Computational Fluid Dynamics in the assessment of nasal obstruction in children

Moreddu, E.; Meister, Lionel; Philip-Alliez, Camille; Triglia, Jean‐Michel; Médale, Marc; Nicollas, R.

doi:10.1016/j.anorl.2018.11.008

Cited by 18 publications

(11 citation statements)

References 25 publications

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“…5, it can be seen that in the case of patient 2, the local pressure distributions reach much higher values than in the case of patient 1. The series of studies from other authors presented similar findings in patients with nasal congestion [16,34,35].…”

Section: Discussionsupporting

confidence: 71%

“…Few articles report 3-D modeling of the upper respiratory tract with further analysis of airflow by means of CFD. The results of these studies performed on small groups of patients suggest the usefulness of this approach for the 35 14 49 397,273 795,414 2 a 30 10 40 157,998 316,416 3 b 13 3 16 987,349 1,795,234 4 b 15 2 17 997,316 1,726,033 5 5 2 7 813, assessment of airflow within the nasal cavity and paranasal sinuses [16,[19][20][21][24][25][26][27][28][29]. The discussed methodology enables simulation of airflow and prediction/simulation of airflow changes in patients after nasal and paranasal sinus surgeries, for both children and adults [17,30,31].…”

Section: Discussionmentioning

confidence: 95%

“…Seeking better understanding of the anatomical-functional relations, we focused on Computational Fluid Dynamics (CFD) studies which involve numerical methods to solve fluid flow issues [15][16][17][18][19][20]. Due to the discretization and numerical solution of partial differential equations describing the flow, it is possible to approximate the distribution of velocity, pressure, temperature, and other parameters in the flow.…”

Section: Introductionmentioning

confidence: 99%

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Three-dimensional modeling and automatic analysis of the human nasal cavity and paranasal sinuses using the computational fluid dynamics method

Tretiakow

Tesch

Meyer-Szary

et al. 2020

Eur Arch Otorhinolaryngol

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Purpose The goal of this study was to develop a complete workflow allowing for conducting computational fluid dynamics (CFD) simulation of airflow through the upper airways based on computed tomography (CT) and cone-beam computed tomography (CBCT) studies of individual adult patients. Methods This study is based on CT images of 16 patients. Image processing and model generation of the human nasal cavity and paranasal sinuses were performed using open-source and freeware software. 3-D Slicer was used primarily for segmentation and new surface model generation. Further processing was done using Autodesk® Meshmixer TM. The governing equations are discretized by means of the finite volume method. Subsequently, the corresponding algebraic equation systems were solved by OpenFOAM software. Results We described the protocol for the preparation of a 3-D model of the nasal cavity and paranasal sinuses and highlighted several problems that the future researcher may encounter. The CFD results were presented based on examples of 3-D models of the patient 1 (norm) and patient 2 (pathological changes). Conclusion The short training time for new user without a prior experience in image segmentation and 3-D mesh editing is an important advantage of this type of research. Both CBCT and CT are useful for model building. However, CBCT may have limitations. The Q criterion in CFD illustrates the considerable complication of the nasal flow and allows for direct evaluation and quantitative comparison of various flows and can be used for the assessment of nasal airflow.

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Section: Discussionsupporting

confidence: 71%

Section: Discussionmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

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Three-dimensional modeling and automatic analysis of the human nasal cavity and paranasal sinuses using the computational fluid dynamics method

Tretiakow

Tesch

Meyer-Szary

et al. 2020

Eur Arch Otorhinolaryngol

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“…However, CFD often provides lower resistances even when the two methods are compared at the same pressure difference. 27,54 For example, Radulesco and coauthors (2019) investigated unilateral nasal resistance at DP ¼ 75 Pa in 22 NAO patients and found a statistically significant difference between the two techniques (R CFD ¼ 0.8 AE 1.2 Pa.s/ml vs. R RMN ¼ 1.8 AE 2.2 Pa.s/ml in the most obstructed cavity; P ¼ 0.003). 12 Their results are consistent with our finding that CFD underpredicts nasal resistance when compared to RMN (Figures 5 and 6).…”

Section: Discussionmentioning

confidence: 99%

Rhinomanometry Versus Computational Fluid Dynamics: Correlated, but Different Techniques

