Flashcards in Ear surgery Deck (57):
What attaches ear cartilage to the head medially?
What artery supplies the pinna?
great auricular artery
What is the tragus?
a small, pointed eminence of the external ear
Define aural haematoma
collection of blood within the cartilage plate of ear from damage to branches of great auricular artery. cause unknown, probably trauma to pinna, usually produces a swelling on concave surface of ear
CAuses - aural haematoma
- Predisposing factors = headshaking, ear scratching
- Underlying causes = aural inflammation, parasites, allergy, FB
Outline possible progression of aural haematoma
Haematoma --> seroma --> fibrosis --> contraction deformity
Tx aims - aural haematoma
- address underlying source of irritation
- evacuate haematoma
- prevent recurrence
Conservative management - aural haematoma
- needle aspiration (+/- corticosteroid injection) = high recurrence rate
- pressure bandage, difficult to apply well
- continuous drainage through a canula, penrose or closed suction drain for 2-3 weeks
Surgical management - aural haematoma
- incise concave pinna (linear, ovoid, S or X shaped)
- evacuate haematoma
- appose cartilage with sutures (place vertically so parallel to major vessels, minimise tension. place through cartilage and one or both skin surfaces)
- don't suture incision (leave open for drainage)
- light bandage for several days
- remove sutures at 10-14 days.
What is amputation of the pinna called?
Indications - pinnectomy
- solar injury (white cats especially)
- cold injury (uncommon)
- permanent marking (ferals)
Outline method for pinnectomy
Try to excise with 1cm of normal margins if treating neoplasia, submit for histopath, close by primary apposition of skin edges over amputated cartilage.
What do you need to decide for external and middle ear disease?
1.) if or when surgical tx is necessary
2.) if it is what type of surgical procedure is appropriate
CS - middle ear disease
- head shake
- tilt/ rotate head (to affected side)
- self-trauma (aural haematoma)
CS - inner ear disease
- as for OM
- poss damage to vestibular and auditory structures and nn (problems with balance, coordination, circling, head tilt, nystagmus, hearing loss. CNS signs if infection extends into CNS).
Key features of an aural exam
- if ear disease is painful/ advanced perform under sedation/ GA
- suction of a blocked ear canal allows proper assessment
- how stenosed or disesed are the vertical and horizontal canals
- state of the TM
- mass visible?
Outline ear radiography
- requires GA
- 3 views (DV skull, open-mouth bullae, lateral oblique bullae)
- evidence of ear canal stenosis, calcifications?
- evidence of middle ear disease (normal bulla has thin walls and contains air)
- chest radiographs if neoplasia suspected
T/F: normal radiographs rule out middle ear disease
False - normal radiographs DON'T rule out middle ear disease
what are the 3 parts of the external ear canal?
- vertical (auricular cartilage)
- horizontal (annular cartilage)
- vertical and horizontal canals joined by annular ligament
What lines external ear canal?
strat. sq. epithelium (to tympanic bulla)
Where do the facial nerve exit?
stylomastoid formen (caudal to ear) and runs ventrolateral in close proximity to the base of the external ear canal/ middle ear cavity
CS - facial nn damage
- inability to blink
- lip droop (look for facial symmetry)
- dry eye (inadequate tears)
What sx may be useful in repeat otitis externa?
lateral wall resection
Tx - endstage otitis externa (usually with concurrent OM)
TECA = total ear canal ablation
LBO = lateral bulla osteotomy
Aim of lateral wall resection (LWR)
- increase drainage and ventilation of ext. ear canal
- decrease moisture, humidity and temp.
