Large Animal Respiratory Surgery (PART2) Flashcards
How many arytenoid cartilage are there?
2 Left and right
List the respiratory cartilages that make up the Larynx
- arytenoid
- epiglottis
- thyroid cartilage
- cricoid
List the muscular structures that make up the larynx
-cricoarytenoideus DORSALIS
What is the cricoarytenoideus dorsalis muscle innervated by?
Recurrent laryngeal nerve
How many ventricles are there?
2 left and right ventricle
The vocal fold is the entrance to the__________
Lateral ventricles
T/F: the soft palate of the horse is normally tucked under the epiglottis
TRUE
What is the other name for recurrent Laryngeal Hemiplagia?
ROARER
What is recurrent laryngeal hemiplagia?
- Uni (bi) lateral paralysis of the cricoarytenoideus muscle
- Progressive neurogenic atrophy (distal axonopathy) of the recurrent laryngeal nerve (branch of vagus)
What muscle is paralyzed in Recurrent Laryngeal hemiplagia?
Roarer
CRICOarytenoid muscle
Which side is most commonly affected in Roarers?
Recurrent laryngeal hemiplagia
LEFT side more common
What is the incidence of recurrent laryngeal hemiplagia?
- 1-10 years old
- Large breed horses
- Thoroughbred yearling sales
- hereditary
Is recurrent laryngeal hemiplagia hereditary?
Yes, it can be passed on
- Not always
What is the most common cause for upper respiratory NOISE in the HORSE?
Recurrent laryngeal Hemiplagia
What are the Etiologies for Recurrent Laryngeal Hemiplagia?
- Perivascular injection (Left Jugular vein)
- Gutteral pouch mycosis
- Trauma
- Strangles
- Organophosphate toxicity
- Plant poisoning
- Lead toxicity
- CNS disease
- Liver Disease
How would you diagnose recurrent laryngeal hemiplagia?
1) history
- noise
- exercise intolerance
2) Palpation
- LEFT side bulge
3) Endoscopy
- Slap test
- Videoendoscopy during treadmill exercise
What is the “Slap test”
Diagnostic test to evaluated Recurrent Laryngeal Hemiplagia
1) slap withers during endoscopy
2) observe ADDuction of contralateral arytenoid cartilage
What is the Pathway being tested during slap test?
Slap on right side
-nerve impulse through:
SPinal Cervical cord—>medulla decussation (cross over)—>recurrent laryngeal Nerve LEFT side
What is the grading system for Recurrent laryngeal hemiplegia ?
Grade 1 - Normal full ABDuction of both
Grade 2- Asynchronous ABduction, but full abduction CAN be achieved
GRADE 3- Asmmetry at rest, some movement but full abduction CANNOT be achieved
Grade 4- Asymmetry at rest and no movement
What makes the noise during recurrent laryngeal hemiplegia?
The collapsing of the arternoid cartilage during INSPIRATION
Roaring, from laryngeal hemiplegia is a ______________ respiratory Noise
INSPIRATORY
What treatment can be done for Recurrent Laryngeal Hemiplegia?
1) Laryngoplasty(TieBack)
Laryngoplasty is also called__________.
TieBack
What position is the horse placed in for laryngoplasty (TieBack) surgery?
Right lateral recumbency
-because the paralysis’s is normally on the left side
How does the Laryngoplasty (tie back) work?
Want to mimic the cricoarytenoid dorsalis muscle
1) suture in the cricoid (do not penetrate lumen of trachea)
2) one suture Under Cricopharyngeus muscle
3) second suture end under cricopharyngeus muscle.
4) dissect muscular process of arytenoid cartilage
- pulls arytentoid cartilage back with suture
The skin incision for laryngoplasty is made _________ to the ______________vein.
Ventral
Lingual facial vein
What are the complications of TIE BACL (laryngoplasty) surgery?
1) prosthesis failure
2) loss of abduction
3) SEROMA
4) Cough (remove suture)
5) Dysphagia
What other surgery is usually combine with the Tie back, to correct Roarers?
Recurrent laryngeal hemiplagia (roarer)
VENTRICILECTOMY
Sacculoectomy
What is ventriculectomy?
Remove the ventricles
-usually done in combo with laryngoplasty (TieBack)
What type of retractors are used for ventriculectomy?
Weitlaner retractor
What is the roaring bur used for?
- insert into ventricle
- exteriorize ventricle
- remove BOTH ventricles
Ventriculectomy (to treat Roarers)
What are the complications of Ventriculectomy?
1) GRANULOMA formation
2) mucocele
3) laryngeal web
What is a more natural way of treating recurrent laryngeal hemiplegia (roarers)?
Neuromuscular pedicle graft
-to reinnervate the CRICOarytenoid muscle
Why did the Neuromusclar pedicle graft not catch on in AMERICA to fix recurrent laryngeal hemiplagia?
Because it take about a year to re-innervate
- the horse owners cant wait that long (peak performance is gone)
When would you perform an Arytenoidectomy?
1) arytenoid chondropathy
2) Laryngeal hemiplegia
3) failed laryngoplasty
What is arytenoid chondritis?
Inflammation and thickening of the arytenoid cartilage
How would you treat arytenoid chondritis?
Arytenoidectomy
1) total: arytenoid body, corniculate and muscular process
2) Partial: arytenoid body and corniculate process
What is the preferred treatment for arytenoid chondritis?
PARTIAL Arytenoidectomy
-body and corniculate process
What is the RTR for Partial Arytenoidectomy?
50%
-significantly improved upper airway flow dynamics
What is Dorsal displacement of the soft Palate (DDSP)
When the soft palate is displaced OVER the epiglotis
Why does “choking up “ happen?
When the soft palate displaces dorsally
Where should the soft palate be normally in relation to the epiglottis?
Ventral / below epiglottis
We should always be able to see the epiglottis on endoscopic view!!!!!
What is the conservative treatment options for DDSP?
- NSAIDs
- Tongue Tie
- Laryngohyoid support divice
How does the tongue tie treat DDSP?
Prevents horse from moving the larynx caudally
How does the laryngohyoid suppport device work for DDSP?
Moves the larynx CRANIALLY
What are the surgical options for treatment of DDSP?
1) Staphylectomy
2) Myectomy
3) Epiglotic augmentation
4) Laster cauterization
5) Laryngeal Tie forward
What muscles are involved in Myectomy as a treatment for DDSP?
1) sternothyroideus
2) sternohyoideus
3) omohyoideus
How does laser cauterization treat DDSP?
Laser epiglotic fold
- scar tissue forms
- tightens epiglotis folds
What is the best surgical treatment for DDSP?
Laryngeal tie forward
What is a staple lot you?
Remove 5cm off caudal edge of soft palate
How does the Tie forward treat DDSP?
Pulls the larynx cranially, so soft palate cant displace anymore
-pulls thyroid cartilage cranially
What is epiglotic entrapment?
Loose/too much mucosa below epiglotis
-cover the tip of the epiglotis
How do you treat epiglotic entrapment?
Transaxial division
What is used to cut the epiglotic fold, during epiglotic entrapment treatment?
BISTOURY
