• 1.

    Speirs VC. Partial arytenoidectomy in horses. Vet Surg. 1986;15:316320.

  • 2.

    Barnes AJ, Slone DE, Lynch TM. Performance after partial arytenoidectomy without mucosal closure in 27 Thoroughbred racehorses. Vet Surg. 2004;33(4):398403. doi:10.1111/j.1532-950X.2004.04058.x

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 3.

    Compostella F, Tremaine WH, Franklin SH. Retrospective study investigating causes of abnormal respiratory noise in horses following prosthetic laryngoplasty. Equine Vet J Suppl. 2012;44(43):2730. doi:10.1111/j.2042-3306.2012.00612.x

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 4.

    Witte TH, Mohammed HO, Radcliffe CH, Hackett RP, Ducharme NG. Racing performance after combined prosthetic laryngoplasty and ipsilateral ventriculocordectomy or partial arytenoidectomy: 135 Thoroughbred racehorses competing less than 2400 m (1997–2007). Equine Vet J. 2009;41(1):7075. doi:10.2746/042516408x343163

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 5.

    Jansson N, Ducharme NG, Hackett RP, Mohammed HO. An in vitro comparison of cordopexy, cordopexy and laryngoplasty, and laryngoplasty for treatment of equine laryngeal hemiplegia. Vet Surg. 2000;29(4):326334. doi:10.1053/jvet.2000.5599

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 6.

    Cheetham J, Witte TH, Soderholm LV, Hermanson JW, Ducharme NG. In vitro model for testing novel implants for equine laryngoplasty. Vet Surg. 2008;37(6):588593. doi:10.1111/j.1532-950X.2008.00424.x

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 7.

    Tucker ML, Sumner D, Reinink S, Wilson DG, Carmalt JL. Ex vivo evaluation of laryngoplasty, arytenoid corniculectomy, and partial arytenoidectomy for equine recurrent laryngeal neuropathy. Am J Vet Res. 2019;80(12):11361143. doi:10.2460/ajvr.80.12.1136

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 8.

    Williams JW, Pascoe JR, Meagher DM, Hornof WJ. Effects of left recurrent laryngeal neurectomy, prosthetic laryngoplasty, and subtotal arytenoidectomy on upper airway pressure during maximal exertion. Vet Surg. 1990;19(2):136141. doi:10.1111/j.1532-950x.1990.tb01155.x

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 9.

    Derksen FJ, Stick JA, Scott EA, Robinson NE, Slocombe RF. Effect of laryngeal hemiplegia and laryngoplasty on airway flow mechanics in exercising horses. Am J Vet Res. 1986;47(1):1620.

    • Search Google Scholar
    • Export Citation
  • 10.

    Williams JW, Meagher DM, Pascoe JR, Hornof WJ. Upper airway function during maximal exercise in horses with obstructive airway lesions: effect of surgical treatment. Vet Surg. 1990;19(2):142147. doi:10.1111/j.1532-950x.1990.tb01156.x

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 11.

    Hawkins JF, Couetil L, Miller MA. Maintenance of arytenoid abduction following carbon dioxide laser debridement of the articular cartilage and joint capsule of the cricoarytenoid joint combined with the prosthetic laryngoplasty in horses: an in vivo and in vitro study. Vet J. 2014;199(2):275280. doi:10.1016/j.tvjl.2013.11.027

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 12.

    Ahern BJ, Lim YW, van Eps A, Franklin S. In vitro evaluation of the effect of a prototype dynamic laryngoplasty system on arytenoid abduction. Vet Surg. 2018;47(6):837842. doi:10.1111/vsu.12933

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 13.

    Perkins JD, Meighan H, Windley Z, Troester S, Piercy R, Schumacher J. In vitro effect of ventriculocordectomy before laryngoplasty on abduction of the equine arytenoid cartilage. Vet Surg. 2011;40(3):305310. doi:10.1111/j.1532-950X.2011.00796.x

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 14.

