Upper airway is from _________ to _________.
nares; thoracic inlet
Upper airway obstruction manifests as...
increased inspiratory effort and stridor.
Describe the components of brachycephalic upper airway syndrome. (4)
- stenotic nares
- elongation of the soft palate
- everted laryngeal saccules
- hypoplastic trachea
Laryngeal stenosis is usually a result of... (2)
- de-bark surgery gone wrong
- mass in the larynx
Describe the anatomical changes with stenotic nares (as compared to normal).
cartilaginous plate forming the alar fold is shorter, thicker, and medially/ ventrally displaced--> increased airway resistance on inspiration
What is the surgical technique to treat dorsoventral compression with stenotic nares?
ventral horizontal wedge (excise ventral wedge of nares)
What is the surgical technique to treat medially stenotic nares?
vertical wedge excision of nares- excise vertical wedge then suture the wedge closed, pulling mares laterally
What is a simple and effective way of surgically treating stenotic nares?
4mm punch biopsy in alar fold--> suture closed, pulling nares laterally
What is the normal anatomical alignment of the soft palate?
- lateral free edges form the palatopharyngeal arches
- caudal edge should meet to cover the tip of the epiglottis
- when elevated, soft palate closes off airway when swallowing
- when depressed, palate closes off oral cavity when nasal breathing
Describe elongated soft palate.
caudal free edge of the soft palate is redundant extended beyond the tip of the epiglottis; tis tissue is pulled into the airway lumen (rima glottidis), creating resistance to inflow of air
Describe surgical treatment of elongated soft palate.
- soft palate is trimmed from the junction of the palatopharyngeal arches to create a gentle curve across the center
- close with continuous pattern, suturing oral to nasal mucosa- vicryl or dexon
Describe everted laryngeal saccules.
- mucosal lining of the laryngeal ventricles everts into rima glottidis d/t excessive negative upper airway pressure
- mucosal prolapse physically obstructs airway
- SECONDARY problem
What is the surgical treatment for everted laryngeal saccules?
- excision of saccules from an intra-oral approach
- everted mucosa is retracted medially and excised with metzenbaums at attachment to laryngeal ventricle
Describe tracheal hypoplasia.
- lumenal diameter decreased throughout length of trachea
- limits airway flow
What are complications of upper airway surgery? (5)
- gagging/ coughing
- vomiting/ regurg
- local tissue edema (use steroids post op)
- airway obstruction
- aspiration pneumonia
What is the appropriate post-op care after upper airway surgery? (4)
- endotracheal tube should stay in place as long as possible
- administer anti-inflammatories (steroids- Dexamethasone)
- overnight in ICU
- reduce gastric acid in case of regurg
Describe the anatomy of the larynx.
- cranially- hyoid apparatus and thyrohyoid bone
- caudally- tracheal attachment, cricoid cartilage
- arytenoid cartilages are paired and form the cranial dorsal aspect of larynx, surround rima glottidis- ABDUCTED BY CRICOARYNTENOIDEUS DORSALIS M.
Describe the pathology associated with roarers.
- recurrent laryngeal nerve, which arises from the vagus nerve within the thorax, is the motor innervation to cricoaryntenoideus dorsalis m.
- damage to this nerve- failure to abduct the laryngeal folds/ arytenoid cartilages--> increased airway resistance
What are the types of lar par?
- acquired- traumatic, diffuse neuromuscular, idiopathic**** (most common)
Clinical signs of lar par. (8)
- change or loss of bark
- gagging when eating or drinking
- inspiratory stridor
- decreased activity/ exercise intolerance
- signs worse in hot/ humid weather
What is the risk-benefit debate with surgery to manage lar par?
- you're permanently opening the larynx, so you put the dog at risk for aspiration pneumonia
- for dogs that are severely affected or exercise intolerant and collapsing, surgery is necessary
How do we treat lar par in good surgical candidates?
lateralization of cricoarytenoideus dorsalis and arytenoid cartilage- only do one side!!!!--> gives the dog enough airway so they stop collapsing from hypoxia
What animals are most likely ot get lar par?
older, large breed dogs