Abstract: Computational fluid dynamics (CFD) has proven useful in the planning of upper airway surgery in humans, where it is used to anticipate the influence of the surgical procedures on post-operative airflow. This technology has only been reported twice in an equine model, with a limited scope of airflow mechanics situations examined. The reported study sought to widen this application to the variety of procedures used to treat equine recurrent laryngeal neuropathy (RLN). The first objective of this study was to generate a CFD model of an box model of ten different equine larynges replicating RLN and four therapeutic surgeries to compare the calculated impedance between these procedures for each larynx. The second objective was to determine the accuracy between a CFD model and measured airflow characteristics in equine larynges. The last objective was to explore the anatomic distribution of changes in pressure, velocity, and turbulent kinetic energy associated with the disease (RLN) and each surgical procedure performed. Unassigned: Ten equine cadaveric larynges underwent inhalation airflow testing in an instrumented box while undergoing a concurrent computed tomographic (CT) exam. The pressure upstream and downstream (outlet) were measured simultaneously. CT image segmentation was performed to generate stereolithography files, which underwent CFD analysis using the experimentally measured outlet pressure. The ranked procedural order and calculated laryngeal impedance were compared to the experimentally obtained values. Unassigned: The CFD model agreed with the measured results in predicting the procedure resulting in the lowest post-operative impedance in 9/10 larynges. Numerically, the CFD calculated laryngeal impedance was approximately 0.7 times that of the measured calculation. Low pressure and high velocity were observed around regions of tissue protrusion within the lumen of the larynx. RLN, the corniculectomy and partial arytenoidectomy surgical procedures exhibited low pressure troughs and high velocity peaks compared to the laryngoplasty and combined laryngoplasty/corniculectomy procedures. CFD modeling of the equine larynx reliably calculated the lowest impedance of the different surgical procedures. Future development of the CFD technique to this application may improve numerical accuracy and is recommended prior to consideration for use in patients.
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The study uses Computational Fluid Dynamics (CFD) to analyze and predict the impact of surgical procedures on airway flow in horses, generally used for treating a condition known as recurrent laryngeal neuropathy (RLN). The aim was to assess the accuracy of this model and determine its potential use for planning surgical procedures.
Study Objectives
The main purposes of this study were to create a CFD model based on CT scans of ten equine larynges, aiming to simulate RLN and four surgical procedures. It compared the calculated impedance (resistance) for each case.
Secondly, the study aimed to examine the correlation between the CFD model and the actual measured airflow characteristics in the horse’s larynx.
Finally, the study sought to investigate any changes in pressure, velocity, and turbulent kinetic energy linked with disease or each surgical procedure.
Methodology
Ten horse cadaver larynges were used for airflow testing in a controlled environment, alongside concurrent computed tomographic (CT) examinations.
Pressure readings were taken both upstream and downstream of the airflow, using the CT images to generate a model for the CFD analysis, factoring in the measured outlet pressure.
The study used the generated CFD models to compare and rank different surgical procedures based on the calculated impedance, and compared these results to the experimentally obtained values.
Results
The CFD model predictions closely matched with the measured results for 9 out of 10 larynges, indicating the lowest post-operative impedance for the projected surgical procedure.
The impulse calculated by the CFD model was around 0.7 times that of the experimentally measured calculation.
Observed areas of low pressure and high velocity were notable around regions of tissue protrusion within the larynx. This showed that RLN and two surgical procedures, known as corniculectomy and partial arytenoidectomy, resulted in low pressure troughs and high velocity peaks when compared to the laryngoplasty and combined laryngoplasty/corniculectomy procedures.
Conclusions
The CFD model was proven reliable in calculating the lowest impedance of the different surgical procedures.
It is recommended that further development of the CFD technique would improve numerical accuracy and contribute to more efficient pre-operational planning for equine patients with RLN.
Cite This Article
APA
Tucker ML, Wilson DG, Bergstrom DJ, Carmalt JL.
(2023).
Computational fluid dynamic analysis of upper airway procedures in equine larynges.
Front Vet Sci, 10, 1139398.
https://doi.org/10.3389/fvets.2023.1139398
Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, United States.
Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada.
Wilson, David G
Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada.
Bergstrom, Donald J
Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, SK, Canada.
Carmalt, James L
Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada.
Conflict of Interest Statement
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
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Citations
This article has been cited 1 times.
Tucker ML, Wilson DG, Bergstrom DJ, Carmalt JL. Comparison of treatments for equine laryngeal hemiplegia using computational fluid dynamic analysis in an equine head model. Front Vet Sci 2024;11:1478511.