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Hilliam Y, Armbruster CR, Rapsinski GJ, Marshall CW, Moore J, Koirala J, Krainz L, Gaston JR, Cooper VS, Lee SE, Bomberger JM. Cystic fibrosis pathogens persist in the upper respiratory tract following initiation of elexacaftor/tezacaftor/ivacaftor therapy. Microbiol Spectr 2024; 12:e0078724. [PMID: 38916354 PMCID: PMC11302335 DOI: 10.1128/spectrum.00787-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Accepted: 06/06/2024] [Indexed: 06/26/2024] Open
Abstract
Elexacaftor/tezacaftor/ivacaftor (ETI) therapy has revolutionized the treatment of cystic fibrosis (CF) for most affected individuals but the effects of treatment on sinus microbiota are still unknown. Changes to the airway microbiota in CF are associated with disease state and alterations to the bacterial community after ETI initiation may require changes to clinical management regimens. We collected sinus swab samples from the middle meatus in an observational study of 38 adults with CF and chronic rhinosinusitis (CRS) from 2017 to 2021 and captured the initiation of ETI therapy. We performed 16S and custom amplicon sequencing to characterize the sinus microbiota pre- and post-ETI. Real-time quantitative PCR (RT-qPCR) was performed to estimate total bacterial abundance. Sinus samples from people with CF (pwCF) clustered into three community types, dependent on the dominant bacterial organism: a Pseudomonas-dominant, Staphylococcus-dominant, and mixed dominance cluster. Shannon's diversity index was low and not significantly altered post-ETI. Total bacterial load was not significantly lowered post-ETI. Pseudomonas spp. abundance was significantly reduced post-ETI, but eradication was not observed. Staphylococcus spp. became the dominant organism in most individuals post-ETI and we showed the presence of methicillin-resistant Staphylococcus aureus (MRSA) in the sinus both pre- and post-ETI. We also demonstrated that the sinus microbiome is predictive of the presence of Pseudomonas spp., Staphylococcus spp., and Serratia spp. in the sputum. Pseudomonas spp. and Staphylococcus spp., including MRSA, persist in the sinuses of pwCF after ETI therapy, indicating that these pathogens will continue to be important in CF airway disease management in the era of highly effective modulator therapies (HEMT).IMPORTANCEHighly effective modulator therapies (HEMT), such as elexacaftor/tezacaftor/ivacaftor (ETI), for cystic fibrosis (CF) have revolutionized patient care and quality of life for most affected individuals. The effects of these therapies on the microbiota of the airways are still unclear, though work has already been published on changes to microbiota in the sputum. Our study presents evidence for reduced relative abundance of Pseudomonas spp. in the sinuses following ETI therapy. We also show that Staphylococcus spp. becomes the dominant organism in the sinus communities of most individuals in this cohort after ETI therapy. We identified methicillin-resistant Staphylococcus aureus (MRSA) in the sinus microbiota both pre- and post-therapy. These findings demonstrate that pathogen monitoring and treatment will remain a vital part of airway disease management for people with cystic fibrosis (pwCF) in the era of HEMT.
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Affiliation(s)
- Yasmin Hilliam
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Catherine R. Armbruster
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Glenn J. Rapsinski
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | | | - John Moore
- University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Junu Koirala
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Leah Krainz
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Jordan R. Gaston
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Vaughn S. Cooper
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Stella E. Lee
- University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Jennifer M. Bomberger
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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Wei H, Wan L, Zhang Y, Li Y, Xu W, Li Y, Han D. Value of Opening the Middle Meatus in Patients With Nasal Airway Obstruction. EAR, NOSE & THROAT JOURNAL 2023; 102:NP489-NP498. [PMID: 36916238 DOI: 10.1177/01455613231163737] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023] Open
Abstract
OBJECTIVES While surgeries to correct the anatomical malformations that cause nasal airway obstruction (NAO) are generally successful, the outcomes of such procedures are often unsatisfactory. The aim of the present study was to assess the value of opening the middle meatus in patients with NAO. METHODS Thirty-four patients with nasal obstruction due to nasal septal deviation were included in this study. After randomization, the middle meatus was either opened or not opened during septoplasty. The patients were evaluated through pre- and postoperative rhinomanometry and acoustic rhinometry. The Visual Analog Scale (VAS) scores of subjective symptoms along with responses to the 20-item Sinonasal Outcome Test (SNOT-20) were obtained before surgery and three months after surgery. RESULTS The VAS scores and SNOT-20 responses improved significantly in both groups after surgery. The effective treatment rate based on the nasal congestion score (NCS) was 64.7% in the single group (septoplasty alone) and 100% in the combined group (septoplasty in conjunction with opening the middle meatus), and the difference was statistically significant (P = .018). In both groups, surgery significantly improved nasal flow, resistance, minimal cross-sectional area, cross-sectional area 6 cm (CA6) from the anterior nostril and nasal volume. Nasal volume and CA6 after surgery were statistically different between the 2 groups (P = .004 and .019, respectively). CONCLUSIONS Opening the middle meatus may further improve the subjective perception of patency on the basis of septoplasty.