    Adam NJ, De Ceseare G, Schleiss AJ. Influence of geometrical parameters of chamfered or rounded orifices on head losses. J Hydraul Res. 2019;57(2):263271. doi:10.1080/00221686.2018.1454518

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 15.

    Fossa M, Guglielmini G. Pressure drop and void fraction profiles during horizontal flow through thick and thin orifices. Exp Therm Fluid Sci. 2002;26:513523.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 16.

    Scherer RC, Shinwari D, De Witt KJ, Zhang C, Kucinschi BR, Afjeh AA. Intraglottal pressure profiles for a symmetric and oblique glottis with a divergence angle of 10 degrees. J Acoust Soc Am. 2001;109(4):16161630. doi:10.1121/1.1333420

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 17.

    Johnstone A, Uddin M, Pollard A, et al. The flow inside an idealized form of the human extra-thoracic airway. Exp Fluids. 2004;37:673689. doi:10.1007/s00348-004-0857-4

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 18.

    International Organization for Standardization. Measurement of fluid flow by means of pressure differential devices inserted in circular cross-section conduits running full—part 1: general principles and requirements (ISO 5167). Accessed Mar 17, 2020. https://www.iso.org/standard/28064.html

    • Search Google Scholar
    • Export Citation
  • 19.

    Nielan GJ, Rehder RS, Ducharme NG, Hackett RP. Measurement of tracheal static pressure in exercising horses. Vet Surg. 1992;21(6):423428. doi:10.1111/j.1532-950x.1992.tb00075.x

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 20.

    Rakesh V, Ducharme NG, Datta AK, Cheetham J, Pease AP. Development of equine upper airway fluid mechanics model for Thoroughbred racehorses. Equine Vet J. 2008;40(3):272279. doi:10.2746/042516408X281216

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 21.

    White NA, Blackwell RB. Partial arytenoidectomy in the horse. Vet Surg. 1980;9:512.

  • 22.

    Perkins JD, Raffetto J, Thompson C, Weller R, Piercy RJ, Pfau T. Three-dimensional biomechanics of simulated laryngeal abduction in horses. Am J Vet Res. 2010;71(9):10031010. doi:10.2460/ajvr.71.9.1003

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 23.

    Lynch NP, Jones SA, Bazley-White LG, et al. Ex vivo modelling of the airflow dynamics and two- and three-dimensional biomechanical effects of suture placements for prosthetic laryngoplasty in horses. Am J Vet Res. 2020;81(8):665672. doi:10.2460/ajvr.81.8.665

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 24.

    Kenny M, Cercone M, Rawlinson JJ, et al. Transoesophageal ultrasound and computer tomographic assessment of the equine cricoarytenoideus dorsalis muscle: relationship between muscle geometry and exercising laryngeal function. Equine Vet J. 2017;49(3):395400. doi:10.1111/evj.12561

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 25.

    Chalmers HJ, Yeager AE, Cheetham J, Ducharme N. Diagnostic sensitivity of subjective and quantitative laryngeal ultrasonography for recurrent laryngeal neuropathy in horses. Vet Radiol Ultrasound. 2012;53(6):660666. doi:10.1111/j.1740-8261.2012.01974.x

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 26.

    Pekarkova M, Kirhcer PR, Konar M, Lang J, Tessier C. Magnetic resonance imaging anatomy of the normal equine larynx and pharynx. Vet Radiol Ultrasound. 2009;50(4):392397. doi:10.1111/j.1740-8261.2009.01555.x

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 27.

    Geng B, Pham N, Xue Q, Zheng X. A three-dimensional vocal fold posturing model based on muscle mechanics and magnetic resonance imaging of a canine larynx. J Acoust Soc Am. 2020;147(4):25972608. doi:10.1121/10.0001093

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 28.

