Surgical Dz of the Upper Airway Flashcards
What is the best modality to evaluate nasal disease
Computed Tomography
Rhinoscopy and Nasopharyngoscopy should be performed Before or After imaging?
Rhinoscopy and Nasopharyngoscopy should be performed AFTER imaging.
What should you PCR for in the nasal cavity?
Bartonella and Mycoplasma
A dog has neoplasia/Squamous Cell Carcinoma on its nose. What type of surgery is indicated in this dog?
Nasal Planum Resection
What anatomical defect causes Brachycephalic Airway Syndrome
Local chondrodysplasia which results in early ankylosis of basioccipital and basisphenoid bones
What are the primary disease components of the brachycephalic airway syndrome ?
- stenotic nares
- elongated soft palate
- everted laryngeal saccules/Stage I Laryngeal Collapse
- Hypoplastic trachea
What are the contributing problems to the Brachycephalic Airway Syndrome
- nasopharyngeal turbinates
- Stage 2 or 3 laryngeal collapse
- tonsillar eversion
- tracheal collapse
- secondary edema
- macroglossia
What is the pathophysiology of Upper Airway Obstruction Disease
Higher negative pressures to overcome obstruction –> Secondary soft tissue changes - edema ,hyperplasia and collapse –> Decreasead air flow with increased obstruction
What is the most common component of Brachycephalic Airway Syndrome?
Elongated Soft Palate
What does the Elongated Soft Palate cause?
Mainly inspiratory dyspnea - stertor
Describe the Stages of Laryngeal Collapse
Stage 1 - everted laryngeal saccules
Stage 2 - collapse of the cuneiform cartilage
Stage 3 - collapse of the corniculate cartilage
Which breed of dogs is the most affected by hypoplastic trachea?
English Bulldogs
What is hypoplastic trachea?
Irregular thick/firm cartilage rings
- overlap of rings
- increased airflow resistance
Describe the cardiovascular changes seen with Brachycephalic Airway Syndrome
Chronic decreased PaO2 secondary to airway obstruction –> Pulmonary vasoconstriction –>V/Q mismatch –> Subsequent vasoconstriction/hypertension
This eventually leads to coronary pulmonale and right heart failure
A 2-3 year old, male English Bulldog presented with upper airway issues. What is the most likely diagnosis
Brachycephalic Airway Syndrome
For Brachycephalic Airway Syndrome, you want to stop the negative effects before it progresses.
Truth
Describe the clinical presentation of an aymptomatic BAS dog
- affects very young animals
- less severely affected animals and often owners are NOT appreciating the clinical signs present
Describe the clinical presentation of a mild/moderate BAS dog
- Exercise intolerance
- Increased noise - ‘snoring’, ‘snuffing’ and reverse sneezing
Describe the clinical signs of a SEVERE BAS dog
Present on an emergent basis in ACUTE RESPIRATORY DISTRESS
- severe upper airway swelling, hyperthermia and cyanosis
What are the differential dx for BAS?
Space occupying mass of the upper airway
- neoplasia
- abscess
- granuloma
- FB
- Epiglottic retroversion
What are the drugs that must be avoided when doing a tracheostomy/endoscopy?
- Ketamine
- Diazepam / Midazolam
- Large doses of pure mui agonists
These drugs have been known to result in a lack of abduction
What are the drugs that should be used when performing a tracheostomy / endoscopy>
Propofol +/- Butorphanol or Buprenorphine
Can utilize Doxapram to improve the strength of respiration
It is important to use the same or similar protocol every time
When is surgery necessary for a BAS dog?
When any of the components of BAS is present
- upper airway exam should be recommended for any brachycephalic dog at the time of spay/neuter
- It is important to surgically intervene if indicated to prevent any secondary changes.
What are the 3 types of surgical procedure that can alleviate Brachycephalic Airway Syndrome?
- Wedge resection
- Soft palate resection
- Excision of the everted laryngeal saccules
It is important to provide GI protectants and promotility agents for 10-14 days pre-op to decrease aspiration pneumoniae. T/F
TRUTH
When is Dexamethasone indicated pre-operatively?
Soft palate resection / everted saccule excision
Describe the three tyoes of resection possible for soft palate resection
Sharp dissection
CO2 laser excision
Bipolar sealing excision
What is the landmark that is used for the soft palate resection?
TONSILLAR CRYPTS - caudal third of the tonsil to middle third of the tonsil
When is Unilateral Arytenoid Lateralization indicated ?
Only seen in cases of laryngeal PARALYSIS
What is the analgesic that can be provided post op?
Buprenorphine - not an overly painful procedure
What is the most concerning post -op complication in BAS dog ?
Aspiration Pneumonia
What is the surgical treatment for epiglottic retroversion?
Surgical pexy of the ventral aspect of the epiglottis and the dorsal base of the tongue.
Which intrinsic muscle is responsible for laryngeal abduction?
Cricoarytenoideus dorsalis
Which nerve is responsible for the failure of laryngeal abduction?
Caudal laryngeal nerve - motor nerve
In laryngeal dz, the dyspnea that occurs does not improve with open mouth breathing. T/F
TRUE
What is the etiology of laryngeal paralysis ?
Dysfunction/damage to the vagus nerve and its branches (recurrent laryngeal and caudal laryngeal nerves) that affects the function of the cricoarytenoideus dorsalis muscle.
This results in the failure of arytenoid to abduct on inspiration
A 11 week old Rottweiler presents with ataxia, paresis, head tremors and neurogenic muscle atrophy. What is the most likely diagnosis
Congenital Laryngeal Paralysis which is a progressive generalized degenerative dz.
What is the poster child of the IDIOPATHIC LARYNGEAL PARALYSIS ?
Labrador !
What are the possible causes of Idiopathic Laryngeal Paralysis?
Idiopathic - most common Hypothyroidism Trauma Immune mediated (myasthenia gravis) Infectious Toxins (lead, organophosphates)
How many thoracic radiographic views should you take if you suspect laryngeal paralysis ?
3 views
What is the treatment of choice for moderate to severe laryngeal paralysis ?
Surgery - UNILATERAL ARYTENOID LATERALIZATION - widening the rima glottidis
What is the Poiseuille’s Law?
Resistance to flow is inversely proportional to the radius.
What is one of the primary clinical signs of aspiration pneumonia?
HYPERTHERMIA
The primary complication of Unilateral Arytenoid Lateralization?
Aspiration Pneumoniae
What is ventriculocordectomy in layman terms ?
Debarking or Devocalization
Is the ventriculocordectomy done ventrally or dorsally?
Transoral and ventral approach
