This study presents a combined experimental and numerical investigation of fiber transport and deposition in a realistic model of the female respiratory tract, extending to the seventh generation of branching. Numerical simulations were performed using the Euler-Lagrange Euler-Rotation (ELER) method, an efficient alternative to conventional Finite Volume Methods that benefits from explicit formulation and vast scalability, enabling fast parallelization on high-performance clusters. The ELER method was coupled with the Lattice Boltzmann Method (LBM) to simulate fiber dynamics under a realistic inspiratory flow profile. Experimental validation was conducted using an identical physical airway replica. The results demonstrated good agreement between simulations and experiments in the upper airways and trachea, with some discrepancies in the bifurcations, likely owing to the challenges of modeling complex turbulent flow with ELER. This method is more accurate than corresponding effective diameter simulations. Deposition patterns were analyzed as a function of fiber dimensions, revealing higher accuracy of the ELER method for smaller particles and confirming the tendency of higher aspect ratio fibers to penetrate deeper into the lungs. The orientation-dependent deposition mechanism was deployed, underscoring the importance of solving the actual orientations of the fibers. While advancing our understanding of fiber transport in female airways, the findings also reveal limitations in current numerical techniques, particularly in bifurcations. This study emphasizes the distinct behavior of fibrous versus spherical particles, with fibers exhibiting a greater propensity to reach deeper lung regions, which has significant implications for inhalation toxicology and drug delivery.
- MeSH
- Administration, Inhalation MeSH
- Models, Biological * MeSH
- Respiratory System * MeSH
- Humans MeSH
- Lung MeSH
- Computer Simulation MeSH
- Trachea * physiology MeSH
- Check Tag
- Humans MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
Ageneze trachey je extrémně vzácná vrozená vývojová vada s vysokou mortalitou, která bývá často spojena s dalšími vrozenými vadami. Prenatálně je obtížně diagnostikovatelná a projevuje se po porodu rozvojem závažné dechové tísně, často vyžadujícím kardiopulmonální resuscitaci s urgentním zajištěním dýchacích cest. Při podezření na tuto diagnózu je možným krátkodobým řešením intubace do jícnu, ovšem za předpokládané přítomnosti tracheoči bronchoezofageální píštěle. Potvrzení diagnózy by mělo proběhnout za přítomnosti dětského ORL lékaře na specializovaném pracovišti, často ovšem ke stanovení diagnózy dochází až post mortem. Autoři prezentují případ těžce nedonošeného novorozence z nesledované gravidity s postnatálním respiračním selháním na základě ageneze trachey s tracheoezofageální píštělí.
Tracheal agenesis is an extremely rare congenital malformation with high mortality rate that is often associated with other congenital malformations. It is a defect that is difficult to diagnose prenatally with the postpartum development of severe respiratory distress syndrome, usually requiring cardiopulmonary resuscitation with urgent airway management. If this diagnosis is suspected, intubation into the esophagus is a possible short-term solution, however, only if a tracheo or bronchoesophageal fistula is present. Confirmation of the diagnosis should take place in the presence of a pediatric otorinolaryngologist at a specialized unit, but the diagnosis is often established post mortem. The authors present a case of a severely premature newborn from an unmonitored pregnancy with postnatal respiratory failure based on a tracheal agenesis with tracheoesophageal fistula.
- MeSH
- Respiratory System Abnormalities * diagnosis classification pathology therapy MeSH
- Fatal Outcome MeSH
- Humans MeSH
- Infant, Extremely Premature MeSH
- Infant, Newborn MeSH
- Autopsy MeSH
- Postnatal Care MeSH
- Trachea * abnormalities MeSH
- Tracheoesophageal Fistula etiology MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Infant, Newborn MeSH
- Publication type
- Case Reports MeSH
In 2020, there were numerous cases in Kazakhstan with clinical symptoms of COVID-19 but negative PCR results in nasopharyngeal and oropharyngeal swabs. The diagnosis was confirmed clinically and by CT scans (computed tomography). The problem with such negative PCR results for SARS-CoV-2 infection confirmation still exists and indicates the need to confirm the diagnosis in the bronchoalveolar lavage in such cases. There is also a lack of information about confirmation of SARS-CoV-2 infection in deceased patients. In this study, various tissue materials, including lungs, bronchi, and trachea, were examined from eight patients who died, presumably from SARS-CoV-2 infection, between 2020 and 2022. Naso/oropharyngeal swabs taken from these patients in hospitals tested PCR negative for SARS-CoV-2. This study presents a modified RNA isolation method based on a comparison of the most used methods for RNA isolation in laboratories: QIAamp Viral RNA Mini Kit and TRIzol-based method. This modified nucleic acid extraction protocol can be used to confirm SARS-CoV-2 infection by RT-qPCR in the tissues of deceased patients in disputed cases. RT-qPCR with RNA of SARS-CoV-2 re-extracted with such method from post-mortem tissues that were stored at -80 °C for more than 32 months still demonstrated high-yielding positive results.
