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Brooks KA, Lai AY, Tucker SJ, Ramaraju H, Verga A, Shashidharan S, Maher KO, Simon DM, Hollister SJ, Landry AM, Goudy SL. External airway splint placement for severe pediatric tracheobronchomalacia. Int J Pediatr Otorhinolaryngol 2023; 169:111559. [PMID: 37126976 DOI: 10.1016/j.ijporl.2023.111559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Revised: 03/31/2023] [Accepted: 04/17/2023] [Indexed: 05/03/2023]
Abstract
OBJECTIVE To present external airway splinting with bioabsorbable airway supportive devices (ASD) for severe, life-threatening cases of pediatric tracheomalacia (TM) or tracheobronchomalacia (TBM). METHODS A retrospective cohort was performed for 5 pediatric patients with severe TM or TBM who underwent ASD placement. Devices were designed and 3D-printed from a bioabsorbable material, polycaprolactone (PCL). Pre-operative planning included 3-dimensional airway modeling of tracheal collapse and tracheal suture placement using nonlinear finite element (FE) methods. Pre-operative modeling revealed that triads along the ASD open edges and center were the most effective suture locations for optimizing airway patency. Pediatric cardiothoracic surgery and otolaryngology applied the ASDs by suspending the trachea to the ASD with synchronous bronchoscopy. Respiratory needs were trended for all cases. Data from pediatric patients with tracheostomy and diagnosis of TM or TBM, but without ASD, were included for discussion. RESULTS Five patients (2 Females, 3 Males, ages 2-9 months at time of ASD) were included. Three patients were unable to wean from respiratory support after vascular ring division; all three weaned to room air post-ASD. Two patients received tracheostomies prior to ASD placement, but continued to experience apparent life-threatening events (ALTE) and required ventilation with supraphysiologic ventilator settings. One patient weaned respiratory support successfully after ASD placement. The last patient died post-ASD due to significant respiratory co-morbidity. CONCLUSION ASD can significantly benefit patients with severe, unrelenting tracheomalacia or tracheobronchomalacia. Proper multidisciplinary case deliberation and selection are key to success with ASD. Pre-operative airway modeling allows proper suture placement to optimally address the underlying airway collapse.
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Affiliation(s)
- Kaitlyn A Brooks
- Department of Otolaryngology- Head and Neck Surgery, Children's Healthcare of Atlanta, Emory University School of Medicine, Atlanta, GA, USA.
| | - Annie Y Lai
- Scheller College of Business, Georgia Institute of Technology, Atlanta, GA, USA; Pediatric Intensive Care Unit, Children's Healthcare of Atlanta - Egleston, Atlanta, GA, USA
| | - Sarah J Tucker
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Harsha Ramaraju
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Adam Verga
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Subhadra Shashidharan
- Division of Cardiothoracic Surgery, Department of Surgery, Children's Healthcare of Atlanta, Emory University School of Medicine, Atlanta, GA, USA
| | - Kevin O Maher
- Division of Cardiology, Pediatric Cardiology, Children's Healthcare of Atlanta Heart Center, Emory University School of Medicine Department of Pediatrics, Atlanta, GA, USA
| | - Dawn M Simon
- Division of Pulmonology, Pediatric Pulmonology, Children's Healthcare of Atlanta, Emory University School of Medicine Department of Pediatrics, Atlanta, GA, USA
| | - Scott J Hollister
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - April M Landry
- Department of Otolaryngology- Head and Neck Surgery, Children's Healthcare of Atlanta, Emory University School of Medicine, Atlanta, GA, USA
| | - Steven L Goudy
- Department of Otolaryngology- Head and Neck Surgery, Children's Healthcare of Atlanta, Emory University School of Medicine, Atlanta, GA, USA
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Biaxial mechanical properties of the bronchial tree: Characterization of elasticity, extensibility, and energetics, including the effect of strain rate and preconditioning. Acta Biomater 2023; 155:410-422. [PMID: 36328122 DOI: 10.1016/j.actbio.2022.10.047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 10/18/2022] [Accepted: 10/21/2022] [Indexed: 11/05/2022]
Abstract
