Laryngeal hemiplegia-most common breeds
Thoroughbred, standardbred
Laryngeal hemiplegia
- failure of arytenlid cartilage cornicular process to abduct due to nerve damage and resultant atrophy of CAD muscle
- inspiratory noise only
- vocal cord laxity
consider these things if bilateral paralysis of arytenoid cartilages
arytenoid chondritis, hypertrophic ossification of laryngeal cartilages
laryngeal hemiplegia-definitive dx
only by endoscopy
Aryepiglottic fold envelopes the epiglottis
entrapment of epiglottis
Hitting_____ when tubing horses can cause epistaxis
middle nasal conchae
Nerve damage in guttual pouch produces what clinical sign?
Horner’s syndrome (miosis, ptosis, enopthalmus)
Study findings-LLH
- decreased pH, PaO2
- increased PaCO2
- variable effect on HR
Adductor larygeal muscles
- lateralis
- ventricularis
- transversus
these are NOT affected in LLH
most common cause of LLH
genetic
if laryngeal hemiplegia is on the right side, what are the most common causes?
iatrogenic or infection
muscular process is between what muscles?
cricopharyngeus & thyropharyngeus
Treated with laryngotomy
- arytenoid abnormalities-chondritis
- ventriculectomy & vocal chordectomy
- pharyngeal & laryngeal cyst
- DDSP
- epiglottis entrapment
Most common locations of congenital respiratory cysts
- dorsal pharyngeal
- subepiglottic
Embryonic origin of subepiglottic cysts
thyroglossal duct
Embryonic origin of dorsal pharyngeal cysts
Rathke’s pouch
Embryonic origin of ventricular cysts
parotid gland tissue
Etiologies of DDSP
- increased negative pressure
- nerve damage
- hypoplastic epiglottis
- tranquilizers, twitch
Tie forward
- suture through thyroid cartilage, around lingual process and basihyoid bone, move entire larynx forward and up and epiglottis ends above soft palate
- successful ~50% of the time (other surgeries have similar success)
Tx of epiglottis entrapment
- laryngotomy-aryepiglottic fold resection
- orally-aryepiglottic fold divided with hook knife
- laser-aryepiglottic fold axially divided
How to cut with laser if using a non contact fiber for epiglottis entrapment
cut caudal border to tip
How to cut with laser if using contact fiber for epiglottis entrapment
cut tip to caudal border
Hypoplastic epiglottis is involved in:
- DDSP
- epiglottis entrapment
what do you see with entrapment of epiglottis?
see silhouette but not vascular pattern or scalloped edges