Indications - lateral wall resection
OE that hasn't responded OR has recurred despite appropriate medical management
Contra-indications - lateral wall resection
- chronic, endstage OE
- irreversible horizontal canal disease/ stenosis
Describe surgical technique for lateral wall resection
- clean ear - clip widely - lateral recumbency - sandbag under neck - make vertical parallel skin incision from tragic notches ventrally - connect skin incisions ventrally and reflect skin flap dorsally - stay close to lateral cartilage of ear canal - void parotid gland - incise cartilage of lateral ear canal in two parallel vertical cuts from annular ligament to intra- and pre-tragic notches - reflect cartilage ventrally and remove excess cartilage to form a 'baffle plate' hinged about annular ligament - suture cartilage to skin epithelium (interrupted) - always place a buster collar - remove sutures at 10- 14 days
Complications - lateral wall resection
- disease recurrence
- wound breakdown
- wound infection
Vertical Ear Canal Ablation
Indications - VECA
as for LWR (OE that hasn't responded or has recurred despite appropriate medical management) AND is specifically indicated for tumour excision on medial wall of vertical canal
Sx technique - VECA
- cut around ext. auditory meatus - extend skin incision vertically and ventrally - blunt dissect around vertical canal - excise vertical canal 1-2cm above annular ligament - cut remaining vertical canal cranially and caudally to lever of annular ligament producing 2 baffle plates (ventral and dorsal) - suture as for LWR (suture cartilage to skin epithelium, interrupted sutures) - close any remaining skin with simple interrupted
Complications - VECA
- hair around new stoma
Total Ear Canal Ablation
Lateral Bulla Osteotomy
Aims TECA and LBO
complete removal of all external ear tissue except pinna and removal of infected tissue within middle ear (salvage procedure)
Indications - TECA and LBO
- chronic endstage OE with obstruction of horizontal and vertical canals
- persistent otitis following LWR/ VCA
- OE + non-responsive OM
- neoplasia of horizontal canal (ceruminous gland adenocarcinoma, SCC)
- para-aural abscess
- severe ear canal trauma
Contraindications - TECA and LBO
- ear disease which can be effectively tx medically with or without a LWR/VCA
- neoplasia that has extended outside the external ear canal and middle ear (e.g. to surrounding soft tissues or brain)
Sx technqiue - TECA
- cut around ext. auditory meatus - dissect around vertical and horizontal canals, stay v close to cartilage, avoid facial nerve - excise canal at level of tympanic bulla (ext. acoustic meatus) - remove residual canal cartilage and epithelium with rongeurs (LBO) - flush middle ear and carefully remove epithelium lining middle ear - close SC tissues and suture cartilage to skin with interrupted sutures
Complications - TECA
- conductive deafness (rare)
- facial nerve paresis/ paralysis (56% cats)
- horner's syndrome (42% cats)
- haemorrhage (retroglenoid vein or carotid artery ventral to bulla)
- vestibular disease
- infection and/or breakdown
- fistula/ sinus formation (usually poor sx)
- avascular necrosis of pinna skin (damage to greater auricular artery)
Name the 2 components of the inner ear
Vestibulum (semicircular canals, utricle, sccule) and cochlea
What is found in the tympanic bulla?
- (aka the middle ear).
- 1 compartment (dog)
- 2 compartments (cat) the malleus, incus and stapes are found here.
Sympathetic nerve which distribute through the middle ear are more exposed/ more sensitive to trauma in which species?
CS - Horner's syndrome (sympathetic nerve damage)
- myosis (little pupil)
- upper eyelid droops
- enopthalmia (posterior displacement of eyeball in orbit)
- loss of tone of orbital SMC
- 3rd eyelid protrusion
How may OM arise in dogs?
* extension through ear drum from external ear (up to 75% dogs with chronic OE have concurrent OM)
- rarely arises from haematogenous OR from nasopharynx via the eustachian tube
- KCCS may have primary dysfunction of eustachian tube leading to excess accumulation of mucus in middle ear and deafness
How may OM arise in cats?
- OM as a result of OE is compartively rare
- asceding viral infection from nasopharynx associated with episodes of URT disease often implicated in the development of polyps which originate from the lining of the tympanic bulla OR eustachian tube
- POLYPS may:
1. remain in middle ear and cause signs of OM
2. extend into nasopharynx causing resp distress, gagging and retching
3. extend across the ear drum and obstruct the external ear canal producing secondary OE
How may polyps be removed from feline ears?
- traction (nasopharyngeal rather than aural polyps do best. recurrence is a problem)
- Ventral Bulla Osteotomy (VBO) - much lower risk of recurrence but risks of sx are greater than with simple traction
surgical incision into eardrum, to relieve pressure or drain fluid
List tx options for OM
- medical (myringotomy, flushing, 3-6 wks ABs)
- TECA/ LBO
- Ventral Bulla Osteotomy
When is medical tx of OM indicated?
only works if only OM is present but is not often succesful
When is TECA/LBO indicated for tx of OM?
If OM is present WITH significant external ear disease, then TECA/ LBO is most practical approach
When is Ventral Bulla Osteotomy indicated for tx of OM
if OM is present WITHOUT severe external ear disease (e.g. aural polyps in cats)
Aim - ventral bulla osteotomy
access to middle ear (diagnostic and/or therapeutic)
Indications - ventral bulla osteotomy
* aural polyps *
- middle ear neoplasia (rare)
- primary otitis media 9rare)
Contraindications - ventral bulla osteotomy
OM WITH severe external ear disease (however instead do TECA/ LBO)
Outline sx method for Ventral Bulla Osteotomy
- clip wide on ventral neck - dorsal recumbency - sandbag under neck - palpate bulla just caudal to mandible - paramedian incision centred over bulla - deepen incision by blunt disesection (avoid hypoglossal nn) - use a steinman pin/ burr/ rongeurs to make a hole in the ventral bulla - in cats be sure to enter both compartments - remove diseased tissue - submit for histopath - flush copiously - close SC tissue with absorbable simple continuous suture - close skin with simple interrupted MFN sutures (multifilament?)