Distal airways commonly obstruct in lung disease and despite their importance, their mechanical properties are vastly underexplored. The lack of bronchial experiments restricts current airway models to either assume rigid structures, or extrapolate the material properties of the trachea to represent the small airways. Furthermore, past works are exclusively limited to uniaxial testing; investigating the multidirectional tensile loads of both the proximal and distal pulmonary airways is long overdue. Here we present comprehensive mechanical and viscoelastic properties of the porcine airway tree, including the trachea, trachealis muscle, large bronchi, and small bronchi, via measures of elasticity, extensibility, and energetics to explore regional and directional dependencies, cross-examining strain rate and preconditioning effects using planar equibiaxial tensile tests for the first time. We find bronchial regions are notably heterogeneous, where the trachea exhibits greater stiffness, energy loss, and preconditioning sensitivity than the smaller airways. Interestingly, the trachealis muscle is similar to the distal bronchi, despite being anatomically located adjacent to the proximal ring. Tissues are anisotropic and axially stiffer under initial loading, losing more energy with greater stress relaxation circumferentially. Strain rate dependency is also noted, where tissues are more energetically efficient at the faster strain rate, likely attributable to the microstructure. Findings highlight assumptions of homogeneity and isotropy are inadequate, and enable the improvement of aerosol flow and dynamic airway deformation computational predictive models. These results provide much needed fundamental material properties for future explorations contrasting healthy versus diseased pulmonary airway mechanics to better understand the relationship between structure and lung function. STATEMENT OF SIGNIFICANCE: We present comprehensive multiaxial mechanical tensile experiments of the proximal and distal airways via measures of maximum stress, initial and ultimate moduli, strain and stress transitions, hysteresis, energy loss, and stress relaxation, and further assess preconditioning and strain rate dependencies to examine the relationship between lung function and structure. The mechanical response of the bronchial tree demonstrates significant anisotropy and heterogeneity, even within the tracheal ring, and emphasizes that contrary to past studies, the behavior of the proximal airways cannot be extended to distal bronchial tree analyses. Establishing these material properties is critical to advancing our understanding of airway function and in developing accurate computational simulations to help diagnose and monitor pulmonary diseases.
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Ramaraju H, Landry AM, Sashidharan S, Shetty A, Crotts SJ, Maher KO, Goudy SL, Hollister SJ. Clinical grade manufacture of 3D printed patient specific biodegradable devices for pediatric airway support. Biomaterials 2022; 289:121702. [PMID: 36041362 DOI: 10.1016/j.biomaterials.2022.121702] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 07/10/2022] [Accepted: 07/24/2022] [Indexed: 01/01/2023]
Abstract
Implantable patient-specific devices are the next frontier of personalized medicine, positioned to improve the quality of care across multiple clinical disciplines. Translation of patient-specific devices requires time- and cost-effective processes to design, verify and validate in adherence to FDA guidance for medical device manufacture. In this study, we present a generalized strategy for selective laser sintering (SLS) of patient-specific medical devices following the prescribed guidance for additive manufacturing of medical devices issued by the FDA in 2018. We contextualize this process for manufacturing an Airway Support Device, a life-saving tracheal and bronchial implant restoring airway patency for pediatric patients diagnosed with tracheobronchomalacia and exhibiting partial or complete airway collapse. The process covers image-based modeling, design inputs, design verification, material inputs and verification, device verification, and device validation, including clinical results. We demonstrate how design and material assessment lead to verified Airway Support Devices that achieve desired airway patency and reduction in required Positive End-Expiratory Pressure (PEEP) after patient implantation. We propose this process as a template for general quality control of patient-specific, 3D printed implants.
