Surgery of dynamic resp tract disorders

Question 1

What is alar fold collapse and what is the treatment

Answer 1

Where the fold that makes the medial shelf of the flase nostril collapses causing loud vibrating noice
Treat via surgical resection of fols

Question 2

How is respiration in time with locomotor cycle

Answer 2

Expiration when leading leg hits ground in canter
Inspiration when it leaves the ground

Question 3

CLinical signs of cleft palate
What about in those that have survived to adulthood

Answer 3

Nasal return of food, cough after suckling, aspiration pneumonia

IF it survived; intermitten coughing/dyphagia, noise when exercising due to palate flapping around, associated with epiglottic entrapment

Question 4

How to manage adults with cleft palate

Answer 4

Feed from floor
Give antibiotics for aspiration pneumonia when needed

Question 5

What is nasopharyngeal collapse
What horses do we see it in

Answer 5

Neuromuscular dysfunction of walls of pharynx where they come in when horse breathes at exercise
Gives whistling noise

Common in racehorses, fat ponies/cobs
Worse wiht neck/neck flexion e.g in dressage

Question 6

How does dorsal disaplcement of soft palate present

Answer 6

Marked respi obstruction so gurgle noise and rough respiratory noise
Horse will pull up abruptly and try and swallow

Question 7

When do we classically see dorsal dispalcement of soft palate

Answer 7

Racehorses at max exertion
Can see in dressage horses associated with head flexion

Fat ponies

Question 8

What proposed aetiology means we might see DDSP in young racehorses entering training

Answer 8

Due to muscular fatigue of the palate in unfit horsess

Question 9

How do diagnose dorsal displacement of soft palate

Answer 9

Exercising endoscope because this happens only at exercise

Can make presumptive diagnosis based on jockey report

Question 10

Proposed causes of DDSP

Answer 10

• Dysfunction of muscles of soft palate
• Fatigue of muscles of soft palate in unfit horses
• URT inflammation/infectino
• Physical lesions that presipose e.g epiglotti entrapment, cysts etc

Question 11

Conservative treatment strategies for DDSP

Answer 11

Tack changes e.g tongue tie, different nosebands
If young, rest
If unfit, increase fitness
ANti-inflammatories to deal with lwoer rest tract inflammation

Question 12

Two surgeries that are generally both done for DDSP at once

Answer 12

Tie forward to move position of larynx in relation to palate
Palatoplasty to induce fibrous tissue to tighten up the soft palate

Question 13

When can we get persistent DDSP

Answer 13

Rare
May see after surgery for epiglottic entrapment
Usually related to predisposing lesion e.g epiglotic entrapment, sub-epiglottic cyst, epiglottitis

Question 14

What muscle is responsible for abduction of artenoid cartilages laterally and dorsally in exercise

Answer 14

Circoarytenoideus dorsalis

Question 15

Which are the only two laryngeal cartilages that move

Answer 15

Epiglottis
Arytenoids; abduct to open larynx wide during exercise

Question 16

WHen do we see maximal arytenoid abduction

Answer 16

After swallowing
Should indcude this during scoping to assess for degree of laryngeal paralysis

Question 17

What nerve supplies all the intrinsic laryngeal muscles (including cricoarytenoideus dorsalis)

Answer 17

Recurrent laryngeal nerve (branch of vagus)

Question 18

What is the most common cause of recurrent laryngeal neuropathy

Answer 18

Idiopathis
= axonopathy of left laryngeal nerve

Question 19

What horses are affected by idiopathic recurrent laryngeal neuropathy

Answer 19

Tall horses

Question 20

What are some causes of non-idiopathic recurrent laryngeal neuropathy

Answer 20

Perivascular injection of irritant material into neck
Trauma
Systemic disease
Guttural pouch disease

Question 21

Pathophysiology of recurrent laryngeal neuropathy

Answer 21

Neuropathy of left recurrent laryngeal nerve
Causes atrophy of left CAD muscle so can’t abduct cartilage
So get sucking in of left arytenoid towards midline during inspiration +/- prolapse of left vocal fold

Question 22

what noises do we get with recurrent laryngeal neuropathy depending on severity

Answer 22

Inspiratory noise (i.e hear when leading leg leaves ground)