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Affiliation(s)
- Hongzheng Wei
- Department of Otolaryngology Head and Neck Surgery, Capital Medical University, Beijing Tongren Hospital, Beijing, People's Republic of China
- Department of Allergy, Capital Medical University, Beijing Tongren Hospital, Beijing, People's Republic of China
- Beijing Key Laboratory of Nasal Diseases, Beijing Institute of Otolaryngology, Beijing, People's Republic of China
| | - Lianqi Wan
- Department of Otolaryngology Head and Neck Surgery, Capital Medical University, Beijing Tongren Hospital, Beijing, People's Republic of China
- Department of Allergy, Capital Medical University, Beijing Tongren Hospital, Beijing, People's Republic of China
- Beijing Key Laboratory of Nasal Diseases, Beijing Institute of Otolaryngology, Beijing, People's Republic of China
| | - Yuan Zhang
- Department of Otolaryngology Head and Neck Surgery, Capital Medical University, Beijing Tongren Hospital, Beijing, People's Republic of China
- Department of Allergy, Capital Medical University, Beijing Tongren Hospital, Beijing, People's Republic of China
- Beijing Key Laboratory of Nasal Diseases, Beijing Institute of Otolaryngology, Beijing, People's Republic of China
| | - Yanru Li
- Department of Otolaryngology Head and Neck Surgery, Capital Medical University, Beijing Tongren Hospital, Beijing, People's Republic of China
| | - Wen Xu
- Department of Otolaryngology Head and Neck Surgery, Capital Medical University, Beijing Tongren Hospital, Beijing, People's Republic of China
| | - Yunchuan Li
- Department of Otolaryngology Head and Neck Surgery, Capital Medical University, Beijing Tongren Hospital, Beijing, People's Republic of China
- Beijing Key Laboratory of Nasal Diseases, Beijing Institute of Otolaryngology, Beijing, People's Republic of China
| | - Demin Han
- Department of Otolaryngology Head and Neck Surgery, Capital Medical University, Beijing Tongren Hospital, Beijing, People's Republic of China
- Beijing Key Laboratory of Nasal Diseases, Beijing Institute of Otolaryngology, Beijing, People's Republic of China
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3
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Li Q, Wang Z, Wang C, Wang HL. Characterizing the respiratory-induced mechanical stimulation at the maxillary sinus floor following sinus augmentation by computational fluid dynamics. Front Bioeng Biotechnol 2022; 10:885130. [PMID: 35957638 PMCID: PMC9360545 DOI: 10.3389/fbioe.2022.885130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 06/28/2022] [Indexed: 11/14/2022] Open
Abstract
Background: The relationship between maxillary sinus pneumatization and respiratory-induced fluid mechanics remains unclear. The purpose of this study was to simulate and measure the respiratory-induced mechanical stimulation at the sinus floor under different respiratory conditions and to investigate its potential effect on the elevated sinus following sinus-lifting procedures. Methods: The nasal airway together with the bilateral maxillary sinuses of the selected patient was segmented and digitally modeled from a computed tomographic image. The sinus floors of the models were elevated by simulated sinus augmentations using computer-aided design. The numerical simulations of sinus fluid motion under different respiratory conditions were performed using a computational fluid dynamics (CFD) algorithm. Sinus wall shear stress and static pressure on the pre-surgical and altered sinus floors were examined and quantitatively compared. Results: Streamlines with minimum airflow velocity were visualized in the sinus. The sinus floor pressure and the wall shear stress increased with the elevated inlet flow rate, but the magnitude of these mechanical stimulations remained at a negligible level. The surgical technique and elevated height had no significant influence on the wall pressure and the fluid mechanics. Conclusion: This study shows that respiratory-induced mechanical stimulation in the sinus floor is negligible before and after sinus augmentation.
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Affiliation(s)
- Qing Li
- Center of Digital Dentistry, Second Clinical Division, Peking University School and Hospital of Stomatology and National Center of Stomatology and National Clinical Research Center for Oral Diseases and National Engineering Research Center of Oral Biomaterials and Digital Medical Devices, Beijing, China
| | - Zhongyu Wang
- Center of Digital Dentistry, Second Clinical Division, Peking University School and Hospital of Stomatology and National Center of Stomatology and National Clinical Research Center for Oral Diseases and National Engineering Research Center of Oral Biomaterials and Digital Medical Devices, Beijing, China
| | - Chao Wang
- Key Laboratory of Biomechanics and Mechanobiology, Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, School of Engineering Medicine, Beihang University, Beijing, China
- *Correspondence: Chao Wang, ; Hom-Lay Wang,
| | - Hom-Lay Wang
- Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI, United States
- *Correspondence: Chao Wang, ; Hom-Lay Wang,
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4
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Becker S, Huppertz T, Möller W, Havel M, Schuster M, Becker AM, Sailer M, Schuschnig U, Johnson TR. Xenon-Enhanced Dynamic Dual-Energy CT Is Able to Quantify Sinus Ventilation Using Laminar and Pulsating Air-/Gas Flow Before and After Surgery: A Pilot Study in a Cadaver Model. FRONTIERS IN ALLERGY 2022; 3:829898. [PMID: 35386654 PMCID: PMC8974739 DOI: 10.3389/falgy.2022.829898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 01/14/2022] [Indexed: 11/13/2022] Open
Abstract
Background Chronic rhinosinusitis is a common disease with a significant impact on the quality of life. Topical drug delivery to the paranasal sinuses is not efficient to prevent sinus surgery or expensive biologic treatment in a lot of cases as the affected mucosa is not reached. More efficient approaches for topical drug delivery are, therefore, necessary. In the current study, dual-energy CT (DECT) imaging was used to examine sinus ventilation before and after sinus surgery using a pulsating xenon gas ventilator in a cadaver head. Methods Xenon gas was administered to the nasal cavity of a cadaver head with a laminar flow of 7 L/min and with pulsating xenon-flow (45 Hz frequency, 25 mbar amplitude). Nasal cavity and paranasal sinuses were imaged by DECT. This procedure was repeated after functional endoscopic sinus surgery (FESS). Based on the enhancement levels in the different sinuses, regional xenon concentrations were calculated. Results Xenon-related enhancement could not be detected in most of the sinuses during laminar gas flow. By superimposing laminar flow with pulsation, DECT imaging revealed a xenon wash-in and wash-out in the sinuses. After FESS, xenon enhancement was immediately seen in all sinuses and reached higher concentrations than before surgery. Conclusion Xenon-enhanced DECT can be used to visualize and quantify sinus ventilation. Pulsating air-/gas flow was superior to laminar flow for the administration of xenon to the paranasal sinuses. FESS leads to successful ventilation of all paranasal sinuses.
