Week 1 - URT Surgery in Small Animals Flashcards
What does BOAS stand for?
Brachycephalic obstructing airway disease
What are primary causes of BOAS?
Primary = born with
Stenotic external nares
Relative overlength of the soft palate
Relative oversize of the tongue
Tracheal hypoplasia/stenosis
Sliding hiatal hernia
What are secondary causes of BOAS?
Secondary = consequence of airway obstruction
Hypertrophy of the soft palate
Tonsillar hypertrophy
Everted laryngeal ventricles/saccules
Laryngeal collapse
Pharyngeal collapse
Glosso-epiglottic mucosa displacement
Scrolling of epiglottic cartilage
Vomiting/regurgitation
Is there a grading system for BOAS?
Yes
Owners want vet to be aware of this and provide advice on breeding. The lower the score, the better!
What is tracheal hypoplasia?
Narrowing of the trachea
Primary cause of BOAS
Animals can present with no clinical signs.
What is the medical management for BOAS?
Weight loss
Reduction of exposure to heat, short regular exercise rather than long walks and over-excitement
Harness rather than collar
What are the surgical options for BOAS?
Nasal wedge-resection
Alar fold resection for stenotic nares
Partial staphylectomy of the soft palate
Folded-flap palatoplasty
Tonsillectomy (normally done alongside above options)
How does laryngeal collapse occur?
When there is an obstruction in the airway, the diaphragm and intercostal muscles have to work harder and generate a larger inter-thoracic negative pressure.
This affects the structure in which air passes through and if the structures are flexible, then they can collapse.
Is laryngeal collapse staged?
Yes - there are three different stages
1 = laryngeal sauce eversion
2 = medial deviation of the cuneiform cartilage and aryepiglottic fold or aryepiglottic collapse
3 = medial deviation of the cuneiform cartilage and aryepiglottic fold or aryepiglottic collapse
How can laryngeal collapses be managed?
Surgically - excision of everted laryngeal saccules
What is this problem and how can it be fixed?
Primary BOAS = external nasal aperture stenosis
Surgical management
- Rhinoplasty (wedge-resection)
- Alar fold resection
What are the surgical options to correct the soft palate?
Partial staphylectomy
Folded-flap palatoplasty
What is the normal movement of the arytenoid cartilage on inspiration and expiration?
Inspiration – cartilages are abducted
Expiration – cartilages are adducted (air break)
Expiration at exercise – cartilages are abducted
What is laryngeal paralysis and what causes it?
The nerves and muscles that control the movements of one or both arytenoid cartilages of the larynx cease to function, and instead of opening during aspiration and closing during swallowing, the arytenoids remain stationary in a somewhat neutral position.
What are the clinical signs of laryngeal paralysis?
Stridor
Cough
Dyspnoea
Change in phonation (bark)
Exercise intolerance
Collapse
Signs worse with severity and when dog is hot, excited or exercised.
How do you diagnose laryngeal paralysis?
Characteristic clinical signs
Auscultation of the larynx and the thorax
Laryngoscopy (under a light plane of general anaesthesia)
Straight-bladed laryngoscope (Miller)
Wha should you also check when dealingg with laryngeal paralysis?
Survey inflated radiographs of the thorax
Neurological examination
Routine haematology and blood biochemistries
Thyroid function testing?
Animals are often older when present so should look for concurrent disease as well:
- Cardiac
- Lower respiratory tract
- Dysphagia
- Megaoesophagus
- Hypothyroidism
What is emergency medical management can be done in laryngeal paralysis?
Rest (calm – both dog and owner)
Supplemental oxygen
Cooling
Sedation
Intravenous access
Intravenous corticosteroids (?)
Last resort:
Anaesthetise => tracheostomy tube placement (?)
What is the surgical option for laryngeal paralysis?
Arytenoid lateralisation (tieback)
Aims to widen the rima glottdis and prevent dynamic collapse of the arytenoid cartilage
Performed as unilateral procedure
(dogs present bilateral, cats present unilateral)
What are the post-op requirements after surgery to fix laryngeal paralysis?
Observe feeding and drinking (aspiration risk)
Strict rest for 2-3 weeks
Antibiotics
Analgesics
Harness
What complications could there be after surgery to fix laryngeal paralysis?
Seroma formation
Aspiration pneumonia
Inadequate lateralisation
Suture failure/recurrence
Change in bark
In the right hands, surgical outcome is general very good
Owner will me most aware of change in bark -> worn them!
What is tracheal collapse and which breed is most disposed to it?
A condition of excessive collapsibility of the trachea which usually results in dorsoventral flattening of the tracheal lumen (trachea becomes flat)
Yorkshire terrier
What are the clinical signs of tracheal collapse?
Classic ‘goose-honk’ cough
Pulling on collar & lead
Exercise
Anything that makes the dog cough
Are tracheal collapses graded?
Yes - graded with an endoscope
Trachea’s will have more than one grade as they will start of normal width, get narrower, return to normal width (e.g. grade normal, 1 ,2 4, 2, normal)
What is the medical management for tracheal collapse?
Antitussives
Bronchodilators
Antibiotics
NSAIDS
Corticosteroids (inhaled) -> prevent side effects
Bronchodilators (inhaled)
What are the surgical options for tracheal collapse?
Open ring prosthesis
Stenting
What are common causes of nasal disease in dogs and how are they investigated?
FB
Tumour
Aspergillosis
Chronic rhinitis
Epistaxis
Investigation
- CT scan
- Rhinoscopy
- Radiography
- Nasal flush
What is the common chronic nasal discharge in cats?
Chronic rhinitis
What happens in chronic rhinitis in cats?
Inflammation and swelling of the conchae
Increased mucus production
Usually secondary infection, mucopurulent secretion may contain blood
Severe inflammation = loss of conchae
Feline herpesvirus 1 could play a role in chronic nasal inflammation, resulting in destructive rhinitis
Which animals commonly present with Fungal rhinitis (Aspergillosis)?
Dogs
Medium to long nose breeds
Less common than neoplasia
What is fungal rhinitis (Aspergillosis)?
Disease generally restricted to nasal cavity and sinuses
But is markedly destructive to turbinates
Can erode frontal bones and cribriform plate
What are the clinical signs of fungal rhinitis (Aspergillosis)?
Nasal discharge
- Mucopurulent
- Unilateral (progrèss to bilateral)
- Intermittent epistaxis
Ulceration or depigmentation of nasal planum
Pain on palpation
Sneezing
Facial deformity?
Neurological signs?
How is fungal rhinitis (Aspergillosis) diagnosed?
History, clinical signs
Blood tests?
- r/o coagulopathy
- Coagulation profile
Diagnostic imaging
- Radiography of nose and sinuses
- CT/MRI
Rhinoscopy
Cytology
Serology?
Look at it -> sample it!
How is fungal rhinitis (Aspergillosis) treated?
Challenging to treat -> needs to be aggressive to be successful
Oral antifungal agents (‘azoles)
- Requires prolonged treatment
- Side effects (anorexia, V+) common
- Not recommended
Topical therapy
- Preferred option
- enilconazole, clotrimazole
Choice of delivery method?
- Catheter placement in frontal sinuses via surgery
- Minimally invasive methods
- Use of debridement
Common to debride and then place catheter to allow continuous delivery of anti-fungals.
