To minimize the risk of migration, there are approaches to offer patient-tailored stents for providing ideal fit and therefore also improve long-term tolerance [15,16]. Furthermore, there is ongoing intensive research on airway stents offering drug-elution that can prevent and/or treat secondary complications like granulation tissue, infection or inflammatory reaction to the foreign body. ...
To date, several types of airway stents are available to treat central airway obstructions. However, the ideal stent that can overcome anatomical, mechanical and microbiological issues is still awaited. In addition, therapeutic effect and self-elimination of these stents are desirable properties, which pose an additional challenge for development and manufacturing. We aimed to create a prototype bioresorbable tracheal stent with acceptable clinical tolerance, fit and biocompatibility, that could be tested in a rabbit model and in the future be further optimized to enable drug-elution and ensure local therapeutic effect. Twenty-one New Zealand White Rabbits received five different types of bioresorbable tracheal stents, 3D-printed from poly(D,L-lactide-co-ε-caprolactone) metacrylates. Various configurations were tested for their functionality and improved until the best performing prototype could undergo detailed in vivo assessment, regarding clinical tolerance, migration and biocompatibility. Previously tested types of 3D printed stents in our preliminary study required improvement due to several problems, mainly related to breakage, unreliable stability and/or migration within the trachea. Abandoned or refined pre-prototypes were not analyzed in a comparative way. The final best performing prototype stent (GSP2 (Group Stent Prototype 2), n = 8) allowed a transoral application mode and showed good clinical tolerance, minimal migration and acceptable biocompatibility. The good performance of stent type GSP2 was attributed to the helix-shaped surface structure, which was therefore regarded as a key-feature. This prototype stent offers the possibility for further research in a large animal model to confirm the promising data and assess other properties such as bioresorption.
... They are also associated with theoretically less traumatic removal due to less ingrowth. And recently customized (both 3D printed and impromptu hand customized) silicone stents have been used in the management of transplant patients with AC with generally positive outcomes [39,42,43•] (see Fig. 1). Because of a better fit, there may be advantages to custom silicone stent use, but research on outcomes is currently lacking. ...
Purpose of Review
This review describes the pathophysiology and risk factors associated with airway complications post lung transplant. We discuss the different types of airway complications (AC) and their management based on recent literature reviews and institutional experience.
Recent Findings
AC are now less frequent due to improvements in procurement, surgical techniques, and post-operative management of lung transplant. Risk factors for AC are well described and involve both donor and recipient factors. The management of airway complications is not universally agreed upon, and data regarding the efficacy of different modalities is limited.
Summary
Airway management requires a multidisciplinary approach between interventional pulmonary, lung transplant, and occasionally surgical teams. With small or limited airway defects, we advocate for conservative medical management. For more extensive airway complications, advanced bronchoscopic techniques may be utilized with good outcomes. Research is needed to validate the efficacy of customized silica stents for airway complications.
... Currently available stents may be silicone, stainless steel, polymer, nitinol, tygon, tantalum, cobalt-based alloy, or hybrid of materials [1]. Despite this, preconfigured airway stents are seldom ideal due to the dynamic nature of inspiration and expiration and the distorted airway anatomy in this population of patients [2,3]. This has led to substantial efforts to develop custom stents for patients with complex airway diseases that may be more biocompatible and thus reduce complications [2,4]. ...
Purpose of Review
In this review, we summarize the evolution of airway stents through the decades and address the various existing stent types along with some investigational stents, and the available data supporting their use. We also briefly discuss the most common complications, the process of removal, and controversies regarding follow-up.
Recent Findings
Stent technology continues to evolve in an ongoing effort to develop better stents with easier placement or removal, sustained clinical benefit, and the least number of complications. These improvements have allowed for the expansion of stent use from primarily palliation in malignant airway diseases to viable therapies for benign conditions including malacia, fistulas, and post-intubation tracheal stenosis.
Summary
Airway stents can provide prompt and sustained relief of symptoms for a variety of tracheobronchial diseases. Airway stents have undergone significant advancements in the past three decades, starting with single material stents to hybrid stents and now towards more personalized stents.
... 3D printing plays a vital role in unraveling this complexity, enhancing our comprehension of lung function and diseases. [45][46][47][48][49] Several reports have demonstrated the utility of 3D printing in various respiratoryrelated issues, including medical education, 45,50 airway stent placement, 49,51 development of airway adaptors, 52 endoscope preplanning, 53 evaluation of inhalable medicines, 54,55 and mitigating the shortage of medical supplies during the coronavirus disease 2019 pandemic. 56-60 3D printing is primarily utilized in medical education, with a particular emphasis on anatomy study and simulation training, representing the 2 major areas of focus. ...
Background:
Three-dimensional (3D)-printed models are cost-effective and can be customized by trainers. This study designed a 3D-printed airway suction simulator for use by respiratory therapy (RT) students. The objective was to demonstrate the cost-effectiveness and application of 3D-printed models in respiratory care training, aiming to enhance the educational experience for RT students.