Cherobin

Voegels

Pinna

et al. 2020

Am J Rhinol�Allergy

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Background Past studies reported a low correlation between rhinomanometry and computational fluid dynamics (CFD), but the source of the discrepancy was unclear. Low correlation or lack of correlation has also been reported between subjective and objective measures of nasal patency. Objective: This study investigates (1) the correlation and agreement between nasal resistance derived from CFD (RCFD) and rhinomanometry (RRMN), and (2) the correlation between objective and subjective measures of nasal patency. Methods Twenty-five patients with nasal obstruction underwent anterior rhinomanometry before and after mucosal decongestion with oxymetazoline. Subjective nasal patency was assessed with a 0-10 visual analog scale (VAS). CFD simulations were performed based on computed tomography scans obtained after mucosal decongestion. To validate the CFD methods, nasal resistance was measured in vitro (REXPERIMENT) by performing pressure-flow experiments in anatomically accurate plastic nasal replicas from 6 individuals. Results Mucosal decongestion was associated with a reduction in bilateral nasal resistance (0.34 ± 0.23 Pa.s/ml to 0.19 ± 0.24 Pa.s/ml, p = 0.003) and improved sensation of nasal airflow (bilateral VAS decreased from 5.2 ± 1.9 to 2.6 ± 1.9, p < 0.001). A statistically significant correlation was found between VAS in the most obstructed cavity and unilateral airflow before and after mucosal decongestion (r = −0.42, p = 0.003). Excellent correlation was found between RCFD and REXPERIMENT (r = 0.96, p < 0.001) with good agreement between the numerical and in vitro values (RCFD/REXPERIMENT = 0.93 ± 0.08). A weak correlation was found between RCFD and RRMN (r = 0.41, p = 0.003) with CFD underpredicting nasal resistance derived from rhinomanometry (RCFD/RRMN = 0.65 ± 0.63). A stronger correlation was found when unilateral airflow at a pressure drop of 75 Pa was used to compare CFD with rhinomanometry (r = 0.76, p < 0.001). Conclusion CFD and rhinomanometry are moderately correlated, but CFD underpredicts nasal resistance measured in vivo due in part to the assumption of rigid nasal walls. Our results confirm previous reports that subjective nasal patency correlates better with unilateral than with bilateral measurements and in the context of an intervention.

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“…Numerical fluid flow simulations, with the advantage of being noninvasive, are increasingly used by the medical and engineering communities. The study of respiratory physiology using Computational Fluid Dynamics (CFD) software is now widely recognized 19–22 . In addition, improving imaging techniques allow the realization of more accurate three‐dimensional anatomical model reconstructions 23 .…”

Section: Introductionmentioning

confidence: 99%

Heliox simulations for initial management of congenital laryngotracheal stenosis

Puppo

Meister

Médale

et al. 2022

Pediatric Pulmonology

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Objectives: Congenital laryngotracheal stenosis is rare, potentially severe, and difficult to manage. Heliox is a medical gas effective in obstructive airway pathologies, given its physical properties. This study aims to model the interest of Heliox in reducing the respiratory work in congenital laryngotracheal stenosis, using numerical fluid flow simulations, before considering its clinical use. Design: This is a retrospective study, performing Computational Fluid Dynamics numerical simulations of the resistances to airflow and three types of Heliox, on 3D reconstructions from CT scans of children presenting with laryngotracheal stenosis. Patients: Infants and children who were managed in the Pediatric ENT department of a tertiary-care center and underwent CT scanning for laryngotracheal stenosis between 2008 and 2018 were included.Results: Fourteen models of congenital laryngotracheal stenosis were performed in children aged from 16 days to 5 years, and one model of the normal trachea in a 5-year-old child. Tightest stenosis obtained the highest airway resistances, ranging from 40 to 10 kPa/L/s (up to 800 times higher than in the normal case).Heliox enabled a decrease in pressure drops and airway resistances in all stenosis cases, correlated to increasing Helium concentration.Conclusions: Heliox appears to reduce pressure drops and airway resistances in 3D models of laryngotracheal stenosis. It may represent a supportive treatment for laryngotracheal stenosis, while waiting for specialized care, thanks to the reduction of respiratory work.

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Computational Fluid Dynamics in the assessment of nasal obstruction in children

Cited by 18 publications

References 25 publications

Three-dimensional modeling and automatic analysis of the human nasal cavity and paranasal sinuses using the computational fluid dynamics method

Three-dimensional modeling and automatic analysis of the human nasal cavity and paranasal sinuses using the computational fluid dynamics method

Rhinomanometry Versus Computational Fluid Dynamics: Correlated, but Different Techniques

Heliox simulations for initial management of congenital laryngotracheal stenosis

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