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Affiliation(s)
- Sven Becker
- Department of Otolaryngology, Head and Neck Surgery, Tübingen University Hospital, Tübingen, Germany
- *Correspondence: Sven Becker
| | - Tilman Huppertz
- Department of Otorhinolaryngology, Head and Neck Surgery, University Medical Centre, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Winfried Möller
- Institute of Lung Biology and Disease, Helmholtz Center München, Helmholtz Association of German Research Centres (HZ), Munich, Germany
| | - Miriam Havel
- Department of Otorhinolaryngology, Head and Neck Surgery, Ludwig-Maximilians-University, Munich, Germany
| | - Maria Schuster
- Department of Otorhinolaryngology, Head and Neck Surgery, Ludwig-Maximilians-University, Munich, Germany
| | - Anne Merle Becker
- Department of Otorhinolaryngology, Head and Neck Surgery, Ludwig-Maximilians-University, Munich, Germany
| | - Martin Sailer
- Department of Otolaryngology, Head and Neck Surgery, Tübingen University Hospital, Tübingen, Germany
| | | | - Thorsten R. Johnson
- Institute for Clinical Radiology, Ludwig-Maximilians-University, Munich, Germany
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Calmet H, Inthavong K, Owen H, Dosimont D, Lehmkuhl O, Houzeaux G, Vázquez M. Computational modelling of nasal respiratory flow. Comput Methods Biomech Biomed Engin 2020; 24:440-458. [PMID: 33175592 DOI: 10.1080/10255842.2020.1833865] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
CFD has emerged as a promising diagnostic tool for clinical trials, with tremendous potential. However, for real clinical applications to be useful, overall statistical findings from large population samples (e.g., multiple cases and models) are needed. Fully resolved solutions are not a priority, but rather rapid solutions with fast turn-around times are desired. This leads to the issue of what are the minimum modelling criteria for achieving adequate accuracy in respiratory flows for large-scale clinical applications, with a view to rapid turnaround times. This study simulated a highly-resolved solution using the large eddy simulation (LES) method as a reference case for comparison with lower resolution models that included larger time steps and no turbulence modelling. Differences in solutions were quantified by pressure loss, flow resistance, unsteadiness, turbulence intensity, and hysteresis effects from multiple cycles. The results demonstrated that sufficient accuracy could be achieved with lower resolution models if the mean flow was considered. Furthermore, to achieve an established transient result unaffected by the initial start-up quiescent effects, the results need to be taken from at least the second respiration cycle. It was also found that the exhalation phase exhibited strong turbulence. The results are expected to provide guidance for future modelling efforts for clinical and engineering applications requiring large numbers of cases using simplified modelling approaches.
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Affiliation(s)
- H Calmet
- Department of Computer Applications in Science and Engineering, Barcelona Supercomputing Center (BSC-CNS), Barcelona, Spain
| | - K Inthavong
- Mechanical & Automotive Engineering, School of Engineering, RMIT University, Melbourne, Australia
| | - H Owen
- Department of Computer Applications in Science and Engineering, Barcelona Supercomputing Center (BSC-CNS), Barcelona, Spain
| | - D Dosimont
- Department of Computer Applications in Science and Engineering, Barcelona Supercomputing Center (BSC-CNS), Barcelona, Spain
| | - O Lehmkuhl
- Department of Computer Applications in Science and Engineering, Barcelona Supercomputing Center (BSC-CNS), Barcelona, Spain
| | - G Houzeaux
- Department of Computer Applications in Science and Engineering, Barcelona Supercomputing Center (BSC-CNS), Barcelona, Spain
| | - M Vázquez
- Department of Computer Applications in Science and Engineering, Barcelona Supercomputing Center (BSC-CNS), Barcelona, Spain
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6
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Inthavong K, Das P, Singh N, Sznitman J. In silico approaches to respiratory nasal flows: A review. J Biomech 2019; 97:109434. [PMID: 31711609 DOI: 10.1016/j.jbiomech.2019.109434] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 09/15/2019] [Accepted: 10/17/2019] [Indexed: 12/20/2022]
Abstract
The engineering discipline of in silico fluid dynamics delivers quantitative information on airflow behaviour in the nasal regions with unprecedented detail, often beyond the reach of traditional experiments. The ability to provide visualisation and analysis of flow properties such as velocity and pressure fields, as well as wall shear stress, dynamically during the respiratory cycle may give significant insight to clinicians. Yet, there remains ongoing challenges to advance the state-of-the-art further, including for example the lack of comprehensive CFD modelling on varied cohorts of patients. The present article embodies a review of previous and current in silico approaches to simulating nasal airflows. The review discusses specific modelling techniques required to accommodate physiologically- and clinically-relevant findings. It also provides a critical summary of the reported results in the literature followed by an outlook on the challenges and topics anticipated to drive research into the future.
