Lecture 16: Surgery of the Ear (Exam 3)

Question 1

What should the owner be aware of before surgery & why

Answer 1

• Be aware of the dog’s hearing deficits
• Reduces owner dissatisfaction associated w/ any perceived hearing loss after sx

Question 2

When should pain management be used

Answer 2

It should be fully integrated into every phase of dx, tx, & recovery

Question 3

T/F: Sicker patients may need additional monitoring

Answer 3

True

Question 4

What are the three parts of the ear

Answer 4

• Inner ear (membranous & bony labyrinth for hearing & balance)
• Middle ear (tympanic cavity that connects to the pharynx)
• External ear (the auditory meatus & a short canal

Question 5

Describe the feline tympanic cavity

Answer 5

• Divided into two compartments by a thin bony septum that arises along the cranial aspect of the bulla & curves to attach to the midpoint of the lateral wall

Question 6

What can occur to the postganglionic sympathetic nerves in a feline ear

Answer 6

B/c of their vulnerable location they are often traumatized during surgical curettage of the feline middle ear causing horner’s syndrome

Question 7

What are the most common clinical signs of horners syndrome

Answer 7

• Drooping of the eyelid on the affected side (ptosis)
• The pupil of the affected eye will be constricted (miosis)
• The affected eye often appears sunken (enophthalmos)
• Prominent third eye lid

Question 8

What clinical signs are associated w/ facial nerve paralysis

Answer 8

• Diminished palpebral reflex
• Widened palpebral fissure
• Drooping of the ear & lip
• Excessive drooling
• Blepharospasm
• Elevation & wrinkling of the lip
• Caudal displacement of the labial commissure
• Elevation of the ear on the affected side

Question 9

What can cause facial nerve paralysis & horner syndrome

Answer 9

• Otitis interna
• Otitis media
• Surgery

Question 10

What are the indications of a lateral ear canal resection in patients

Answer 10

• Minimal hyperplasia of the ear canal epithelium
• Small neoplastic lesions of the lateral aspect of the vertical canal

Question 11

When is owner satisfaction lower

Answer 11

When lateral ear canal resection is performed for chronic otitis externa in dogs

Question 12

What is the zep procedure

Answer 12

Modification of the original tech of a lateral ear canal resection, & restricts hair growth @ the horizontal canal opening

Question 13

What should the owner understand about a lateral ear canal resection

Answer 13

That lateral ear canal resection is not a cure & that medical management of the ear probably will be necessary for the remainder of the animal’s life

Question 14

When is a vertical ear canal ablation performed

Answer 14

When the entire vertical canal is diseased but the horizontal canal is norm

Question 15

When is a vertical ear canal ablation the tech of choice

Answer 15

• When neoplasia is confined to the vertical canal
• In some animals w/ chronic otitis externa

Question 16

T/F: Lateral ear canal resection may provide a better cosmetic appearance of the ear than a vertical ear canal ablation

Answer 16

False: a vertical ear canal ablation may provide a better cosmetic appearance of the ear

Question 17

Why should a bulla osteotomy (LBO) be performed in conjunction w/ a TECA otitis externa & media

Answer 17

• Most animals w/ severe chronic otitis externa have concurrent otitis media
• Removing the avenue for drainage of exudative material by performing a TECA w/out treating the otitis media is disastrous

Question 18

Why should a TECA-LBO not be performed on animals w/ mild disease or by surgeons unfamiliar w/ the anatomy of the ear

Answer 18

B/c of the potential for serious complications

Question 19

What is the tech of choice when middle ear neoplasia is suspected in cats that have nasopharyngeal polyps

Answer 19

Ventral bulla osteotomy

Question 20

What does a ventral bulla osteotomy allow

Answer 20

Allows both bullae to be opened w/out the need to reposition the animal

Question 21

What may impair respiration particularly after bilateral TECA & lateral bulla osteotomy

Answer 21

Bandages or excessive swelling

Question 22

What should cat owners be warned about after a ventral bulla osteotomy

Answer 22

Horner’s syndrome & facial nerve paralysis are common but both are transitory

Question 23

What are complication of TECA-LBO

Answer 23

• Intraoperative arterial hemorrhage (life threatening)
• Superficial wound infection
• Facial nerve paralysis
• Vestibular dysfunction
• Deafness
• Avascular necrosis of the skin of the pinna
• Chronic fistulation or abscessation

