Surgical Diseases of the Ear

Question 1

ID

Answer 1

1. Medial border of helix
2. Apex
3. Lateral border of helix
4. Scapha
5. Antihelix
6. Antitragus
7. Tragus
8. Intertragic Incisure

Question 1

What nerves supply motor vs. sensory to external ear?

Answer 1

Motor = facial (CN7)
Sensory = vagus (CN10)

Question 2

Arterial supply to ear canal

Answer 2

Great auricular artery- branch off external carotid

Question 3

Pinna

Your feline patients got into a scuffle with its other housemate cat and suffered lacerations to its pinna. How would you treat this wound?

Answer 3

1. Anesthetize cat and clean/prepare wound for cutaneous sx
2. Suture the skin only via simple interrupted appositional sutures

Question 4

Pinna

How would you treat a small mass wound that is close to the margins of the lateral border of the helix?

Answer 4

Via wedge excision or partial pinnectomy

Question 5

Pinna

Describe drainage with close-suction active drain for auricular hematoma tx

Answer 5

1. Remove a butterfly catheter’s adapter end and create small fenestrations into tube’s free end
2. Insert free end into hematoma via stab inision and suture into place via purse-string and fingertrap suture
3. Poke needle into vacuum blood tube to create constant suction

Question 6

Pinna

Describe incisional drainage for auricular hematoma tx

Answer 6

1. Incise all over swelling
2. Remove any clots & fibrin
3. Place staggering parallel rows of full-thickness (skin, cartilage, skin) interrupted mattress sutures over entire abnormal region of the pinna, PARALLEL to the vascular supply

PARALLEL b/c pinnal necrosis can ensue if vasculature is occluded

Question 7

Pinna

What drug can you inject into an auricular hematoma cavity following drainage?

Answer 7

Methylprednisolone (0.5-1.0cc)

Question 8

Pinna

Why is it imperative to bandage a dog’s ear after hematoma drainage?

Answer 8

Bandage compresses pinna against auricluar cartilage to prevent further trauma from shaking and head-shaking

Question 9

Pinna

Raised or erosive painful lesion that is locally invasive into the auricular cartilage

Answer 9

Squamous Cell Carcinoma - cats > dogs

Cats w/ SCC present w/ bleeding, cracked, non-healing wounds of the ear margins

Question 10

Pinna

How can SCC be treated (3)?

Answer 10

Options:
1. Partial pinnectomy
2. Total pinnectomy
3. Pinnectomy + vertical canal ablation when lesions are extensive

Question 11

Pinna

UVB-induced neoplasia of the pinna

Answer 11

Hemangioma and hemangiosarcoma
- most common in light-colored cats

Question 12

Pinna

Prognosis for hemangiosarcoma tx in cats?

Answer 12

Surgical excision median disease-free interval = 9.5mo

Question 13

Pinna

Most common feline cutaneous neoplasm
- what does the lesion look like?
- Tx?

Answer 13

Basal Cell Tumors
- small, slow-growing, well-demarcated
- raised, white-to-hyperpigmented nodules
- Surgical excision is usually curative

Question 14

Pinna

2nd most commonly dx cutaneous tumor in cats

Answer 14

Mast Cell Tumors
- those involving the pinna account for 59% of all MCTs arising in head region
- benign, well-circumscribed, discrete lesions

Question 15

Pinna

How are MCTs treated?

Answer 15

Wide incisions needed to cure: 2cm margins (one fascial plane deep)
- Pinna: longitudinal pinnectomy (peripheral mass) or total pinnectomy (central mass)

Question 16

External ear canal

When is surgical intervention indicated for otitis externa/media?

Answer 16

Chronic, end-stage infections that have failed medical therapies

Normal ears: Staphylococcus, Pseudomonas, Streptococcus, Proteus spp.

Pathologic populations: S. intermedius or pseudintermedius, P. aeruginoas, Proteus mirablilis, E. coli, Cornyebacterium spp., Entercoccus spp., and Streptococcus spp.

Yeast infection: overpopulation of commensal Malassezia pachydermatis

Question 17

External ear canal

Otoscopic findings in otitis externa?

Answer 17

Proliferative changes in epithelial lining of ear canal
- hyperkeratinization
- hyperplasia of sebaceous and ceruminous glands
- infiltration w/ inflammatory cells -> stenotic canals, fibrosis, mineralization -> occlusion

Question 18

External ear canal

Why is imaging of tympanic bulla important in otitis externa evaluation?

Answer 18

To evaluate for tympanic membrane rupture, a common sequela to severe otitis externa that will progress to otitis media and interna if untreated

Question 19

External ear canal

ID the issue

Answer 19

otitis media
- fluid filling the right tympanic bulla w/ an intact tympanic membrane + small accumulation of fluid in left bulla

Question 20

Sx of the external ear

Goals of Lateral EAR CANAL (wall) resection (3)

Answer 20

“Zepp Procedure”

1. Improve ventilation at the corner of the “L”
2. Reduce secretions, serve as prevention
3. Medical Mgmt: will help reduce the frequency of infection by improving the structure of the external canal and by allowing easier access to the ear for routine ear cleaning and treatment with medicine

Question 21

Indications for lateral EAR CANAL (wall) resection (3)

Answer 21

1. Congenital canal stenosis
2. small tumors at/near tragus
3. early OE

Question 22

Contraindications for lateral ear canal (wall) resection sx (2)

Answer 22

1. end-stage OE
2. horiztonal canal stenosis

Question 23

Vertical canal ablation (vertical ear canal resection) indications (3)

Answer 23

Performed when the vertical ear canal is severely diseased but the horizontal is unaffected (RARE- seldomly performed)
1. Hyperplastic otitis
2. Severe truama
3. Neoplasia

Question 24

TECA/Total ear canal ablation: indications (4)

Answer 24

1. Failed tx via ear canal resection 2. Extension of disease into middle ear 3. Unresponsive to chronic OE due to stenotic canals 4. Mgmt. of ceruminous gland adenocarcinomas

Question 25

What structure do you need to be cautious of when performing TECA?

Answer 25

**Facial nerve**- monitor for signs of **facial nerve paralysis** post op (inability to blink, drooping ear, drooping upper lip, drooling from one corner of mouth, decr. tear production -> dry eyes)

Question 26

What is the #1 disease indicating TECA sx in cats?

Answer 26

Inflammatory polyps (60%)

Question 27

Why is lateral bulla ostetomy (LBO) often performed in conjunction w/ TECA?

Answer 27

Secretory events of the ear begin in the bulla, and move up ear via "secretory escalator". If TECA performed, these secretory contents have nowhere "up" to go, so need to create opening to allow for drainage - RECALL that cats have two separate chambers per bulla while dogs only have one, so need to cut into BOTH for cats!

Question 28

What is the #1 cause of otitis media in cats?

Answer 28

Inflammatory Polyps!! - locations: **bulla** or nasopharynx

Question 29

CS + TX of feline inflammatory polyps based on location

Answer 29

1. **Bulla**: head shake, scratching, OE, Horner's syndrome -> TX = VBO 2. **Nasopharynx**: dyspnea, dysphagia, nasal d/c, sneezing, coughing -> TX = traction removal

Question 30

Ventral Bulla Osteotomy 1. Indications 2. Potential complications post op (3)

Answer 30

1. Feline inflammatory polyp of middle ear 2. Horner's, vestibular signs, hearing loss

Question 31

Tx for otitis interna

Answer 31

establish some form of drainage to the middle ear via VBO, plus ABX and corticosteroids to aid w/ inflammation | OI = inflammation to CN8!