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Affiliation(s)
- Harsha Ramaraju
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA.
| | - April M Landry
- Department of Otolaryngology-Head and Neck Surgery, Children's Healthcare of Atlanta, Emory University, Atlanta, GA, USA
| | - Subhadra Sashidharan
- Division of Cardiothoracic Surgery, Department of Surgery, Children's Healthcare of Atlanta, Emory University School of Medicine, Atlanta, GA, USA
| | | | - Sarah J Crotts
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Kevin O Maher
- Division of Cardiology, Pediatric Cardiology, Children's Healthcare of Atlanta, Atlanta, GA, 30322, USA; Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Steven L Goudy
- Division of Pediatric Otolaryngology, Department of Otolaryngology-Head and Neck Surgery, Children's Healthcare of Atlanta, Emory University, Atlanta, GA, USA
| | - Scott J Hollister
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA.
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Molecular Mechanisms and Physiological Changes behind Benign Tracheal and Subglottic Stenosis in Adults. Int J Mol Sci 2022; 23:ijms23052421. [PMID: 35269565 PMCID: PMC8910114 DOI: 10.3390/ijms23052421] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 02/16/2022] [Accepted: 02/21/2022] [Indexed: 02/06/2023] Open
Abstract
Laryngotracheal stenosis (LTS) is a complex and heterogeneous disease whose pathogenesis remains unclear. LTS is considered to be the result of aberrant wound-healing process that leads to fibrotic scarring, originating from different aetiology. Although iatrogenic aetiology is the main cause of subglottic or tracheal stenosis, also autoimmune and infectious diseases may be involved in causing LTS. Furthermore, fibrotic obstruction in the anatomic region under the glottis can also be diagnosed without apparent aetiology after a comprehensive workup; in this case, the pathological process is called idiopathic subglottic stenosis (iSGS). So far, the laryngotracheal scar resulting from airway injury due to different diseases was considered as inert tissue requiring surgical removal to restore airway patency. However, this assumption has recently been revised by regarding the tracheal scarring process as a fibroinflammatory event due to immunological alteration, similar to other fibrotic diseases. Recent acquisitions suggest that different factors, such as growth factors, cytokines, altered fibroblast function and genetic susceptibility, can all interact in a complex way leading to aberrant and fibrotic wound healing after an insult that acts as a trigger. However, also physiological derangement due to LTS could play a role in promoting dysregulated response to laryngo-tracheal mucosal injury, through biomechanical stress and mechanotransduction activation. The aim of this narrative review is to present the state-of-the-art knowledge regarding molecular mechanisms, as well as mechanical and physio-pathological features behind LTS.
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Bellia-Munzon G, Cieri P, Toselli L, Cuestas G, Doormann F, Gabaldón-Massé P, Rodriguez V, Bellia-Munzon P. Resorbable airway splint, stents, and 3D reconstruction and printing of the airway in tracheobronchomalacia. Semin Pediatr Surg 2021; 30:151063. [PMID: 34172216 DOI: 10.1016/j.sempedsurg.2021.151063] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Tracheobronchomalacia (TBM) is the most common tracheobronchial obstruction. Most cases are mild to moderate; therefore, they do not need surgical treatment. Severe tracheomalacia, however, represents a diagnostic and therapeutic challenge since they are very heterogeneous. In the armamentarium of resources for the treatment of dynamic airway collapse, splints and stents are two underused strategies and yet, they may represent the best alternative in selected cases. Lately, computed tomography 3D reconstruction of the airway has been used for the design of virtual models that can be 3D-printed for the creation of novel devices to address training, simulation, and biotechnological implants for refractory and severe airway malformations. This manuscript examines the role of resorbable stents, splints, and the 3D reconstruction and printing of the pediatric airway in tracheobronchomalacia.
