SX DX’S OF THE EAR Flashcards
How does the tympanic bulla in a cat differ from a dog?
Cats have a septum that may prevent drainage and cause middle ear infections
List what structures are housed in the external, middle and internal regions of the ear
External: Pinna, auditory meatus, short canal
Middle: tympanic membrane, auditory tube, tympanic cavity
Inner: Bony labyrinth, semicircular canals, stapes, incus, malleus
Aural Hematomas are secondary to __ or ___ and cause a soft swelling of __ fluid in the pinna. What are three treatment options?
Aural Hematomas are secondary to trauma or head shaking from otitis and cause a soft swelling of hemorrhagic or serosanguinous fluid in the pinna.
Treatment options include : drainage with intralesional steroid injections, closed suction drainage or surgical drainage with suture placement
Explain treating an aural hematoma by drainage with close suction drain
The lesion would be injected with triamcinolone or Dexmethasone, a drain placed and bandaged to the head.
Explain how you would treat an aural hematoma by drainage with suture
Incise over swelling then remove all of the fluid and fibrin. Then you leave the incision open removing a 2mm strip and suturing to oppose all layers of the skin, cartilage, skin
You’re treating an aural hematoma and want to make multiple holes with a biopsy punch to drain it. what should you take into consideration?
The vessels of the the ear generally run vertical so its important that your sutures run parallel to the blood supply to avoid trapping the vessels
Squamous Cell Carcinoma is most common in __ and typically locally invasive to the ___ cartilage with treatment being a partial or total __ or cryosurgery, laser ablation, chemo/radiation.
Squamous Cell Carcinoma is most common in cats and typically locally invasive to the articular cartilage with treatment being a partial or total pinectomy or cryosurgery, laser ablation, chemo/radiation.
What is the most common feline cutaneous neoplasm?
Basal cell tumor
Hemangiomas are more common __ and usually __ induced
Cats, UV-B
__ are the 2nd most common feline cutaneous neoplasm and should be removed with 2cm margins, once fascial plane +/- chemotherapy
Mast cell tumors
Indications for surgical intervention of otitis externa
The infection is chronic, end stage and failed medical therapies. On otoscopic evaluation there are hypertrophic tissues, stenotic canal. You should purse imaging to evaluate the bulla and do a cytology and culture.
Radiographs are good for visualizing the __ and _ while CT is useful for ___ especially the __
Radiographs are good for visualizing the external canal and bulla while CT is useful for all portions especially the middle ear
Lateral ear canal resection
This is for mildly infected patients to improve ventilation and reduce secretions. The vertical canal is is cut down, resected and closed. Overall it improves the ability for meds to get where you want.
Indications and contradictions for lateral wall resection
Indications: congenital canal stenosis, small tumors around tragus
Contradictions: end stage otitis externa, horizontal canal stenosis
Vertical ear canal resection
Indicated when there is irreversible hyperplasia/otitis, severe trauma or neoplasia. This makes a hole that is more proximal by incising with a T and making flaps from the canal
Indications for total ear ablation
Unresponsive chronic otitis, stenotic canals, disease extending into the middle or inner ear, failed previous resections, neoplasia
__ and __ are the most common indications of total ear canal ablation in cats
Inflammatory polyps and neoplasia
In a TECA the __ nerve may be involved and should be avoided during surgery if possible. What are some side effects of this nerves involvement?
Facial -> facial drooping, inability to blink, secondary dry eye, elevated 3rd eyelid, sunken eyes
If performing a TECA and lateral bulla osteotomy on a cat what should you consider?
Cats have the septum in their bulla so once you get in and clean the epithelium out of the first chamber you need to break through to the second also
Feline Inflammatory Polyps are typically in the __ or __ . How would you treat each of these
Nasopharyngeal -> traction removal
Bulla -> Ventral bulla osteotomy
Indications and complications of ventral bulla osteotomy
Indications: non- responsive to medical management, involvement limited to the middle ear
Complications: horners syndrome, vestibular signs, hearing loss
What structures should you be concerned about when performing a ventral bulla osteotomy?
Hypoglossal n and lingual facial vein
What are you taking out during a ventral bulla osteotomy?
Epithelium and the mass
What signs might you expect with otitis interna and how might you treat?
Vestibular signs and a ventral bulla osteotomy
Give antibiotics and possibly corticosteroids