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Affiliation(s)
| | - Prashant Das
- Department of Mechanical Engineering, University of Alberta, Edmonton, Canada
| | - Narinder Singh
- Dept of Otolaryngology, Head & Neck Surgery, Westmead Hospital Clinical School, Faculty of Medicine, University of Sydney, Australia
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa, Israel
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7
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Zhang Y, Shang Y, Inthavong K, Tong Z, Sun B, Zhu K, Yu A, Zheng G. Computational investigation of dust mite allergens in a realistic human nasal cavity. Inhal Toxicol 2019; 31:224-235. [PMID: 31431101 DOI: 10.1080/08958378.2019.1647315] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Aim: Inhaled allergens from house dust mite (HDM) are a major source of allergic disease such as allergic rhinitis and asthma. It has been a challenge to properly evaluate health risks caused by HDM related allergens including mite bodies, eggs and fecal pellets. This paper presents a numerical study on particle deposition of dust mite allergens in a human nasal cavity. Materials and methods: A realistic nasal cavity model was reconstructed from CT scans and a Computational Fluid Dynamics analysis of steady airflow was simulated. The discrete phase model was used to trace particle trajectories of three dust mite related particles. Results: The flow and particle model were validated by comparing with nasal resistance measurement and previous literature respectively. Aerodynamic characteristics and deposition of dust mite allergens in the nasal cavity were analyzed under different breathing conditions including rest and exercising conditions. Conclusions: The numerical results revealed the roles of different nasal cavity regions in filtering various types of dust mite allergens with consideration of breathing conditions.
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Affiliation(s)
- Ya Zhang
- Department of Otolaryngology Head and Neck Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University , Xi'an , China
| | - Yidan Shang
- College of Air Transportation, Shanghai University of Engineering Science , Shanghai , China.,School of Engineering, RMIT University , Bundoora , Australia
| | - Kiao Inthavong
- School of Engineering, RMIT University , Bundoora , Australia
| | - Zhenbo Tong
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University , Nanjing , China
| | - Bin Sun
- Department of Otolaryngology Head and Neck Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University , Xi'an , China
| | - Kang Zhu
- Department of Otolaryngology Head and Neck Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University , Xi'an , China
| | - Aibing Yu
- Laboratory for Simulation and Modelling of Particulate Systems, Department of Chemical Engineering, Monash University , Clayton , Australia
| | - Guoxi Zheng
- Department of Otolaryngology Head and Neck Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University , Xi'an , China
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8
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The influence of orbital decompression on objective nasal function in patients with graves' orbitopathy. Eur Arch Otorhinolaryngol 2018; 275:2507-2513. [PMID: 30167837 DOI: 10.1007/s00405-018-5105-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 08/21/2018] [Indexed: 01/22/2023]
Abstract
PURPOSE To determine the influence of anatomical changes after orbital decompression to nasal function. METHODS We examined postoperative nasal function after orbital decompression in patients with GO in a prospective study. 25 patients were enrolled between 2014 and 2016. Sense of smell (Sniffin' Test) and nasal airflow (anterior rhinomanometry) were tested pre- and 6 weeks postoperatively. In addition, postoperative incidence of sinus infections, persistent pressure pain, and infraorbital hypoesthesia were assessed by means of a questionnaire. RESULTS The olfactory performance showed a significant increase (p < 0.05) after surgery, while the nasal airflow significantly decreased (p < 0.05). Acute sinus infection occurred in three, infraorbital sensibility disorders in eight cases within the first 6 weeks after surgery. No persistent pain was recorded. CONCLUSION We demonstrate that decompression of the medial orbital wall leads to a decrease in nasal airflow, whereof patients should be informed before the procedure. This is most likely due to a medialization of the medial turbinate and the prolapse of orbital content into the nasal cavity. The increase of the olfactory performance is, in our opinion, more likely due to variation within the standard deviation than to anatomical changes.
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9
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Basu S, Frank-Ito DO, Kimbell JS. On computational fluid dynamics models for sinonasal drug transport: Relevance of nozzle subtraction and nasal vestibular dilation. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2018; 34:e2946. [PMID: 29172251 PMCID: PMC5893392 DOI: 10.1002/cnm.2946] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 10/05/2017] [Accepted: 11/12/2017] [Indexed: 05/23/2023]
Abstract
Generating anatomically realistic 3-dimensional (3D) models of the human sinonasal cavity for numerical investigations of sprayed drug transport presents a host of methodological ambiguities. For example, subject-specific radiographic images used for 3D reconstructions typically exclude spray bottles. Subtracting a bottle contour from the 3D airspace and dilating the anterior nasal vestibule for nozzle placement augment the complexity of model building. So we explored the question: how essential are these steps to adequately simulate nasal airflow and identify the optimal delivery conditions for intranasal sprays? In particular, we focused on particle deposition patterns in the maxillary sinus, a critical target site for chronic rhinosinusitis. The models were reconstructed from postsurgery computed tomography scans for a 39-year-old Caucasian male, with chronic rhinosinusitis history. Inspiratory airflow patterns during resting breathing are reliably tracked through computational fluid dynamics-based steady-state laminar-viscous modeling, and such regimes portray relative lack of sensitivity to inlet perturbations. Consequently, we hypothesized that the posterior airflow transport and the particle deposition trends should not be radically affected by the nozzle subtraction and vestibular dilation. The study involved 1 base model and 2 derived models; the latter 2 with nozzle contours (2 different orientations) subtracted from the dilated anterior segment of the left vestibule. We analyzed spray transport in the left maxillary sinus for multiple release conditions. Similar release points, localized on an approximately 2 mm × 4.5 mm contour, facilitated improved maxillary deposition in all 3 test cases. This suggests functional redundancy of nozzle insertion in a 3D numerical model for identifying the optimal spray release locations.