If just vocal fold collapsing hear whistling noise
If whole larynx collapses hear roaring noise

Question 23

Diagnosis of recurrent laryngeal neuropathy

Answer 23

ABnormal inspiratory noise during exercise
May be able to palpate muscular process of arytenod cartilage more prominent on the left due to wastage of CAD

Question 24

What grade of recurrent laryngeal neuropathy definitely needs a tie back

Answer 24

Grade 4
= complete hemiparesis with no movement

Question 25

how does RLN grading system wokr

Answer 25

= done during quiet breathing and used to predict likelihood to affect exercise
1 = perfect symmetry and syncrhony
4 = complete hemiparesis with no movement

Question 26

Treatment options for recurrent laryngeal neuropathy

Answer 26

Vocal cordectomy + ventriculectomy = using laser to cut out vocal fold
–> Done when vocal fold prolapsing but arytenoid cartilage maintains some abduction; generally only in low level work

Prostethic laryngoplasty = tie back; treatment of choice for performance horses or severe cases
Suture muscular process of arytenoid to back of cricoid to mimic action of CAD; keeps left arytenoid in permanently open position

Question 27

What is arytenoid chondritis and how do we treat

Answer 27

= infection of one/both arytenoid cartilages; get swollen, distorted cartilage which may have granuloma
Rare in UK
Mostly young male TBs

Treat medically with systemic antibiotics and atni-inflammatories long term; can do throat sprays of steroid

Surgery = partial arytenoidectomy to resect some of cartilage

Question 28

If we palpate a gap between thyroid and cricoid cartilages what does this mean

Answer 28

4th branchial arch defect
Congenital disorder affecting derivatives of emryonic 4th branchial arch

Question 29

What are the derivatives of embryonic 4th branchial arch

Answer 29

Thyroid cartilage, cricoid, cricpharyngeal muscle (upper oes sphincter), crico-thyroideus mm

Question 30

What is the most common cause of right sided laryngeal dysfunction

Answer 30

4th branchial arch defect
(can also occur on the left or bilaterally but then other things more common )

Question 31

Signs with 4th branchial arch defect

Answer 31

Abnormal noise at exercise
Exercise intlerance
Aerophagia since missing upper oesophageal sphincter; can manifest as chronic colic

Question 32

Diagnostic features of 4th branchial arch defect

Answer 32

Palpate gap b/w thyroid and cricoid
Endoscopy; reduced arytenoid function, rostral displacement of palatopharyngeal arch
Xray: air column in prox oes; aerophagia

Question 33

What is the most common abnromality on exercising endocopy; causes high pitched inspiratory whistle

Answer 33

Medial deviation of ary-epiglottic folds

Question 34

Treatment of medial deviation of ary-epiglottic folds

Answer 34

Trim the folds using endoscopic laser to remove excess tissue

Question 35

Treatment of epiglottic entrapment

Answer 35

Divide membrane iwth hooker knife under standing sedation

Question 36

How can we tell there is epiglottic entrapment

Answer 36

Can’t see blood vessels and serated edges as seen on normal epiglottis

Question 37

WHat is epiglottic retroversion

Answer 37

Intermitten sucking back of epiglottis into rima glottis causing intermittent tinspiratory obstruction and gulping noise

Question 38

Treatment of epiglottic retroversion

Answer 38

Epilottic tie down surgery

Question 39

Which animals so we see tracheal collapse in

Answer 39

Small breed horses/pnoes

Question 40

Why do we ge trahceal collapse

Answer 40

Due to instability of dorsal ligament of the trachea usually with chondromalacia of tracheal cartilages

Question 41

Treatment of tracheal collapse

Answer 41

try to manage medically by treating any LRT issues
No good surgery

Question 42

What is cobblestone tissue at back of mouth on endoscope mean

Answer 42

Pharyngeal lymphoid hyperplasa
Can be normal to see when young racehorses all brought into training together

Question 43

Exercising abduction grades for RLN

Answer 43

A = fine
B = vocal fold collapse, gives whistle sound
C = laryngeal arytenoid collapse; gives roaring sound