Lecture 11: Laryngeal Paralysis (Exam 2)

Question 1

Define laryngeal paralysis

Answer 1

Complete or partial failure of the arytenoid cartilages & vocal fold to abduct during inspiration

Question 2

What nerves innervate the larynx

Answer 2

• Vagus
• Cranial laryngeal
• Recurrent laryngeal
• Caudal laryngeal

Question 3

What can cause upper respiratory obstruction & mild to severe dyspnea

Answer 3

• Dysfunction of laryngeal muscle
• Dysfunction of recurrent laryngeal or vagus n
• Cricoarytenoid ankkylosis

Question 4

What is laryngeal stridor

Answer 4

• Atrophy of the crocoarytenoideus dorsalis m causes cartilage to remain paramedian during inspiration
• Prevents maximal air intake & increasing airflow, the narrow rima glottidis increases resistance to airflow & creates turbulence giving rise to laryngeal stridor

Question 5

What causes acquired laryngeal paralysis

Answer 5

Damage to the recurrent laryngeal nerve or intrinsic laryngeal muscles

Question 6

What is GOLPP

Answer 6

• Geriatric onset laryngeal paralysis polyneuropathy
• Proposed as a more accurate term for dogs w/ acquired laryngeal paralysis where other causes have been ruled out

Question 7

What signalment is seen w/ laryngeal paralysis

Answer 7

• Common in large breed dogs
• Males are affected two to four time more often than female
• Acquired idiopathic is common in middle aged or older dogs
• Dogs w/ unilateral laryngeal paralysis are rarely symptomatic
• Congenital laryngeal paralysis should be suspected in young large breed dogs w/ upper airway obstruction

Question 8

Describe laryngeal paralysis in cats

Answer 8

• Uncommon
• Clinical sx is similar to a dogs
• Unilateral laryngeal paralysis can present w/ significant clinical sx
• Cause is unknown but associated w/ trauma, neoplastic invasion, & iatrogenic damage

Question 9

What do px w/ laryngeal paralysis freq have

Answer 9

• Progressive inspiratory stridor
• Voice change
• Exercise intolerance

Question 10

Px w/ laryngeal paralysis may have

Answer 10

• Increased stridor
• Dyspnea
• Cyanosis
• Coughing
• Gagging
• Vomiting
• Restlessness
• Anxiety

Question 11

Which animals w/ laryngeal paralysis are @ risk for aspiration of food & saliva

Answer 11

All animals

Question 12

What will be seen in a PE

Answer 12

• Nonspecific
• Labored breathing
• Cont. panting
• Hyperthermia
• Muscle wasting
• Weakness
• Neuro signs

Question 13

What diagnostic imaging should be done

Answer 13

• Lateral cervical & thoracic radiographs
• Laryngeal paralysis cannot be dxed radiographically
• Ultrasound can be used to eval laryngeal fxn

Question 14

What are the warnings to consider when correcting laryngeal paralysis

Answer 14

• Can result in devastating/life threatening aspiration
• Assess pre op esophageal fxn
• Even dogs w/ substantial esophageal dysfunction may have no evidence of esophageal dilation & no H/O regurgitation

Question 15

Describe a laryngoscopy

Answer 15

• Req induction of light general ax
• Laryngeal motion must be compared w/ the phase of respiration for interpretation
• Intubation should be delayed to facilitate exam
• A norm larynx max abducts during inspiration
• In affected dogs the laryngeal cartilages are not located i a paramedian position & do not abduct during inspiration
• Paradoxical vocal fold movement can occur
• Fluttering of the vocal folds & arytenoid cartilages must not be mistaken for purposeful abduction

Question 16

What medical management is done for mildly affected dogs

Answer 16

• often don’t req tx if they have sedentary lifestyle
• Avoid excessive weight gain & stress

Question 17

What is the medical management for small dogs

Answer 17

More successfully managed w/ medical therapy than large dogs

Question 18

What is some medical management for acute resp distress

Answer 18

• Improve ventilation
• Reducing laryngeal edema
• Min the animal’s stress

Question 19

Which surgical tx is the treatment of choice

Answer 19

Unilateral arytenoid lateralization

Question 20

Describe a permanent tracheostomy

Answer 20

Considered a salvage procedure for dogs most @ risk of aspiration pneumonia but is associated w/ a high rate of major & minor complications & req diligent post op & long term care

Question 21

Describe the most common surgical tech

Answer 21

• Involves suturing the cricoid cartilage to the muscular process of the arytenoid cartilage
• Mimics the directional pull of the cricoarytenoid dorsalis m & rotates the arytenoid cartilage laterally

Question 22

What is another name for unilateral arytenoid lateralization

Answer 22

Laryngeal tie back sx

Question 23

How is a laryngeal tie back sx performed

Answer 23

• Larynx is exposed via lateral sx approach
• Separate the cricothyroid & cricoarytenoid articulations
• Place suture from the muscular process of the arytenoid to the dorsocaudal aspect of the cricoid or thyroid cartilage
• Tie the suture w/ enough tension to abduct the arytenoid cartilage mod

Question 24

Describe post op care & assessment

Answer 24

• Give analgesics as needed
• Impaired glottic fxn may persist
• Exercise restriction for 6 to 8 W
• Barking min
• Occasional coughing can occur
• Bark is expected to be quiet & hoarse

Question 25

What are some early complications of suture lateralization

Answer 25

* Hematoma formation * Swallowing discomfort * Temporary glottic impairment * Incisional issue * Coughing after eating & drinking

Question 26

What are some complications

Answer 26

* cartilages may be insufficiently mineralized to retain sutures * Older dogs may fracture or avulse the muscular process & cause failure of abduction & recurrence of clinical sx * 10 to 20 % experience aspiration pneumonia

Question 27

What factors are associated w/ a high risk of aspiration pneumonia

Answer 27

* Increasing age * Temporary tracheostomy * Progressive neuro dx * Post op megaesophagus * Esophageal dx * Concurrent neoplastic dx * opioids given post op

Question 28

Describe the prognosis after unilateral lateralization

Answer 28

* Mild or no clinical sx @ rest do well w/out sx * Mod to severe clinical sx may dev laryngeal collapse & acute resp obstruction * Prognosis after lateralization is good

Question 29

Describe a permanent tracheostomy

Answer 29

* Creation of a stoma in the ventral tracheal wall by suturing tracheal mucosa * Rec for animals w/ upper respiratory obstruction causing mod to severe respiratory distress that cannot be successfully treated by other methods

Question 30

what are the steps of a permanent tracheostomy

Answer 30

* Deviate trachea ventrally apposing the sternohyoid m horizontal mattress sutures dorsal to trachea, excise rectangular segment ventral tracheal wall * I shaped incision is made in the mucosa after the cartilage segment is removed * Excise loose skin adjacent to the stoma * Use intradermal sutures to appose skin to the annular ligs & peritracheal tissues * Complete closure w/ a simple continuous pattern

Question 31

What should owners be warned about w/ a permanent tracheostomy

Answer 31

* Restrict swimming * Vocalization is diminished or absent * Increased risk for resp infections * Ongoing care of the site is necessary

Question 32

What are the key points of laryngeal paralysis

Answer 32

* Etiology of laryngeal paralysis * Unilateral arytenoid lateralization is the treatment of choice * Most common complication is aspiration pneumonia * Permanent tracheostomy is best for cases that are high risk for aspiration pneumonia