Methods:
This study developed a 3D-printed airway suction simulator that was cost-effective. A randomized controlled trial was conducted involving RT students to compare effectiveness in a 3D-model group and a control group. Skill assessments and written examinations were used to evaluate the participants' knowledge and skills.
Results:
A total of 38 second-year RT students were randomly assigned to either the 3D-model group (n = 19) or the control group (n = 19). One participant in the 3D-model group was lost to follow-up during the planned direct observation of procedural skills (DOPS) assessment and satisfaction questionnaire completion. The posttest written examination scores were significantly higher in the 3D-model group than in the control group (100% vs 80%, P = .02). The scores from the DOPS and satisfaction questionnaire were comparable in the 2 groups.
Conclusions:
This study demonstrated that 3D printing can be used to create a safe and cost-effective airway suction simulator for use by RT students, with potential to enhance training methods. Further research is necessary.
... 6 These have proven to be modifiable prior to implantation, which addresses some of the mechanical issues with 'fit'. 7 However, challenges include infection, migration, mucus plugging, and granulation, necessitation of lifelong management, and recurrent stent TherapeuTic advances in respiratory disease replacement [8][9][10][11][12][13][14][15][16][17] Many variables in stent design have been altered over the years, ranging from basic materials, coverings, size, shape, to deployment and other properties. ...
... We have been working on patient-specific (PS) airway stents for a number of years. 3,13 An airway stent remains an option of last resort because of its many challenges. The purpose of this article was to evaluate a methodology using software to look at the stents' fit within the airway by visual assessment. ...
Managing complex benign airway disease is a major challenge in interventional pulmonology. With the introduction of additive manufacturing in the medical field, patient-specific (PS) implants are an innovate prospect for airway management. Historically, stents were oversized to resist migration. However, the optimal degree and impact of stent oversizing remains unclear. The ability to design stents based on computed tomography (CT) invites opportunity to understand sizing. Here, we report a novel three-dimensional (3D) image reconstruction tool to quantify fit repeatedly over time. Analysis of CT imaging before and after successive stent implants in a single patient with different areas of stenosis and malacia was done. Nine PS airway stents over 4 years (five left mainstem and four right mainstem) were studied. The distance between the airway model and stent was calculated. The CT images were correlated to stent designs in CloudCompare software (v2.10-alpha) for novel analysis. Heat map was exported depicting the distances between the airway and the stent to the clinician's prescribed stent model. Corresponding histograms containing distances, mean, and standard deviation were reported. It is possible to measure stent fit based on heat map quantification on patient imaging. Observation of the airway over time and stent change suggests that the airway became more open over time requiring increased stent diameters. The ability to design and measure stent fit over time can help quantify the utility and impact of PS silicone airway stent. The airway appears to display plasticity such that there is notable change in stent prescription over time.
... Because of the intricate features of the tracheobronchial anatomy, Threedimensional printing (3DP) technology is perfect for creating airway prostheses to treat difficult conditions. With the help of years of research and development, it is now possible to produce a patient-specific stent [19][20][21][22]. A patient-specific stent may help decrease risks, shorten healing time, and enhance patients' quality of life while alleviating symptoms and avoiding the need for additional bronchoscopies. ...
A central goal of an airway stent is to restore patency by preventing restenosis, holding the tracheobronchial wall, or occluding fistulas. Complications with stents, however, are frequent and can have grave repercussions. Stents are therefore viewed as a last resort in cases where other forms of treatment are ineffective. Furthermore, it is common for people with complex airways to have airway stents that do not fit them well, which can result in several complications. Three-dimensional printing technology was developed at the turn of the 20th century. It has been employed in a variety of applications and has transformed healthcare. This technology has mainly been employed in respiratory medicine to develop three-dimensional models of the airways and to make airway splints and prostheses to treat central airway diseases. In the past ten years, it has transformed and advanced personalized medicine, enabling the creation of patient-specific stents for people with complex airway diseases. Three-dimensional printing might be used to create a patient-specific stent that would lessen risks, enhance the quality of life, and eliminate the need for additional procedures. This chapter discusses the most recent developments in three-dimensional printing technology, how they are being used to create airway prostheses to treat complex airway illnesses and the current body of research that supports their use.
... Common adverse events observed with CAS were less frequent with 3DPSS, and a significant increase in the lifespan of the patient-specific stents was observed (100,104) ( Figure 4). Moreover, RB remains an important and relevant tool for these recent stent innovations (100,105,106). ...