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Affiliation(s)
- Saikat Basu
- Computing and Clinical Research Lab, Department of Otolaryngology/Head and Neck Surgery, The University of North Carolina – School of Medicine, Chapel Hill, NC 27599, USA
| | - Dennis O. Frank-Ito
- Div. of Head & Neck Surgery & Communication Sciences, Duke University Medical Center, Durham, NC 27710, USA
- Computational Biology and Bioinformatics Program, Duke University, Durham, NC 27708, USA
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC 27708, USA
| | - Julia S. Kimbell
- Computing and Clinical Research Lab, Department of Otolaryngology/Head and Neck Surgery, The University of North Carolina – School of Medicine, Chapel Hill, NC 27599, USA
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10
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de Gabory L, Reville N, Baux Y, Boisson N, Bordenave L. Numerical simulation of two consecutive nasal respiratory cycles: toward a better understanding of nasal physiology. Int Forum Allergy Rhinol 2018; 8:676-685. [PMID: 29337433 DOI: 10.1002/alr.22086] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 11/27/2017] [Accepted: 12/14/2017] [Indexed: 10/18/2022]
Abstract
BACKGROUND Computational fluid dynamic (CFD) simulations have greatly improved the understanding of nasal physiology. We postulate that simulating the entire and repeated respiratory nasal cycles, within the whole sinonasal cavities, is mandatory to gather more accurate observations and better understand airflow patterns. METHODS A 3-dimensional (3D) sinonasal model was constructed from a healthy adult computed tomography (CT) scan which discretized in 6.6 million cells (mean volume, 0.008 mm3 ). CFD simulations were performed with ANSYS©FluentTMv16.0.0 software with transient and turbulent airflow (k-ω model). Two respiratory cycles (8 seconds) were simulated to assess pressure, velocity, wall shear stress, and particle residence time. RESULTS The pressure gradients within the sinus cavities varied according to their place of connection to the main passage. Alternations in pressure gradients induced a slight pumping phenomenon close to the ostia but no movement of air was observed within the sinus cavities. Strong movements were observed within the inferior meatus during expiration contrary to the inspiration, as in the olfactory cleft at the same time. Particle residence time was longer during expiration than inspiration due to nasal valve resistance, as if the expiratory phase was preparing the next inspiratory phase. Throughout expiration, some particles remained in contact with the lower turbinates. The posterior part of the olfactory cleft was gradually filled with particles that did not leave the nose at the next respiratory cycle. This pattern increased as the respiratory cycle was repeated. CONCLUSION CFD is more efficient and reliable when the entire respiratory cycle is simulated and repeated to avoid losing information.
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Affiliation(s)
- Ludovic de Gabory
- Ear, Nose, and Throat (ENT) Department, University Hospital of Bordeaux, Hôpital Pellegrin, Bordeaux, France.,Centre d'Investigation Clinique et d'Innovation Technologique de Bordeaux (CIC-IT 14-01), University Hospital of Bordeaux, France.,University of Bordeaux, Bordeaux, France
| | - Nicolas Reville
- Ear, Nose, and Throat (ENT) Department, University Hospital of Bordeaux, Hôpital Pellegrin, Bordeaux, France.,University of Bordeaux, Bordeaux, France
| | - Yannick Baux
- OPTIFLUIDES, Computational Fluid Dynamics Unit, Villeurbanne, France
| | - Nicolas Boisson
- OPTIFLUIDES, Computational Fluid Dynamics Unit, Villeurbanne, France
| | - Laurence Bordenave
- Centre d'Investigation Clinique et d'Innovation Technologique de Bordeaux (CIC-IT 14-01), University Hospital of Bordeaux, France.,University of Bordeaux, Bordeaux, France.,Institut National de la Santé et de la Recherche Médicale (INSERM), Bioingénierie tissulaire U1026, Bordeaux, France
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11
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Perkins EL, Basu S, Garcia GJM, Buckmire RA, Shah RN, Kimbell JS. Ideal Particle Sizes for Inhaled Steroids Targeting Vocal Granulomas: Preliminary Study Using Computational Fluid Dynamics. Otolaryngol Head Neck Surg 2017; 158:511-519. [PMID: 29160160 DOI: 10.1177/0194599817742126] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Objectives Vocal fold granulomas are benign lesions of the larynx commonly caused by gastroesophageal reflux, intubation, and phonotrauma. Current medical therapy includes inhaled corticosteroids to target inflammation that leads to granuloma formation. Particle sizes of commonly prescribed inhalers range over 1 to 4 µm. The study objective was to use computational fluid dynamics to investigate deposition patterns over a range of particle sizes of inhaled corticosteroids targeting the larynx and vocal fold granulomas. Study Design Retrospective, case-specific computational study. Setting Tertiary academic center. Subjects/Methods A 3-dimensional anatomically realistic computational model of a normal adult airway from mouth to trachea was constructed from 3 computed tomography scans. Virtual granulomas of varying sizes and positions along the vocal fold were incorporated into the base model. Assuming steady-state, inspiratory, turbulent airflow at 30 L/min, computational fluid dynamics was used to simulate respiratory transport and deposition of inhaled corticosteroid particles ranging over 1 to 20 µm. Results Laryngeal deposition in the base model peaked for particle sizes 8 to 10 µm (2.8%-3.5%). Ideal sizes ranged over 6 to 10, 7 to 13, and 7 to 14 µm for small, medium, and large granuloma sizes, respectively. Glottic deposition was maximal at 10.8% for 9-µm-sized particles for the large posterior granuloma, 3 times the normal model (3.5%). Conclusion As the virtual granuloma size increased and the location became more posterior, glottic deposition and ideal particle size generally increased. This preliminary study suggests that inhalers with larger particle sizes, such as fluticasone propionate dry-powder inhaler, may improve laryngeal drug deposition. Most commercially available inhalers have smaller particles than suggested here.