    Erath BD, Plesniak MW. An investigation of jet trajectory in flow through scaled vocal fold models with asymmetric glottal passages. Exp Fluids. 2006;41:735748. doi:10.1007/s00348–006–0196–8

    • Crossref
    • Search Google Scholar
    • Export Citation

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Computed tomographic geometrical analysis of surgical treatments for equine recurrent laryngeal neuropathy

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  • 1 Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
  • | 2 Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, SK, Canada

Abstract

OBJECTIVES

To characterize the 3-D geometry of the equine larynx replicating laryngeal hemiplegia and 4 surgical interventions by use of CT under steady-state airflow conditions. Secondly, to use fluid mechanic principles of flow through a constriction to establish the relationship between measured airflow geometries with impedance for each surgical procedure.

SAMPLE

10 cadaveric horse larynges.

PROCEDURES

While CT scans were performed, inhalation during exercise conditions was replicated for each of the following 5 conditions: laryngeal hemiplegia, left laryngoplasty with ventriculocordectomy, left laryngoplasty with ipsilateral ventriculocordectomy and arytenoid corniculectomy, corniculectomy, and partial arytenoidectomy for each larynx while CT scans were performed. Laryngeal impedance was calculated, and selected cross-sectional areas were measured along each larynx for each test. Measured areas and constriction characteristics were analyzed with respect to impedance using a multilevel, mixed-effects model.

RESULTS

Incident angle, entrance coefficient, outlet coefficient, friction coefficient, orifice thickness, and surgical procedure were significantly associated with upper airway impedance in the bivariable model. The multivariate model showed a significant influence of incident angle, entrance coefficient, and surgical procedure on impedance; however, the orifice thickness became nonsignificant within the model.

CLINICAL RELEVANCE

Laryngeal impedance was significantly associated with the entrance configuration for each procedure. This suggested that the equine upper airway, despite having a highly complex geometry, adheres to fluid dynamic principles applying to constrictions within pipe flow. These underlying flow characteristics may explain the clinical outcomes observed in some patients, and lead to areas of improvement in the treatment of obstructive upper airway disease in horses.

Abstract

OBJECTIVES

To characterize the 3-D geometry of the equine larynx replicating laryngeal hemiplegia and 4 surgical interventions by use of CT under steady-state airflow conditions. Secondly, to use fluid mechanic principles of flow through a constriction to establish the relationship between measured airflow geometries with impedance for each surgical procedure.

SAMPLE

10 cadaveric horse larynges.

PROCEDURES

While CT scans were performed, inhalation during exercise conditions was replicated for each of the following 5 conditions: laryngeal hemiplegia, left laryngoplasty with ventriculocordectomy, left laryngoplasty with ipsilateral ventriculocordectomy and arytenoid corniculectomy, corniculectomy, and partial arytenoidectomy for each larynx while CT scans were performed. Laryngeal impedance was calculated, and selected cross-sectional areas were measured along each larynx for each test. Measured areas and constriction characteristics were analyzed with respect to impedance using a multilevel, mixed-effects model.

RESULTS

Incident angle, entrance coefficient, outlet coefficient, friction coefficient, orifice thickness, and surgical procedure were significantly associated with upper airway impedance in the bivariable model. The multivariate model showed a significant influence of incident angle, entrance coefficient, and surgical procedure on impedance; however, the orifice thickness became nonsignificant within the model.

CLINICAL RELEVANCE

Laryngeal impedance was significantly associated with the entrance configuration for each procedure. This suggested that the equine upper airway, despite having a highly complex geometry, adheres to fluid dynamic principles applying to constrictions within pipe flow. These underlying flow characteristics may explain the clinical outcomes observed in some patients, and lead to areas of improvement in the treatment of obstructive upper airway disease in horses.

Supplementary Materials

    • Supplementary Figure S1 (PDF 278 KB)

Contributor Notes

Corresponding author: Dr. Tucker (michelle.tucker@usask.ca)