Disorders of the Larynx and Pharynx

Lecture 34

What condition is defined as the failure of arytenoid cartilages to abduct during inspiration, whcih creates an upper airway obstruction?

laryngeal paralysis

Abductor muscles of the arytenoid cartilages are innervated by?

right and left recurrent laryngeal nerves

Which species most often presents with clinical signs of laryngeal paralysis?

dogs

List potential causes of laryngeal paralysis.

idiopathic

ventral cervical lesion (trauma to nerves, neoplasia, other inflammatory/mass)

anterior thoracic lesion (neoplasia, trauma, post op)

polyneuropathy and polymyopathy (idiopathic, immune mediated)

endocrinopathy (hypothyroidism)

toxicity

congenital disease

myasthenia gravis

What breeds are predisposed to congenital laryngeal paralysis?

Bouvier des Flandres

Siberian Huskies

Bull Terriers

Idiopathic laryngeal paralysis is part of a generalized neuromuscular or polyneuropathy complex, which means what?

these dogs will demonstrate signs of generalized neuromuscular disease/neuropathy within 1-2yrs and it is important for owners to know that laryngeal paralysis is a progressive disease

What are the hallmark signs of laryngeal paralysis?

respiratory distress and stridor

What is the most common signalment associated with laryngeal paralysis?

older, large breed dogs (Labs overrepresented)

How do dogs often present with laryngeal paralysis?

in an acute respiratory crisis requiring emergency intervention with a history of gagging or coughing, especially when eating or drinking

How can we diagnose laryngeal paralysis?

Workup: PE, ortho/neuro exam, CBC, Chem, UA, thyroid profile; thoracic radiographs +/-neck

laryngeal exam under light sedation (propofol or alfaxolone, no pre med) —> laryngoscopy

What percentage of laryngeal paralysis dogs are also hypothyroid?

30%

What rule outs are there for laryngeal paralysis?

pharyngeal and esophageal dysmotility

megaesophagus

How can we treat laryngeal paralysis?

emergency management of airway obstruction

sedation with acepromazine, butorphanol, or buprenoprhine IV

provide cool, O2 rich environment

short acting glucocorticoids (dexamethasone) IV

evaluate for surgical management once stable —> unilateral arytenoid lateralization (“tie back”)

What is a contraindication of performing unilateral arytenoid lateralization (“tie back”) for treating laryngeal paralysis?

megaesophagus

If surgery for treatment of laryngeal paralysis is not an option, how can we medically manage the condition?

± corticosteroids to reduce inflammation

weight management

exercise / heat restriction

walking in harness vs collar

What is the most common complication associated with laryngeal paralysis?

aspiration pneumonia

What drug can be given pre op to help reduce the incidence of aspiration in laryngeal paralysis cases?

cisapride

What breeds are commonly affected by Brachycephalic Airway Syndrome?

Boston Terriers

Pugs

Bulldogs

French Bulldogs

Himalayan cats

What are the most common presenting complaints from owners with dogs affected by Brachycephalic Airway Syndrome?

Stertor (snorting, snoring breathing)

GI signs of vomiting and regurgitation are often also present

What are the 4 components of Brachycephalic Obstructive Airway Syndrome (BOAS)?

stenotic nares

elongated soft palate

hypoplastic trachea (Bulldogs)

everted laryngeal saccules

What procedure can be performed to open stenotic nares?

alarplasty

What procedure can be performed to resect elongated soft palate?

staphylectomy

List clinical signs of Brachcephalic Airway Syndrome.

signs are caused by impaired air flow through the upper airways and increased intrathoracic pressure

loud upper airway noise (stertor, snoring) associated with obstruction primarily during inspiration

cyanosis, syncope

GI signs of vomiting and regurgitation

How can we diagnose Brachycephalic Airway Syndrome?

based on breed, clinical presentation

cervical and thoracic radiographs to evaluate structure and presence of secondary disease (pneumonia)

visual exam of oropharynx / larynx via scoping

How can we treat Brachycephalic Airway Syndrome?

enhance passage of air through limited airways by minimizing stress factors and surgical correction of abnormalities

perform surgical procedures early at 3-4 months of age before signs develop

Which laryngeal neoplasia is most common in cats?

lymphoma

List clinical signs associated with laryngeal neoplasia.

consistent with upper airway disease —> noisy respiration, stridor, increased inspiratory efforts, change in voice

mass lesions can cause dysphagia, aspiration pneumonia, palpable mass

How can we diagnose laryngeal neoplasia?

diagnostic imaging —> radiographs, CT/MRI, laryngoscopy

FNA and biopsy for histopathology

How can we stage malignant laryngeal neoplasia?

local lymph node evaluation

thoracic radiographs

What laryngeal neoplasia can be seen on this cytology?

squamous cell carinoma

How can we treat laryngeal neoplasia?

Palliative only NOT curative and dependent on tumor type

surgical excision, laryngectomy with permanent tracheostomy

radiation therapy

chemotherapy if lymphoma

NSAIDs targeting COX 2 inhibition can slow progression

What are different types of laryngeal neoplasia?

carcinomas (squamous cell, undifferentiated, adenocarcinoma)

lymphoma

melanoma

mast cell tumor

benign neoplasia