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Affiliation(s)
- Gaston Bellia-Munzon
- Hospital General de Niños Pedro de Elizalde, Buenos Aires, Argentina.; Fundación Hospitalaria Mother and Child Medical Center, Buenos Aires, Argentina
| | - Patricio Cieri
- Hospital General de Niños Pedro de Elizalde, Buenos Aires, Argentina.; Fundación Hospitalaria Mother and Child Medical Center, Buenos Aires, Argentina..
| | - Luzia Toselli
- Fundación Hospitalaria Mother and Child Medical Center, Buenos Aires, Argentina
| | - Giselle Cuestas
- Hospital General de Niños Pedro de Elizalde, Buenos Aires, Argentina.; Fundación Hospitalaria Mother and Child Medical Center, Buenos Aires, Argentina
| | - Flavia Doormann
- Hospital General de Niños Pedro de Elizalde, Buenos Aires, Argentina.; Fundación Hospitalaria Mother and Child Medical Center, Buenos Aires, Argentina
| | - Paula Gabaldón-Massé
- Hospital General de Niños Pedro de Elizalde, Buenos Aires, Argentina.; Fundación Hospitalaria Mother and Child Medical Center, Buenos Aires, Argentina
| | - Verónica Rodriguez
- Hospital General de Niños Pedro de Elizalde, Buenos Aires, Argentina.; Fundación Hospitalaria Mother and Child Medical Center, Buenos Aires, Argentina
| | - Patricio Bellia-Munzon
- Hospital General de Niños Pedro de Elizalde, Buenos Aires, Argentina.; Fundación Hospitalaria Mother and Child Medical Center, Buenos Aires, Argentina
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Subramaniam DR, Oren L, Willging JP, Gutmark EJ. Evaluating the biomechanical characteristics of cuffed-tracheostomy tubes using finite element analysis. Comput Methods Biomech Biomed Engin 2021; 24:1595-1605. [PMID: 33761806 DOI: 10.1080/10255842.2021.1902511] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The objective of this study was to perform finite element analysis (FEA) of cuff inflation within an anatomically accurate model of an adult trachea in four different cuffed-tracheostomy tube designs. The leakage quantified by the distance between the cuff and trachea was largest for the Tracoe cuff and smallest for the Portex cuff. The smooth muscle stresses were greatest for the Portex and least for the Distal cuff, respectively. The proposed FEA model offers a promising approach to virtually evaluate the sealing efficacy of cuffed-tracheostomy tubes and the tracheal wall stresses induced by cuff inflation, prior to application.
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Affiliation(s)
| | - Liran Oren
- Department of Otolaryngology-Head and Neck Surgery, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - J Paul Willging
- Division of Pediatric Otolaryngology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Ephraim J Gutmark
- Department of Aerospace Engineering and Engineering Mechanics, University of Cincinnati, Cincinnati, OH, USA.,Department of Otolaryngology-Head and Neck Surgery, University of Cincinnati College of Medicine, Cincinnati, OH, USA
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7
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When to consider a posterolateral descending aortopexy in addition to a posterior tracheopexy for the surgical treatment of symptomatic tracheobronchomalacia. J Pediatr Surg 2020; 55:2682-2689. [PMID: 32444171 DOI: 10.1016/j.jpedsurg.2020.04.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 03/09/2020] [Accepted: 04/23/2020] [Indexed: 11/23/2022]
Abstract
PURPOSES The descending thoracic aorta typically crosses posterior to the left mainstem bronchus (LMSB). We sought to evaluate patient factors that may lead one to consider a posterolateral descending thoracic aortopexy (PLDA) in addition to a posterior tracheopexy (PT) in the surgical treatment of symptomatic tracheobronchomalacia (TBM) that involves the LMSB. METHODS Retrospective review of patients who underwent PT with or without PLDA between 2012 and 2017. Severity and extent of TBM were assessed using dynamic tracheobronchoscopy. Aortic positioning compared to the anterior border of the spine (ABS) at the level of the left mainstem bronchus was identified on computed tomography (CT). Factors associated with performing a PLDA were evaluated with logistic regression. RESULTS Of 188 patients who underwent a PT, 70 (37%) also had a PLDA performed. On multivariate analysis, >50% LMSB compression on bronchoscopy (OR 8.06, p < 0.001), >50% of the aortic diameter anterior to the ABS (OR 2.06, p = 0.05), and more recent year of surgery (OR 1.61, p = 0.003) were associated with performing a PLDA. CONCLUSION When performing a PT, a PLDA should be considered for patients who have >50% LMSB compression on dynamic bronchoscopy, and in those with a descending thoracic aorta located >50% anterior to the ABS. LEVEL OF EVIDENCE III TYPE OF STUDY: Retrospective comparative study.