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Affiliation(s)
- Elizabeth L Perkins
- 1 Department of Otolaryngology/Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Saikat Basu
- 1 Department of Otolaryngology/Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Guilherme J M Garcia
- 2 Department of Otolaryngology and Communication Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.,3 Biotechnology and Bioengineering Center, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Robert A Buckmire
- 1 Department of Otolaryngology/Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Rupali N Shah
- 1 Department of Otolaryngology/Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Julia S Kimbell
- 1 Department of Otolaryngology/Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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Choi KJ, Jang DW, Ellison MD, Frank-Ito DO. Characterizing airflow profile in the postoperative maxillary sinus by using computational fluid dynamics modeling: A pilot study. Am J Rhinol Allergy 2016; 30:29-36. [PMID: 26867527 DOI: 10.2500/ajra.2016.30.4266] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Maxillary antrostomy is commonly performed during endoscopic sinus surgery. Little is known about the association surrounding recalcitrant maxillary sinusitis, antrostomy size, and intranasal airflow changes. Furthermore, the interaction between sinus mucosa and airflow is poorly understood. This study used computational fluid dynamics (CFD) modeling to investigate postoperative airflow characteristics between diseased and nondiseased maxillary sinuses in subjects with recurrent disease. METHODS A retrospective review of patients from a tertiary-level academic rhinology practice was performed. Seven subjects with endoscopic evidence of postoperative maxillary sinus disease that presented as chronic unilateral crusting at least 1 year after bilateral maxillary antrostomies were selected. A three-dimensional model of each subject's sinonasal cavity was created from postoperative computed tomographies and used for CFD analysis. RESULTS Although the variables investigated between diseased and nondiseased sides were not statistically significant, the diseased side in six subjects had a smaller antrostomy, and five of these subjects had both reduced nasal unilateral airflow and increased unilateral nasal resistance on the diseased side. The ratio of posterior wall shear stress (WSS) of the maxillary sinus to the total WSS was higher on the diseased side in six subjects. Results also showed strong correlations between antrostomy and CFD variables on the diseased side than on the nondiseased side. CONCLUSION This pilot study showed that the majority of the simulated sinonasal models exhibited common characteristics on the side with persistent disease, such as smaller antrostomy, reduced nasal airflow, increased nasal resistance, and increased posterior WSS. Although statistical significance was not established, this study provided preliminary insight into variables to consider in a larger cohort study.
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Affiliation(s)
- Kevin J Choi
- Department of Surgery, Division of Head and Neck Surgery & Communication Sciences, Duke University Medical Center, Durham, North Carolina, USA
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13
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Jain R, Kumar H, Tawhai M, Douglas R. The impact of endoscopic sinus surgery on paranasal physiology in simulated sinus cavities. Int Forum Allergy Rhinol 2016; 7:248-255. [PMID: 27869357 DOI: 10.1002/alr.21879] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2016] [Revised: 10/05/2016] [Accepted: 10/18/2016] [Indexed: 01/25/2023]
Abstract
BACKGROUND Surgery improves symptoms for the majority of chronic rhinosinusitis (CRS) patients; however, physiological changes in the sinus cavities remain poorly characterized. Direct measurement of changes in airflow, pressure, temperature, humidity, and intranasal spray distribution following surgery is technically challenging. Accordingly, we have used computational fluid dynamic modeling to quantify how these parameters change postoperatively. METHODS Computed tomography images from a normal control, a patient with CRS preoperatively and postoperatively, and a patient following an endoscopic Lothrop procedure (ELP) were used to create 4 three-dimensional models of the sinus cavities. Changes in physiologic parameters and topical drug distribution were modeled (inhaled air at 16°C and 10% humidity) at the maxillary ostium, frontal recess, and sphenoid ostium. RESULTS Large differences were seen between models. Following surgery, the maxillary ostia were found on average to be cooler (by 2.4°C), with an increased airflow (0.26 m/second; from 0 m/second), and a 9% reduction in absolute humidity. Sphenoid ostial parameters followed a similar trend. Significant changes in frontal recess physiology were seen following ELP in which the recess was 4.2°C cooler, had increased airflow (0.76 m/second) and a 17% reduction in absolute humidity. Topical drug distribution increased with surgery, particularly after ELP. CONCLUSION Surgery changes the geometry and physiology of the paranasal sinuses. These changes are likely to have an impact on wound healing, mucociliary function, and microbial ecology in postoperative cavities. Application of this model to further understand the effects of surgery may help to optimize surgical techniques and improve topical drug delivery.