- MeSH
- COVID-19 * virology diagnosis genetics MeSH
- Adult MeSH
- Real-Time Polymerase Chain Reaction methods MeSH
- Middle Aged MeSH
- Humans MeSH
- Nasopharynx virology MeSH
- Autopsy * methods MeSH
- Lung virology pathology diagnostic imaging MeSH
- RNA, Viral * genetics analysis MeSH
- SARS-CoV-2 * genetics MeSH
- Aged MeSH
- COVID-19 Nucleic Acid Testing methods MeSH
- Trachea virology pathology diagnostic imaging MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
We present a case of a preterm neonate with a type IV laryngo-tracheo-oesophageal cleft, an uncommon congenital malformation, resulting from the failure of separation of the trachea and the oesophagus during fetal development, often associated with other deformities as well. Data in the literature shows that the long-term morbidity from the entity has declined over the last decades, even though prognosis remains unfavourable for types III and IV. This report emphasizes the complex issues neonatologists are faced with, when treating neonates with this rare disorder in the first days of life, what will raise suspicion of this rare medical entity, and that direct laryngoscopy/bronchoscopy finally depicts the exact extension of the medical condition. At the same time extensive evaluation for coexisting congenital anomalies should be performed. For all the above reasons, these neonates should be treated in specialized tertiary pediatric centers for multidisciplinary prompt management, which may improve, the outcome.
- MeSH
- Child MeSH
- Esophagus diagnostic imaging surgery abnormalities MeSH
- Laryngoscopy MeSH
- Larynx * diagnostic imaging surgery abnormalities MeSH
- Humans MeSH
- Infant, Newborn MeSH
- Trachea diagnostic imaging surgery abnormalities MeSH
- Congenital Abnormalities * MeSH
- Check Tag
- Child MeSH
- Humans MeSH
- Infant, Newborn MeSH
- Publication type
- Journal Article MeSH
- Case Reports MeSH
- Review MeSH
BACKGROUND: Biodegradable (BD) stents made from polydioxanone have been used only in human airways. These stents combine the advantages of classical tracheal stents, and fewer side effects are expected due to their biocompatibility and their time-limited presence in airways. However, new clinical consequences have arisen. Here, the authors share their experiences with BD stents for tracheal indications, focusing on their safety and efficacy. METHODS: This was a retrospective review of a collected database of adult patients who underwent implantation of biodegradable tracheal stents between September 2013 and December 2022 at the Department of Respiratory Medicine of the 1st Faculty of Medicine in Prague and Thomayer University Hospital. The indications included functionally significant nonmalignant tracheal stenosis and tracheomalacia. Self-expandable, biodegradable, polydioxanone tracheal stents manufactured by ELLA-CS Ltd. (Hradec Kralove, Czech Republic) were implanted during rigid bronchoscopy under general anaesthesia. All patients were followed up in the department and were provided with the necessary care. The main efficacy and safety parameters and relationships were analysed using descriptive statistics and Fisher ́s exact, Wilcoxon and Kruskal‒Wallis tests. RESULTS: A total of 65 stents were implanted in 47 adult patients. During the first two months after implantation, when adequate function was expected, the stent was found to be effective in 26 out of 39 patients who completed this period (66.7%). The clinical effectiveness reached 89.7%, as early restenoses were mostly mild and necessitated treatment in only 4 patients. The frequencies of significant mucostasis, migration and granulation tissue growth were 2.6%, 7.5% and 23.1%, respectively, during this period. Thirty-four participants completed the half-year follow-up period after the first or second stent insertion, and some were followed up beyond this period. Poor control of symptoms, the development of restenosis and the need for interventions were characteristic of this period as the stents degraded. Twenty-two patients who experienced remodelling or stabilization of the tracheal lumen achieved a stent-free state. Seven patients underwent subsequent surgical treatment. CONCLUSIONS: BD stents are safe and provide adequate tracheal support until they begin to degrade. The use of BD stents necessitates close monitoring of patients and accurate treatment of possible restenosis. TRIAL REGISTRATION: Based on project NT14146 - Biodegradable stents in the management of the large airways (2013-2015, MZ0/NT), registered on May 1, 2013, in the Research and Development and Innovation Information System of the Czech Republic and at ClinicalTrials.gov (reg. no. NCT02620319, December 2, 2015).