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Wallis C, Alexopoulou E, Antón-Pacheco JL, Bhatt JM, Bush A, Chang AB, Charatsi AM, Coleman C, Depiazzi J, Douros K, Eber E, Everard M, Kantar A, Masters IB, Midulla F, Nenna R, Roebuck D, Snijders D, Priftis K. ERS statement on tracheomalacia and bronchomalacia in children. Eur Respir J 2019; 54:13993003.00382-2019. [PMID: 31320455 DOI: 10.1183/13993003.00382-2019] [Citation(s) in RCA: 87] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Accepted: 05/16/2019] [Indexed: 01/20/2023]
Abstract
Tracheomalacia and tracheobronchomalacia may be primary abnormalities of the large airways or associated with a wide variety of congenital and acquired conditions. The evidence on diagnosis, classification and management is scant. There is no universally accepted classification of severity. Clinical presentation includes early-onset stridor or fixed wheeze, recurrent infections, brassy cough and even near-death attacks, depending on the site and severity of the lesion. Diagnosis is usually made by flexible bronchoscopy in a free-breathing child but may also be shown by other dynamic imaging techniques such as low-contrast volume bronchography, computed tomography or magnetic resonance imaging. Lung function testing can provide supportive evidence but is not diagnostic. Management may be medical or surgical, depending on the nature and severity of the lesions, but the evidence base for any therapy is limited. While medical options that include bronchodilators, anti-muscarinic agents, mucolytics and antibiotics (as well as treatment of comorbidities and associated conditions) are used, there is currently little evidence for benefit. Chest physiotherapy is commonly prescribed, but the evidence base is poor. When symptoms are severe, surgical options include aortopexy or posterior tracheopexy, tracheal resection of short affected segments, internal stents and external airway splinting. If respiratory support is needed, continuous positive airway pressure is the most commonly used modality either via a face mask or tracheostomy. Parents of children with tracheobronchomalacia report diagnostic delays and anxieties about how to manage their child's condition, and want more information. There is a need for more research to establish an evidence base for malacia. This European Respiratory Society statement provides a review of the current literature to inform future study.
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Affiliation(s)
- Colin Wallis
- Respiratory Medicine Unit, Great Ormond Street Hospital for Children, London, UK
| | - Efthymia Alexopoulou
- 2nd Radiology Dept, National and Kapodistrian University of Athens, Attikon University Hospital, Athens, Greece
| | - Juan L Antón-Pacheco
- Pediatric Airway Unit and Pediatric Surgery Division, Universidad Complutense de Madrid, Madrid, Spain
| | - Jayesh M Bhatt
- Nottingham University Hospitals NHS Trust, Queen's Medical Centre, Nottingham, UK
| | - Andrew Bush
- Imperial College London and Royal Brompton and Harefield NHS Foundation Trust, London, UK
| | - Anne B Chang
- Dept of Respiratory and Sleep Medicine, Queensland Children's Hospital, Brisbane, Australia.,Centre for Children's Health Research, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia.,Child Health Division, Menzies School of Health Research, Charles Darwin University, Casuarina, Australia
| | | | | | - Julie Depiazzi
- Physiotherapy Dept, Perth Children's Hospital, Perth, Australia
| | - Konstantinos Douros
- Allergology and Pulmonology Unit, 3rd Paediatric Dept, National and Kapodistrian University of Athens, Athens, Greece
| | - Ernst Eber
- Division of Paediatric Pulmonology and Allergology, Dept of Paediatrics and Adolescent Medicine, Medical University of Graz, Graz, Austria
| | - Mark Everard
- Division of Paediatrics, University of Western Australia, Perth Children's Hospital, Perth, Australia
| | - Ahmed Kantar
- Pediatric Asthma and Cough Centre, Istituti Ospedalieri Bergamaschi, University and Research Hospitals, Bergamo, Italy
