Surgery of the ear Flashcards by Rebecca Davies

What does the auricular cartilage form?

Majority of the pinna and all of vertical ear canal

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What are the important ear landmarks?

Helix, antihelix, tragus, antitragus, tragic notches

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What is the function of the scutiform cartilage?

Attaches the auricular cartilage to the head medially

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What is the blood supply to the ear?

Great auricular artery

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Label the landmarks of the ear

IMAGE

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What is an aural haematoma?

Collection of blood within the cartilage plate of the ear from damage to branches of the great auricular artery

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What is the cause of an aural haematoma?

Unknown but possibly from physical injury to the pinnae
Headshaking and ear scratching predispose
Aural inflammation, parasites, allergy and FB are predisposing factors

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What results if an aural haematoma isn’t treated?

Haematoma -> seroma -> fibrosis -> contraction deformity

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What are the treatment aims of aural haematoma?

Address underlying source of infection
Evacuate the haematoma
Prevent recurrence

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What is the process of conservative management of an aural haematoma?

Needle aspiration, pressure bandage and/or continuous drainage through a canula/penrose/closed suction drain for 2-3 weeks

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How is an aural haematoma managed surgically?

Incise concave surface of pinnae
Evacuate the haematoma
Place sutures parallel to major vessels without tension through cartilage and one/both skin surfaces
Don’t suture incision leave open for drainage
Apply a light bandage for several days

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What are the potential complications of aural haematomas?

Recurrence
Cauliflour ear
Abscessation leading to pinnae amputation

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What is a pinnectomy?

Amputation of the pinna

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What are the indications for a pinnectomy?

Solar injury, cold injury, neoplasia, trauma, vasculitis, permanent marking, recurrent (poly)chondritis in cats

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How do feline and canine pinnectomies differ?

In dogs need to ligate vessels before going through cartilage

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How is a pinnectomy performed?

Excise with 1cm margins if neoplastic

Close by primary apposition of skin edges over the amputated cartilage

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What are the clinical signs of middle ear disease?

Facial nerve (VII) paralysis, Horner’s syndrome, head shaking, rubbing/scratching of affected ear, tilting/rotating of head to affected side

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What are the clinical signs of inner ear disease?

Hearing loss, head tilt, circling/leaning/falling to affected side, incoordination, spontaneous horizontal nystagmus

What should be looked at on aural examination prior to surgery?

How stenosed/diseased are the vertical and horizontal canals?
What is the state of the tympanic membrane?
Can you see a mass?

What radiography views should be taken prior to surgery?

DV skull, open-mouth bullae, lateral oblique bullae

What should you look for on radiography of ear canals?

Ear canal stenosis, calcifications, middle ear disease

What is the anatomy of the external ear?

External auditory meatus is opening to ear canal
Vertical ear canal made up of auricular cartilage
Horizontal ear canal made up of annular cartilage
Annular ligament joins vertical and horizontal canals
Lined by stratified squamous epithelium

What is the path of the facial nerve around the ear?

Exits the stylomastoid foramen caudal to the ear and runs ventrolateral in close proximity to the base of the external ear canal/middle ear cavity

What clinical signs result from damage to the facial nerve?

Paresis/paralysis of eyelids and ear if only auriculopalpebral branch
Tear and saliva production decreased

What are the different surgical techniques that can be used to treat endstage OE?

Lateral wall resection Vertical ear canal ablation TECALBO (total ear canal ablation and lateral bulla osteotomy)

What are the aims of a lateral wall resection?

Increase drainage and ventilation of the external ear canal | Decrease moisture, humidity and temperature in the external ear canal

What are the indications for a lateral wall resection?

Otitis externa that has not responded or has recurred despite appropriate medical management

What are the contra-indications for a lateral wall resection?

Chronic, endstage OE Irreversible horizontal canal disease/stenosis Otitis media

What is are the potential complications for lateral wall resection?

Recurrence of disease Wound breakdown Wound infection

How do the aims, indications and contraindications of vertical ear canal ablation differ from lateral wall resection?

Also specifically indicated for excision of tumour on medial wall of vertical canal

What are the complications of a vertical ear canal ablation?

Hair around new stoma | Stenosis

What are the aims of a TECALBO?

Complete removal of all external ear tissue except pinna and removal of infected tissue within the middle ear

What are the indications of a TECALBO?

``` Chronic endstage otitis externa with obstruction of horizontal and vertical canals Persistent otitis following LWR/VCA Otitis externa and non-responsive OM Neoplasia of the horizontal canal Para-aural abscesses Severe ear canal trauma ```

What are the contraindications for a TECALBO?

Ear disease which can be effectively treated medically with or without a LWR/VCA Neoplasia that has extended outside the ear canal and middle ear

What are the complications of a TECALBO?

Conductive deafness rarely a major problem Facial nerve paresis/paralysis Haemorrhage Vestibular disease Infection and wound breakdown Fistula/sinus formation Avascular necrosis of the skin of the pinna

What is the anatomy of the middle ear?

``` Tympanic membrane, tympanic bulla, eustachian tube Auditory Ossicles (malleus, incus, stapes) ```

What are the structures of the inner ear?

Cochlea | Vestibulum, semicircular canals, utricle, saccule

What are the important differences between cat and dog middle ear anatomy?

Feline tympanic bulla is divided into two compartments Sympathetic nerves which distribute through the middle ear are more exposed/sensitive to iatrogenic trauma in cat than the dogs

What clinical signs result from damage to sympathetic nerves that run through middle ear?

Constriction of pupil Drooping of eyelid Sinking of eyelid

What are the treatment options for OM?

Medical management TECALBO Vental bulla osteotomy

What are the aims of a ventral bulla osteotomy?

Access to the middle ear for diagnostic and theraputic procedures

What are the indications for a ventral bulla osteotomy?

Aural polyps Middle ear neoplasia Primary otitis media

What are the contraindications of a ventral bulla osteotomy?

Otitis media with severe external ear disease

What are the complications of a ventral bulla osteotomy?

``` Recurrence of disease Horners syndrome especially in cats Hypoglossal nerve damage Vestibular syndrome Infection and wound breakdown Facial nerve paralysis ```