- MeSH
- Bronchoscopy * MeSH
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Young Adult MeSH
- Polydioxanone MeSH
- Prosthesis Design MeSH
- Retrospective Studies MeSH
- Aged MeSH
- Tracheal Stenosis * surgery MeSH
- Stents * MeSH
- Trachea surgery MeSH
- Tracheomalacia surgery MeSH
- Absorbable Implants * MeSH
- Treatment Outcome MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Young Adult MeSH
- Male MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Czech Republic MeSH
- MeSH
- Pulmonary Surgical Procedures history methods instrumentation MeSH
- History, 20th Century MeSH
- Esophagus surgery MeSH
- Thoracic Surgery * history methods instrumentation MeSH
- Humans MeSH
- Minimally Invasive Surgical Procedures history methods MeSH
- Trachea surgery MeSH
- Lung Transplantation history MeSH
- Check Tag
- History, 20th Century MeSH
- Humans MeSH
- Publication type
- Historical Article MeSH
Liposomal carrier systems have emerged as a promising technology for pulmonary drug delivery. This study focuses on two selected liposomal systems, namely, dipalmitoylphosphatidylcholine stabilized by phosphatidic acid and cholesterol (DPPC-PA-Chol) and dipalmitoylphosphatidylcholine stabilized by polyethylene glycol and cholesterol (DPPC-PEG-Chol). First, the research investigates the stability of these liposomal systems during the atomization process using different kinds of nebulizers (air-jet, vibrating mesh, and ultrasonic). The study further explores the aerodynamic particle size distribution of the aerosol generated by the nebulizers. The nebulizer that demonstrated optimal stability and particle size was selected for more detailed investigation, including Andersen cascade impactor measurements, an assessment of the influence of flow rate and breathing profiles on aerosol particle size, and an in vitro deposition study on a realistic replica of the upper airways. The most suitable combination of a nebulizer and liposomal system was DPPC-PA-Chol nebulized by a Pari LC Sprint Star in terms of stability and particle size. The influence of the inspiration flow rate on the particle size was not very strong but was not negligible either (decrease of Dv50 by 1.34 μm with the flow rate increase from 8 to 60 L/min). A similar effect was observed for realistic transient inhalation. According to the in vitro deposition measurement, approximately 90% and 70% of the aerosol penetrated downstream of the trachea using the stationary flow rate and the realistic breathing profile, respectively. These data provide an image of the potential applicability of liposomal carrier systems for nebulizer therapy. Regional lung drug deposition is patient-specific; therefore, deposition results might vary for different airway geometries. However, deposition measurement with realistic boundary conditions (airway geometry, breathing profile) brings a more realistic image of the drug delivery by the selected technology. Our results show how much data from cascade impactor testing or estimates from the fine fraction concept differ from those of a more realistic case.
- MeSH
- 1,2-Dipalmitoylphosphatidylcholine MeSH
- Aerosols MeSH
- Administration, Inhalation MeSH
- Bronchodilator Agents * MeSH
- Cholesterol MeSH
- Equipment Design MeSH
- Drug Delivery Systems MeSH
- Humans MeSH
- Liposomes MeSH
- Nebulizers and Vaporizers MeSH
- Trachea * MeSH
- Particle Size MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- MeSH
- Esophagus injuries MeSH
- Intubation, Intratracheal * classification methods nursing MeSH
- Intubation classification methods MeSH
- Cannula classification MeSH
- Humans MeSH
- Infant, Newborn MeSH
- Carbon Dioxide analysis MeSH
- Trachea injuries MeSH
- Check Tag
- Humans MeSH
- Infant, Newborn MeSH
- Publication type
- Review MeSH
Komplexní sdělení o nádorech štítné žlázy, současných možnostech léčby karcinomu štítné žlázy v závislosti na jeho histologickém typu a rozsahu postižení, se zaměřením zejména na lokálně pokročilé a hraničně operabilní nálezy. Léčba této heterogenní skupiny nádorů vyžaduje většinou dlouhodobou a multidisciplinární spolupráci. Popis čtyř zajímavých kazuistik s obrazovou dokumentací, popisem průběhu léčby a posouzením invalidity. Rozbor a doporučené hodnocení procentního snížení pracovní schopnosti z pohledu posudkového lékaře u jednotlivých kazuistik a srovnání s reálnými posudky.
A complex report on thyroid tumors current treatment options for thyroid cancer depending on its histological type and extent, focusing mainly on locally advanced and borderline operable findings. The treatment of such heterogeneous group of tumors usually requires long-term and multidisciplinary approach. Description of four interesting case reports with pictorial documentation, description of the course of treatment and assessment of disability. Analysis and recommended evaluation of the percentage work ability reduction from the point of view of a medical assessor is provided for all individual case reports and compared against real assessments.
- MeSH
- Bronchi anatomy & histology blood supply MeSH
- Respiratory System * anatomy & histology embryology immunology blood supply physiopathology growth & development MeSH
- Respiration MeSH
- Respiratory Physiological Phenomena MeSH
- Hypoxia etiology MeSH
- Humans MeSH
- Mediastinum anatomy & histology MeSH
- Pleura anatomy & histology MeSH
- Lung anatomy & histology blood supply MeSH
- Pulmonary Ventilation physiology MeSH
- Ventilation-Perfusion Ratio MeSH
- Respiratory Transport physiology MeSH
- Trachea anatomy & histology MeSH
- Check Tag
- Humans MeSH
- Publication type
- Review MeSH
