Otic surgery Flashcards
Draw a diagram of the external ear?
Draw a diagram of the inner and middle ear of a dog?
What are the Primary causes of Otitis Externa?
- Parasites
- Otodectes cynotis
- Demodex canis/cati
- Sarcoptes scabiei
- Notoedres cati
- Cheyletiella spp
- Hypersensitivity and allergic disease
- Hypothyroidism
- Keratinization disorders
- Autoimmune disorders
What are the Predisposing causes of Otitis Externa?
- Anatomic and conformational factors
- Excessive moisture
- Iatrogenic factors
- Obstructive ear disease
What are perpetuating causes of otitis externa?
Bacteria (Staph. Intermedius, Pseudomonas aeruginosa, Proteus mirabilis, Escherichia coli, Corynebacterium spp, Enterococcus spp, Streptococcus spp)
Yeast (Malassezia pachydermis, Candida spp)
Otitis media
Progressive pathologic changes
What are the major indications for ear surgery?
- Trauma (mainly pinna but sometimes external ear canal)
- Aural haematoma
- Neoplasia (pinna, external ear canal, middle ear, etc.)
- Certain cases with chronic otitis externa
- Chronic otitis media
- Infection (extension of chronic otitis externa)
- Middle ear polyps
- Cholesteatoma
What are the most common neoplasms of the pinna?
What has this cat been treated for?
Surgical management of pinnal squamous cell carcinoma
White cats have a tendency to develop these as their pinna tips/extremities are sensitive to UV rays.
What is an aural haemotoma?
Bleed between scafa (aural cartilage) and integument
- The aetiology of aural haematoma remains unknown
- Proposed associations have included:
- Otodectes cynotis
- Otitis externa
- Trauma
- Autoimmunity
- Hypersensitivity
More common on just the medial aspect in dog.
How are aural haematomas managed?
- Surgical incision, drainage, and suture
- Drainage with an indwelling drain (Penrose, tube, teat tube, etc.)
- Drainage and glucocorticoid instillation
- Closed-suction drainage
- Surgical incision, drainage, and suture
Picture shows: Stitch the integument and skin to cartilage to cause adherence and heal by scarring.
How should stitches be placed when fixing an aural haematoma?
Be aware of blood supply best to put them in they way shown above so you don’t occlude the blood vessels.
How is a teat tube placed to treat an aural haematoma?
What are the complications of drainage of aural haematomas?
- Cosmetic alterations
- Recurrence of haematoma
- Pinna necrosis
Outline surgical management of Otitis Externa (procedures performed on external ear canal)?
Lateral wall resection
Vertical canal ablation
LWR is indicated in the following circumstances?
- Persistent, or recurrent, otitis externa with mild, potentially reversible, hyperplasia of the epithelium and adnexae
- Neoplasia of the lateral wall of the vertical canal
- Very rarely in the management of otitis media to facilitate flushing and drainage of the bulla
Name neoplasias of the external ear canal?
What is this?
Ceruminous gland adenoma on left & adenocarcinoma on right
What is a lateral wall resection and when can it be performed?
- The procedure does not cure the animal of its underlying disease but improves the micro-environment of the ear
- LWR will fail if there are chronic, irreversible, hyperplastic changes to the luminal epithelium or if there is ongoing otic inflammation
- Removing the lateral wall of the vertical portion of the external ear canal.
- Has been used to treat otitis externa but most causes of this are allergy and if you don’t treat the underlying cause not much use of doing this surgery as the problem will persist.
What are some complications of lateral wall resection?
Not very effective for most ear disease we see.
- Postoperative pain/discomfort
- Incisional dehiscence
- Persistent otitis externa
- Persistent, unrecognised otitis media
- Failure to provide adequate drainage of the horizontal canal
What are complications of vertical canal ablation?
- Postoperative pain/discomfort
- Incisional dehiscence
- Persistent otitis externa
- Persistent, unrecognised otitis media
- Stenosis of horizontal canal
- Facial paralysis
What is the most like causative agent of this infection?
That looks like malassezia
What is the most like causative agent of this infection?
Prominent purelent one. Most likely pseudomonas
What are the classic features of Horner’s syndrome are:
- Anisocoria (pupils unequal size)
- Ptosis of the upper eyelid
- Narrowing of the palpebral fissure
- Enophthalmos
- Protrusion of the third eyelid
VBO is indicated in cases with middle ear disease and the following circumstances:
Photos show structures you must move out of the way to get access to it.
Cases in which a TECA is not required
Certain brachycephalic breeds of dog
Often used in the cat
- Anatomy of the bulla
- Inflammatory polypoid disease in the absence of chronic otitis externa
What is this?
Cholesteatoma
Slowly enlarging, cystic lesions within the middle ear cavity
Lined with stratified squamous epithelium and keratin squames
Thought to arise when a pocket of the tympanic membrane comes into contact with, and adheres to, inflamed mucosa within the middle ear.
Treatment – TECA BO or VBO
What can be seen here?
Inflammatory polyps in cats
- Aetiology unknown (early exposure to cat flu??)
- Often emanate from tympanic bulla
- Nasopharyngeal
- Horizontal ear canal
- Otitis media
- Start point commonly in middle ear: then they can grow one of two ways–> towards pharynx or–>external ear canal
- Cats often present if polyp in pharynx as diff breathing.
- Do not forget to examine the ear canals in cases of nasopharyngeal polyps and the nasopharynx in cases of polyps in the external ear canal
What is seen here?
Primary Secretory Otitis Media
- Obstruction to the auditory tube means middle cannot drain properly. SO they end up with a bulging tympanic membrane as seen from an otoscope.
- Cavalier King Charles spaniels
- Syringomyelia (Chiari-like malformation of the calvarium/caudal fossa)
- Commonly bilateral
- Affected dogs will have reduced hearing
- Bulging pars flaccida
- Myringotomy + flushing of affected tympanic bulla
- May require multiple treatments