German laryngologist Gustav Killian performed the first "Direkte Bronchoskopie" using a rigid bronchoscope to extract a foreign airway body from the right main bronchus over a hundred years ago, transforming the practice of respiratory medicine. The procedure instantaneously became popular throughout the world. Chevalier Jackson Sr from the United States further advanced the instrument, technique, safety, and application. In the 1960s, Professors Harold H. Hopkins and N.S. Kapany introduced optical rods as well as fiberoptics that led Karl Storz to develop the cold light system improving endoluminal illumination, achievements that ushered in the modern era of flexible endoscopy. Several diagnostic and therapeutic procedures became possible such as transbronchial needle biopsy, transbronchial lung biopsy, airway electrosurgery, or cryotherapy. Dr. Jean-François Dumon from France advanced the use of Nd-YAG laser in the endobronchial tree and created the dedicated Dumon silicone stent introducing the whole new field of interventional pulmonology (IP). This major milestone revitalized interest in rigid bronchoscopy (RB). Now, advancements are being made in stenting, instrumentation, and education. RB robotic technology advancements are currently anticipated and can potentially revolutionize the practice of pulmonary medicine. In this review, we describe some of the most substantial advances related to RB from its beginning to the modern era.
... Customised patient-specific stents Customised patient-specific printed airway stents are believed to have a better stent-airway conformation than pre-manufactured airway stents in generic sizes [77]. The stent is created from a mould derived from the patient's airway. ...
Endobronchial stenting is an important aspect of the practice of interventional pulmonology. The most common indication for stenting is the management of clinically significant airway stenosis. The list of endobronchial stents available on the market continues to grow. More recently, patient-specific 3D-printed airway stents have been approved for use. Airway stenting should be considered only when all other options have been exhausted. Due to the environment of the airways and the stent-airway wall interactions, stent-related complications are common. Although stents can be placed in various clinical scenarios, they should only be placed in scenarios with proven clinical benefit. The unwarranted placement of a stent can expose the patient to complications with little or no clinical benefit. This article reviews and outlines the key principles of endobronchial stenting and important clinical scenarios in which stenting should be avoided.
... The complex characteristics of tracheobronchial anatomy make the three-dimensional (3D)-printing technology ideal for developing airway prostheses to treat complex diseases. Through years of investigation and advancement, it is now feasible to manufacture a patient-specific stent using this technology (19)(20)(21)(22). A patient-specific stent may help minimize complications, decrease procedure time, and improve patients' quality of life while reducing symptoms and the need for repeated procedures. ...
The primary function of an airway stent is to reestablish patency, impeding restenosis, supporting the tracheobronchial wall, or occluding fistulas. But stent-related complications are prevalent and can have devastating consequences. For this reason, stents are considered a last resort when there are no alternatives in treatment. Additionally, commercially available airway stents often poorly fit patients with complex airways, and they can cause various complications. At the end of the 20th century, three-dimensional (3D) printing technology was created. It has been transformative in healthcare and has been used in several applications. One of its first utilizations was the anatomical modeling of body structures that helps preoperative planning. In respiratory medicine, this technology has been essentially used in central airway diseases to produce 3D airway models and to create airway splints and prostheses. In the last decade, it has led to a transformation and allowed progress in personalized medicine, making patient-specific stents for individuals with complex airway problems. A patient-specific stent using 3D printing may minimize complications, improve quality of life, and reduce the need for repeated procedures. This review describes the recent advances in 3D printing technology, its use for developing airway prostheses to treat complex airway diseases, and the current evidence that supports its use.
... It has been established that additive manufacturing processes carry a high degree of customizability but, unfortunately, there is still some variability, which challenges meeting regulatory standards and quality assurance of personalized medical devices (20). Nevertheless, Willemsen et al. (19) reported a study showing that additive manufacturing can be a reality in a hospital setting, if the needed requirements are met, intending to motivate physicians to treat unique . ...
Background/aims
Combination products are therapeutic and/or diagnostic products that can combine drugs and medical devices and which increasing complexity has raised new regulatory framework challenges. To reach the market, a combination product must be classified based on the principal mode of action (PMOA). However, research and technological progress has been leading to the development of novel combination products with no clearly defined PMOA, emphasizing the lack of a systematization process, thus challenging the correct classification of these products. To illustrate the regulatory challenge, two case studies are discussed: innovative combination products with PMOA that can change due to an external stimulus, specifically custom-made 3D-printed scaffolds with incorporated medicinal substances.
Methods
Data was collected through computational search engines, regulatory agencies and equally relevant associations. The analysis of the data resulted on this state-of-the-art review, a description of the decision-making process by the regulatory authorities, and case studies analysis that culminated in the proposal of a decision-tree scheme.
Findings
Current regulations do not fully address complex combination products namely personalized 3D-printed scaffolds. Two merged regulatory approaches are suggested along with the schematization of the rational assisted by a decision-tree tool.
Conclusion
Combination products have become increasingly sophisticated, which has furthered the need to develop multidisciplinary collaborations within the health sector to adapt to these innovative healthcare solutions as well as with regulators to overcome the challenges posed for their classification.