Question 24

What is the prognosis of facial nerve paralysis

Answer 24

• Usually resolves w/in a few weeks of sx
• Reported to occur in 56% of cats after TECA
• Permanent in approx 1/4th of them

Question 25

What is an aural hematoma

Answer 25

A collection of blood w/in the cartilage plate of the ear

Question 26

What is the most common cause of aural hematomas

Answer 26

Usually secondary to otodectes cynotis

Question 27

What should be done before correcting aural hematomas

Answer 27

The underlying disease must be IDed & treated to reduce the likelihood of recurrence

Question 28

What does the common treatment of aural hematomas involve

Answer 28

* Incising the tissue overlying the hematoma * Evacuating blood clots & fibrin * Holding the cartilage in apposition until scar tissue can form

Question 29

What is an alternative method for treating aural hematomas

Answer 29

Placement of a drain or cannula to provide drainage for several weeks during healing

Question 30

What is important to remember about aural hematoma sx

Answer 30

* S shaped incision made on the concave surface * Incision extends from end to end of the hematoma * Sutures are parallel to the major vessels (vertical) * Leave no pockets to collect fluid * Do not ligate visible branches of the great auricular artery * Do not suture the incision closed

Question 31

Describe Neoplasia of the pinna & external ear canal

Answer 31

* Relatively uncommon in dogs & cats * Can be benign or malignant * Most common are form the ceruminous glands * More aggressive in cats than dogs * Often associated w/ otitis externa, media, interna

Question 32

What is the most important aspect of sx for ear neoplasms

Answer 32

Achieving wide margins to prevent local recurrence

Question 33

When should adjunctive therapy be considered

Answer 33

When aggressive surgical therapy cannot provide clean margins

Question 34

What type of margins should be used when excising malignant ear tumors? What should the owner be advised of?

Answer 34

* Should be excised w/ wide margins of norm tissue * Owners should be advised of the resulting cosmetic defect before sx is planned

Question 35

Describe the surgical technique for small tumors on the central portion of the convex surface of the pinna

Answer 35

* Resect the neoplasm & mobilize the skin around the defect by undermining btw/ the cartilage & the skin * Suture the skin margins or if necessary leave the defect open to heal by secondary intention under a light bandage

Question 36

Describe the prognosis of various ear neoplasms

Answer 36

* Malignant ceruminous gland tumors - ablation is seldom curative * Squamous cell carcinoma - common to not obtain wide margins; prognosis is poor when found in the middle or inner ear * Mast cell tumor - aggressive in the pinnae & may req chemotherapy post op * Aural cholesteatoma in the bullae - May be curative but recurrence is seen w/ advanced dx

Question 37

Describe SCC of the Pinna in cats

Answer 37

* Most common tumor of the pinna in cats * Usually in older cats * Particularly white cats or cats w/ a lack of protective pigmentation of the ear pinna * Solar radiation is a causative factor * Highly invasive * Metastasis is uncommon * May be noted on the nares & eyelids

Question 38

Describe inflammatory polyps

Answer 38

* Second most common cause of nasopharyngeal disease in cats * May occur in dogs but much more common in cats * Cause is unknown * Tends to occur in young cats ( < 2 YO)

Question 39

What may be seen in the Hx & PE of a cat w/ inflammatory polyps

Answer 39

* Most cats present for eval of dysphagia or upper respiratory signs * They may present for signs of otitis externa * May be presented for acute onset of head tilt, nystagmus, &/or vestibular imbalance * Clinical sx may be present for months before eval * Most are unilateral * Usually have upper respiratory obstructive signs

Question 40

What imaging is the most useful for dxing nasopharyngeal polyps

Answer 40

Lateral radiographic images of the pharyngeal region

Question 41

What is the gold standard for determining the extent of involvement & whether the nasopharyngeal polyps are unilateral or bilateral

Answer 41

CT

Question 42

When are the best results seen when performing surgical tx for polyps

Answer 42

* When a ventral bulla osteotomy is performed * Recurrence rate is less than 2%

Question 43

When should ventral bulla osteotomy be performed

Answer 43

Allway be performed if middle ear disease is evident on radiography or CT

Question 44

What is the prognosis of polyp

Answer 44

* Excellent w/ complete removal of the poly p * Nasopharyngeal polyps may be less likely to recur than aural ones * Horner's typically resolves w/in a few weeks * Rarely temporary or permanent vestibular signs may occur * Transient facial nerve paralysis is uncommon * Unlikely to affect hearing * Polyp recurrence & long term adverse effects are rare