| | - Ian B Masters
- Dept of Respiratory and Sleep Medicine, Queensland Children's Hospital, Brisbane, Australia.,Centre for Children's Health Research, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia
| | - Fabio Midulla
- Dept of Paediatrics, "Sapienza" University of Rome, Rome, Italy
| | - Raffaella Nenna
- Dept of Paediatrics, "Sapienza" University of Rome, Rome, Italy.,Asthma and Airway Disease Research Center, University of Arizona, Tucson, AZ, USA
| | - Derek Roebuck
- Interventional Radiology Dept, Great Ormond Street Hospital, London, UK
| | - Deborah Snijders
- Dipartimento Salute della Donna e del Bambino, Università degli Studi di Padova, Padova, Italy
| | - Kostas Priftis
- Allergology and Pulmonology Unit, 3rd Paediatric Dept, National and Kapodistrian University of Athens, Athens, Greece
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Sul B, Altes T, Ruppert K, Qing K, Hariprasad DS, Morris M, Reifman J, Wallqvist A. In vivo dynamics of the tracheal airway and its influences on respiratory airflows. J Biomech Eng 2019; 141:2733770. [PMID: 31074759 DOI: 10.1115/1.4043723] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Indexed: 11/08/2022]
Abstract
Respiration is a dynamic process accompanied by morphological changes in the airways. Although deformation of large airways is expected to exacerbate pulmonary disease symptoms by obstructing airflow during increased minute ventilation, its quantitative effects on airflow characteristics remain unclear. Here, we used an exemplar case derived from in vivo dynamic imaging and examined the effects of tracheal deformation on airflow characteristics under different conditions. First, we measured tracheal deformation profiles of a healthy lung using magnetic resonance imaging during forced exhalation, which we simulated to characterize subject-specific airflow patterns. Subsequently, for both inhalation and exhalation, we compared the airflows when the maximal deformation in tracheal cross-sectional area was 0% (rigid), 33% (mild), 50% (moderate), or 75% (severe). We quantified differences in airflow patterns between deformable and rigid airways by computing the correlation coefficients (R) and the root-mean-square of differences (Drms) between their velocity contours. For both inhalation and exhalation, airflow patterns were similar in all branches between the rigid and mild conditions (R > 0.9; Drms < 32%). However, airflow characteristics in the moderate and severe conditions differed markedly from those in the rigid and mild conditions in all lung branches, particularly for inhalation (moderate: R > 0.1, Drms < 76%; severe: R > 0.2, Drms < 96%). Our exemplar case supports the use of a rigid airway assumption to compute flows for mild deformation. For moderate or severe deformation, however, dynamic contraction should be considered, especially during inhalation, to accurately predict airflow and elucidate the underlying pulmonary pathology.
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Affiliation(s)
- Bora Sul
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, Maryland; Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Materiel Command, Fort Detrick, Maryland
| | - Talissa Altes
- Department of Radiology, University of Missouri, Columbia, Missouri
| | - Kai Ruppert
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Kun Qing
- Department of Radiology, University of Virginia, Charlottesville, Virginia
| | - Daniel S Hariprasad
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, Maryland; Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Materiel Command, Fort Detrick, Maryland
| | - Michael Morris
- Graduate Medical Education, Brooke Army Medical Center, Joint Base San Antonio Fort Sam Houston, Texas
| | - Jaques Reifman
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Materiel Command, Fort Detrick, Maryland
| | - Anders Wallqvist
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Materiel Command, Fort Detrick, Maryland
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