Surgical Diseases of the Ear Flashcards
What is included in the external ear anatomy?
Pinna, auditory meatus and short canal
What is included in the middle ear anatomy?
Tympanic membrane, auditory tube (Eustachian tube), tympanic cavity
What is included in the inner ear anatomy?
Bony labyrinth, semicircular canals, auditory ossicles (stapes, incus, malleus)
What is different in the bulla of cats?
They have 2 compartments vs one as in dogs
What are good suture patterns to use for small lacerations to the ear?
Simple interrupted, figure 8 pattern, vertical mattress
What do you need to worry about when performing mattress patterns?
Proper apposition- don’t want everting or inverting
What is the treatment for deep fissures or small masses at or close to the margins of the ear?
Partial pinnectomy or wedge excision
- concern for vascular supply being compromised
What reconstructive techniques could be considered for larger defects of the ear?
Local transposition flaps, distant pedicle flaps
Define an aural hematoma
Often secondary to trauma the cartilage separates from the underlying skin and fills with either blood or serosanguinous fluid
-there is a theory that animals with autoimmune diseases are predisposed
What is the primary clinical sign for an aural hematoma?
Soft fluctuant swelling +/- pain
What are the options for drainage of aural hematomas
Drainage with intralesional steroids
Closed suction drainage
Surgical drainage with suture placement
Describe the drainage with closed suction technique for aural hematomas?
Drain with large ga needle, flush with saline, +/- inject steroids (monitor for abscess formation), suture drain into place
-90% of patients have resolved signs and cosmetic appearance is maintained
What do you have to consider about the bandage at this location?
You need it to be stiff to reduce movement and recurrence of signs
Describe the drainage with suture placement technique for aural hematomas
Taking out a strip of tissue with scalpel blade to allow for drainage
-incise over swelling
-remove all fluid and fibrin
-leave incision open but tack down skin (oppose all layers)
-can use stents to reduce tension
-must place sutures in parallel to vascular supply
What is a similar alternative to the drainage and suture placement technique?
Biopsy punch
- multiple holes for drainage
-more labor intensive
What is a common cancer in cats that affects the ears?
Squamous cell carcinoma
-raised erosive lesions that are locally invasive in articular cartilage
What is the treatment for squamous cell carcinoma on pinna of cats?
Partial or total pinnectomy +/- ablative procedure, cryotherapy, laser ablation or chemo
What is the etiology behind hemangiomas and hemangiosarcomas on cat ears?
Associated with UV-B exposure
What is the most common feline cutaneous neoplasm?
Basal cell tumors
What is the second most common feline cutaneous neoplasm?
mast cell tumors
What ear neoplasm are orange cats in particular affected with?
Sebaceous adenomas
Define otitis externa
Inflammation of the ear canal
What makes the canine ear particularly prone to otitis?
Its L shape- makes drainage of debris more difficult
-when debris builds up lining of the ear gets inflamed leading to further production of sebum
What breeds are the most predisposed to otitis?
Spaniels, doodles (due to hair in ears), german shepards
When to perform surgery for otitis externa cases?
Chronic end stage infections that have failed medical therapies
-have they seen a dermatologist yet? if not do this first
What is often seen on otoscopic exam in these end stage cases?
Hypertrophic tissues, stenotic canals
What should you do if worried about internal masses after otoscopic evaluation?
Imaging- Radiography, CT
What can the different imaging modalities tell you in chronic otitis cases?
Radiographs: can show you stenosis or mineralization in the external canal. In the bulla can see increased soft tissue opacities, thickening, irregularities or bony lysis
CT: can give you a better image of the inner ear, as well as other portions. Can look for fluid accumulation, soft tissue proliferation, bony lysis or expansion
What is lateral ear canal resection also known as?
A Zepp procedure
What do you use a zepp procedure for?
Mildly affected patients
- owners may be having problems getting drops all the way in
-not showing signs of stenosis
What are the goals of the Zepp procedure?
To improve ventilation, reduce secretions
-medical management still paramount
-eliminates the curve to deal with so can introduce drops more directly into the horizontal canal
Describe vertical ear canal resection
Create a hole directly into the vertical canal
- can use only when horizontal ear canal is clear
-post-op complications are plentiful
What are the indications for total ear canal ablation?
Unresponsive otitis externa with stenotic canals, previous resection failure, or neoplasia
What is removed for total ear canal ablation?
Entire ear canal
- externally, pinna is only thing intact, tragus is gone, meatus is gone
-everything up to the tympanic membrane is removed
What do you have to be careful to avoid with total ear canal ablation?
The facial nerve! Often can’t avoid as its already wrapped up in the infection
- look out for facial drooping, inability to blink, sunken lobes
What always needs to be performed in conjunction with a total ear canal ablation?
A lateral bulla osteotomy
-secretory events start here, if not removed can lead to infection, swelling, redness, irritation, fistulas
What are the main clinical signs associated with otitis media?
Head shaking, scratching, head tilt
What are the clinical signs of feline inflammatory polyps?
Depends on location
If nasopharynx affected will see dyspnea, dysphagia, nasal discharge, sneezing, coughing
If bulla affected will see head shaking, scratching, otitis externa, horners syndrome
What diagnostics should you use to determine if a cat has feline inflammatory polyps?
Physical exam, otoscopic exam, pharyngeal exam, imaging
What is the treatment for feline inflammatory polyps?
If in nasopharynx- traction removal
If in bulla, ventral bulla osteotomy
How do you find the polyp in the nasopharynx when performing nasopharyngoscopy?
Must pull back the soft palate
How do you know that you are not leaving a part of the polyp behind?
Should appear comma shaped (how you know you got the stalk)
Describe the ventral bulla osteotomy
Indicated when infection involvement is limited to the middle ear and canal is unaffected and the lesion is unresponsive to medical management
- must avoid hypoglossal nerve and linguofacial vein
-must remove both the mass and the epithelium
-can place a drain if there was a lot of pirulent debris
-take sample for C/S testing
What are the clinical signs of otitis interna?
Vestibular signs
Treatment for otitis interna?
Ventral bulla osteotomy if inner ear is only area affected
- if nerves affected, may not be able to reverse signs but can make animal feel better
-use antibiotics and steroids post op to help with nerve inflammation
