BOAS: Post-Surgical Assessment, Refractory Cases and Cats

Question 1

Best way to audit BOAS post surgery?

Answer 1

If you have assessed your dogs according to the respiratory function grading (RFG) scheme (discussed in lesson 1) prior to surgery, then you can audit the surgical effectiveness by repeating RFG assessments after surgery

Question 2

Why do days 7-14 days post surgery increase regurgitation; therefore making BOAS assessment tricky? (2)

Answer 2

Increases due to:
- Anaesthetic
- Stress

Question 3

Why do we now split surgeries in extreme brachycephalics if they are elective and perform airway surgery first and then come back for neutering or cruciate surgery or skin fold surgery?

Answer 3

complications post-surgery and anaesthesia are linked to duration of anaesthesia

Question 4

When to reassess BOAS post surgery so that swelling can resolve, and the airway can stabilise?

Answer 4

6-8 weeks

Question 5

What should be encouraged alongside surgery, particularly in Pugs?

Answer 5

Weight loss

Question 6

If GI signs persist post sx and there is still nasal obstruction, what technique can be used?

Answer 6

Laser assisted turbinectomy

Question 7

BOAS surgery mortality rate? Why?

Answer 7

1.6-5%
(regurg –> aspirate)

Question 8

What grade laryngeal collapse is associated with a poorer prognosis?

Answer 8

2+3

Question 9

Possible deadly complication of BOAS surgery?

Answer 9

Aspiration pneumonia

Question 10

Laryngeal paralysis:
Define grade 1

Answer 10

Everted laryngeal ventricles/saccules.

Question 11

Laryngeal paralysis:
Define grade 2

Answer 11

Collapse of the cuneiform processes of the arytenoids.

Question 12

Laryngeal paralysis:
Define grade 3

Answer 12

Collapse of the corniculate and cuneiform processes of the arytenoids.

Question 13

What is the difference between pug and french/english bulldog arytenoid cartilage.

What is the consequence of this?

Answer 13

Pug cartilage is softer

• Changes in the Bulldogs tend to be later stage and more severe.

Question 14

Laryngeal saccules, what are they:
A) Medial to?
B) Lateral to? (2)

Answer 14

A) Thyroid cartilage
B) Vocal and vestibular folds

Question 15

Describe why laryngeal eversion is the first stage of laryngeal collapse.

Answer 15

As the saccules are the place of least resistance in the wall of the larynx and therefore evert under the action of negative pressure.

Question 16

Why is laryneal regression theoretically possible with laryngeal eversion?

Answer 16

Cantatore in 2012 found a chronic lymphoplasmacytic inflammation in the everted ventricles.

Question 17

The histological features were actually unchanged if the saccules were resected months apart suggesting once the ventricles evert the process is non-reversible:

What is the proposed theroy?

Answer 17

once a saccule is everted and swollen, the compression at its base might interfere with lymphatic return, preventing spontaneous resolution

Question 18

Which breed with BOAS is more likely to have everted saccules?

Answer 18

Pugs

Question 19

How is a sacculectomy performed?

Answer 19

Sacculectomy is performed by removing the ventricle at the base with scissors (a diode laser can be used)

Question 20

Why is it difficult to get a good visualisation in sacculectomy?

Answer 20

BOAS dogs often have redundant pharyngeal tissue that swells rapidly with minimal handling

Question 21

Scissors advised for a sacculectomy?

Answer 21

Microvascular scissors which are 20 cm long with a delicate cutting tip.

Question 22

Describe ET tube for sacculectomy including reducing aspiration risk.

Answer 22

slightly smaller ET tube than normal

• nudge the ET tube dorsally to access the ventricles – i.e. we are not extubating to remove the ventricles.

Question 23

In grade 2-3 laryngeal paralysis, what else is removed at time of sacculectomy?