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Affiliation(s)
- Ravi Jain
- Department of Surgery, The University of Auckland, Auckland, New Zealand
| | - Haribalan Kumar
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Merryn Tawhai
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Richard Douglas
- Department of Surgery, The University of Auckland, Auckland, New Zealand
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14
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Kumar H, Jain R, Douglas RG, Tawhai MH. Airflow in the Human Nasal Passage and Sinuses of Chronic Rhinosinusitis Subjects. PLoS One 2016; 11:e0156379. [PMID: 27249219 PMCID: PMC4889048 DOI: 10.1371/journal.pone.0156379] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 05/13/2016] [Indexed: 11/18/2022] Open
Abstract
Endoscopic surgery is performed on patients with chronic inflammatory disease of the paranasal sinuses to improve sinus ventilation. Little is known about how sinus surgery affects sinonasal airflow. In this study nasal passage geometry was reconstructed from computed tomographic imaging from healthy normal, pre-operative, and post-operative subjects. Transient air flow through the nasal passage during calm breathing was simulated. Subject-specific differences in ventilation of the nasal passage were observed. Velocity magnitude at ostium was different between left and right airway. In FESS, airflow in post-surgical subjects, airflow at the maxillary sinus ostium was upto ten times higher during inspiration. In a Lothrop procedure, airflow at the frontal sinus ostium can be upto four times higher during inspiration. In both post-operative subjects, airflow at ostium was not quasi-steady. The subject-specific effect (of surgery) on sinonasal interaction evaluated through airflow simulations may have important consequences for pre- and post-surgical assessment and surgical planning, and design for improvement of the delivery efficiency of nasal therapeutics.
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Affiliation(s)
- Haribalan Kumar
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
- * E-mail:
| | - Ravi Jain
- Department of surgery, The University of Auckland, Auckland, New Zealand
| | - Richard G. Douglas
- Department of surgery, The University of Auckland, Auckland, New Zealand
| | - Merryn H. Tawhai
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
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Faramarzi M, Baradaranfar MH, Abouali O, Atighechi S, Ahmadi G, Farhadi P, Keshavarzian E, Behniafard N, Baradaranfar A. Numerical investigation of the flow field in realistic nasal septal perforation geometry. ALLERGY & RHINOLOGY 2014; 5:70-7. [PMID: 24988523 PMCID: PMC4124581 DOI: 10.2500/ar.2014.5.0090] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The computational fluid dynamics (CFD) are used to evaluate the physiological function of the nose. We evaluated the aerodynamics of the nasal cavity in a patient with septal perforation (SP), pre- and postvirtual repair. Three-dimensional nasal models were reconstructed, and then a wide range of the pressure drops and flow rates were analyzed. The airflow velocity is higher in the central region and is lower around the boundary of the SP. The air velocity in the SP increases as the pressure drop increases. Furthermore, at the anterior part of the SP, the shear stress is higher in the upper part. In addition, the repair of SP does not affect the total nasal airflow rate and the velocity contour patterns. The potential usage of the CFD technique as a predictive technique to explore the details and a preoperative assessment tool to help in clinical decision making in nasal surgery is emphasized.
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Affiliation(s)
- Mohammad Faramarzi
- Department of Otolaryngology, Head and Neck Surgery, Shiraz University of Medical Sciences, Shiraz, Iran
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Zhu JH, Lim KM, Thong KTM, Wang DY, Lee HP. Assessment of airflow ventilation in human nasal cavity and maxillary sinus before and after targeted sinonasal surgery: a numerical case study. Respir Physiol Neurobiol 2014; 194:29-36. [PMID: 24418355 DOI: 10.1016/j.resp.2014.01.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2012] [Revised: 01/02/2014] [Accepted: 01/03/2014] [Indexed: 11/16/2022]
Abstract
In this study, we evaluated the effects of targeted sinonasal surgery on nasal and maxillary sinus airflow patterns. A patient, who underwent right balloon sinuplasty and left uncinectomy for recurrent maxillary sinus barometric pressure, and concomitant septoplasty and bilateral inferior turbinate reduction for deviated nasal septum and inferior turbinate hypertrophy, was selected. Two 3D models representing both pre- and post-operative sinonasal morphology were constructed. The models were then used to evaluate nasal and maxillary sinus airflow patterns during respiration at ventilation rates of 7.5 L/min, 15 L/min and 30 L/min using computational fluid dynamics. The results showed that septoplasty and inferior turbinate reduction increased the nasal volume by 13.6%. The airflow patterns in the nasal cavity showed reasonably decreased resistance and slightly more even flow partitioning after the operation. Maxillary sinus ventilation significantly increased during inspiration in the left sinus after uncinectomy, and during expiration in right sinus after balloon sinuplasty. This study demonstrates computational fluid dynamics simulation is a tool in the investigation of outcomes after targeted, minimally invasive sinonasal surgery.