Answer 23

laryngeal arytenoid cuneiform process

Question 24

What are the benefits of removing laryngeal arytenoid cuneiform (2)

Answer 24

• less tissue that can be sucked into the rima glottidis on inspiration and appears
• aid stabilisation of the larynx.

Question 25

We will also do cuneiformectomy at this stage, but this requires ? in Bulldogs and increases the chance of placing a tracheostomy.

Answer 25

bipolar electrosurgery

Question 26

Stage 2 laryngeal collapse; what technique?

Answer 26

partial laryngeal resection can be performed (an aryepiglottic fold resection with removal of the cuneiform process)

Question 27

Stage 3 laryngeal collapse; what technique?

Answer 27

The larynx can be opened with a left-sided cricoarytenoid lateralisation combined with thyroarytenoid caudo-lateralisation (arytenoid laryngoplasty).

Question 28

What is different with a laryngeal resection when comparing to normal laryngeal lateralisation?

Answer 28

• cartilages are mobilised more (cricoid thyroid disarticulation),
• arytenoid is moved more caudally and secured between the thyroid and cricoid.

Question 29

What are requirements of permanent tracheostomy to bypass upper airways?

Answer 29

• Trim hair around stoma
• Clean environment
• Daily cleaning

Question 30

Another more recently reported surgical technique that addresses the nasal obstruction is?

Answer 30

Laser assisted turbinectomy (LATE)

Question 31

Laser assisted turbinectomy (LATE):
A) Decreases nasal resistance by?
B) What pre-op imaging is needed? (3)

Answer 31

A) 60%
B) CT, rhinoscopy and plethysmography

Question 32

Laser assisted turbinectomy (LATE):
A) What should be done first in BOAS dogs?
B) When is it perfromed? (2)

Answer 32

A) Traditional sx; nares, tonsils, palate
B) aberrant nasopharyngeal turbinates or excessive nasal turbinates, if the response to the first surgery is disappointing

Question 33

What is the aim of Laser assisted turbinectomy (LATE)?

Answer 33

produce a clear ventral passage through the nasal cavity into the nasopharynx

Question 34

Which “clinical signs” dogs response well to Laser assisted turbinectomy (LATE)? (How does this commonly present (3)

Answer 34

Those with obvious nasal/nasopharyngeal obstruction.

(Common presentation - sleep disorder + regurg, when exercise; open mouth quickly)

Question 35

Common post op complications of Laser assisted turbinectomy (LATE)?

Answer 35

Reverse sneezing

Question 36

What can be used in each nostils prior to trubinectomy shrinks the nasal mucosa and reduces bleeding?

Answer 36

0.2 ml xylometazoline (Otrivin)

Question 37

0.2 ml xylometazoline (Otrivin)
Onset time?

Answer 37

3mins

Question 37

0.2 ml xylometazoline (Otrivin);
A) Receptor?
B) Where does it selectively work?

Answer 37

A) Alpha 3 agonist
B) Nasal mucos

Question 38

How many dogs are classified as clinically unaffected after LATE?

Answer 38

80%

Question 39

What aspect of BOAS may LATE not improve?

Answer 39

improve clinical signs but often does not resolve airway noise.

Question 40

What should an O look into if wants a brachy beed?

Answer 40

Kennel Club Assured Breeders scheme
Health tested their breeding stock
Discourage online purchase
Watch parents (+exercise)

Question 41

Brachycephalic cat breeds? (3)

Answer 41

Persian, Burmese, Himalayan.

Question 42

Common obstruction site in cats?

Answer 42

Nostrils (elongated soft palates are documented)

Question 43

Clinical signs of BOAS in cats? (4)

Answer 43

exercise intolerance
Upper airway noise
excessive inspiratory times
abdominal effort .

Question 44

First surgical technique to use in cats? (which method?

Answer 44

Nostrils first (Trader technique with a beaver blade)

Question 45

What surgery is progressed to in cats not responding to nostril surgery?
Where is it performed
compare to dogs?

Answer 45

Staphylectomy
mid tonsillar level

(more cautious than the dog