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Affiliation(s)
- Jian Hua Zhu
- Department of Mechanical Engineering, National University of Singapore, Singapore, Singapore
| | - Kian Meng Lim
- Department of Mechanical Engineering, National University of Singapore, Singapore, Singapore
| | - Kim Thye Mark Thong
- Department of Otolaryngology, National University Health System, Singapore, Singapore.
| | - De Yun Wang
- Department of Otolaryngology, National University Health System, Singapore, Singapore
| | - Heow Pueh Lee
- Department of Mechanical Engineering, National University of Singapore, Singapore, Singapore; National University of Singapore (Suzhou) Research Institute, 377 Lin Quan Street, Suzhou Industrial Park, Jiang Su, People's Republic of China
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Frank DO, Zanation AM, Dhandha VH, McKinney KA, Fleischman GM, Ebert CS, Senior BA, Kimbell JS. Quantification of airflow into the maxillary sinuses before and after functional endoscopic sinus surgery. Int Forum Allergy Rhinol 2013; 3:834-40. [PMID: 24009143 DOI: 10.1002/alr.21203] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Revised: 05/24/2013] [Accepted: 06/18/2013] [Indexed: 11/10/2022]
Abstract
BACKGROUND The effects of increases in maxillary sinus (MS) airflow following functional endoscopic sinus surgery (FESS) are unknown. The goal of this study was to quantify the effects of FESS on airflow into the MS in a cohort of patients with chronic rhinosinusitis, and compare MS flow rate with patient-reported outcome measures. METHODS A pilot study was conducted in which preoperative and postoperative computed tomography scans of 4 patients undergoing bilateral or unilateral FESS were used to create 3-dimensional (3D) reconstructions of the nasal airway and paranasal sinuses using Mimics™ (Materialise, Inc.). The size of the maxillary antrostomies post-FESS ranged from 107 to 160 mm(2). Computational meshes were generated from the 3D reconstructions, and steady-state, laminar, inspiratory airflow was simulated in each mesh using the computational fluid dynamics (CFD) software Fluent™ (ANSYS, Inc.) under physiologic, pressure-driven conditions. Airflow into the MS was estimated from the simulations and was compared preoperatively and postoperatively. In addition, patients completed preoperative and postoperative Rhinosinusitis Outcome Measure-31 (RSOM-31) questionnaires and scores were compared with MS airflow rates. RESULTS CFD simulations predicted that average airflow rate into post-FESS MS increased by 18.5 mL/second, and that average flow velocity into the MS more than quadrupled. Simulation results also showed that MS flow rate trended with total RSOM-31 and all domain scores. CONCLUSION CFD simulations showed that the healed maxillary antrostomy after FESS can greatly enhance airflow into the MS. Our pilot study suggests that to some extent, increasing airflow into the MS may potentially improve chronic rhinosinusitis patients' quality of life pre-FESS and post-FESS.
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Affiliation(s)
- Dennis O Frank
- Department of Otolaryngology-Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, NC
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Kim YH, Lee SH, Park CW, Cho JH. Nasalance change after sinonasal surgery: analysis of voice after septoturbinoplasty and endoscopic sinus surgery. Am J Rhinol Allergy 2013; 27:67-70. [PMID: 23406604 DOI: 10.2500/ajra.2013.27.3832] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Changes in nasalance caused by resonance change after endonasal surgeries have been reported in prior studies. In clinical practice, although patients often complain of a nasal voice just after surgery, their voices recover over time. The objective of this study was to evaluate the long-term nasalance changes before and after endonasal surgery. METHODS Patients who underwent sinonasal surgery at Yeouido St. Mary's Hospital between March 2009 and July 2011 were included in this study. We classified the subjects into three groups according to the surgeries they underwent: group 1, the septoturbinoplasty group; group 2, the endoscopic sinus surgery group; and group 3, the septoturbinoplasty and endoscopic sinus surgery group. We checked acoustic profiles, Grade, Roughness, Breathiness, Asthenia, Strain (GRBAS) scores, and nasalance using a nasometer before and after the sinonasal surgery. RESULTS When considering multidimensional voice program results, no observed parameters showed statistically meaningful changes before or after the operation in all three groups. GRBAS scales in all patients changed less than two scales postoperatively. Nasalance increased at 1 month after the operation in all groups. However, it returned to original levels with time: 3 months in group 2 and 6 months in groups 1 and 3. CONCLUSION Sinonasal surgery can change the acoustic characteristics of the vocal tract and produce a significant increase in nasality in the early phase. However, after proper healing of the nasal cavity, nasality was observed to become similar to the preoperative level. Therefore, patients, especially voice professionals, do not need to be wary of voice changes after sinonasal surgery.
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Affiliation(s)
- Young Ha Kim
- Department of Otolaryngology-Head and Neck Surgery, Yeouido St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea
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Impacts of fluid dynamics simulation in study of nasal airflow physiology and pathophysiology in realistic human three-dimensional nose models. Clin Exp Otorhinolaryngol 2012. [PMID: 23205221 PMCID: PMC3506767 DOI: 10.3342/ceo.2012.5.4.181] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
During the past decades, numerous computational fluid dynamics (CFD) studies, constructed from CT or MRI images, have simulated human nasal models. As compared to rhinomanometry and acoustic rhinometry, which provide quantitative information only of nasal airflow, resistance, and cross sectional areas, CFD enables additional measurements of airflow passing through the nasal cavity that help visualize the physiologic impact of alterations in intranasal structures. Therefore, it becomes possible to quantitatively measure, and visually appreciate, the airflow pattern (laminar or turbulent), velocity, pressure, wall shear stress, particle deposition, and temperature changes at different flow rates, in different parts of the nasal cavity. The effects of both existing anatomical factors, as well as post-operative changes, can be assessed. With recent improvements in CFD technology and computing power, there is a promising future for CFD to become a useful tool in planning, predicting, and evaluating outcomes of nasal surgery. This review discusses the possibilities and potential impacts, as well as technical limitations, of using CFD simulation to better understand nasal airflow physiology.
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