Ch 122 Pinna and external ear Flashcards

Question

What may complicate a TECA-LBO in brachycephalic breeds?

Answer 1

In many, the bulla sits medial to the mandible | option for these dogs is to perform a ventral bulla osteotomy

Answer 2

- To avoid ischemic necrosis of the pinna, the medial incision should not extend too far up the pinna - working deep to the perichondrium - facial nerve is located caudoventral to the canal at the level of the terminal horizontal canal - “keyhole” osteotomy to allow for curettage of the bulla floor, a common location for epithelium to be retained. - removal of tympanic membrane and auditory ossicles usually leads to complete and irreversible hearing loss - facial nerve is established and artificial tears or ophthalmic ointment applied as needed.

Answer 3

* Preserve medial pinna cartilage and a portion of the distal (dorsal) vertical ear canal * 46% mild to moderate skin infection in preserved canal

Answer 4

Caudal part of pinna folded forward and sutured to rostral aspect Ventrally based, single-pedical advancement flap

Answer 5

- Samples are preferably obtained after lavage - duration of antimicrobial administration after ear canal ablation in dogs ranges from 7 to 30 days (no strong evidence peri-op abs make a difference) - Antibiotic treatment is rarely effective for resolving recurrent middle ear infections that develop after TECA - recurrent otitis media, fistula development, and para-aural abscessation are predominantly linked to incomplete removal of annular cartilage, inadequate debridement and removal of middle ear epithelium, and presence of residual debris

Answer 6

drains - study found no difference in the incidence of immediate or long-term complications in dogs with wounds closed primarily and those that had indwelling passive Penrose drain placemen analgesia - Use of opioids alone is often insufficient, with many patients developing breakthrough pain - continuous local infusion of 2% lidocaine - 40% of the dogs undergoing local infusion of lidocaine or sterile saline had wound complications

Answer 7

- severe hemorrhage 5.5-15.6% (requiring a blood transfusion) post-op: overall 21-53%; * SSI, drainage tracts, abscess 2-50%; abscess can develop 5-10mths later * Horner’s 3.3% * facial n injury 13-36%, up to 15% permanent * vestibular dz 1-8%, * hypoglossal n injury 3-8% * pinna necrosis * poor cosmesis * deafness cats: * Horner’s 27-70%, * facial n injury: 12-56% (up to 28% permanent)

Answer 8

Results from damage to postganglionic sympathetic fibres running through middle ear Cats: - 27-42% post-op (70%) - 14-27% permanent less common in dogs | enophthalmos, elevation of the third eyelid, miosis, and ptosis

Answer 9

Dogs: - 13-39% post-op - 4-13% permanent Cats: - 12-56% post-op - 28% permanent

Answer 10

3-14%, most commonly from retroglenoid vein

Answer 11

* TECA-LBO - improvement in 57-92% * Cholestestoma - 10/19 recurrence or persistence after TECA-LBO

Answer 12

* Epidermoid cyst located within the middle ear. Composed of keratin debris, surrounded by keratinising stratified squamous epithelium, inflammatory cells and more keratin debris * Presence of preop neuro signs correlated with post-op recurrence

Answer 13

Histological grade - Grade 1 and 2 - MST not reached, recurrence 1/20 - Grade 3: MST 10 months, recurrence 7/8

Answer 14

Involvement of bulla and ear canal associated with shorter survival - MST 5.3m vs 30m if confined to horizontal or vertical ear canal

Answer 15

Neuro signs Histo diagnosis of SCC or anaplastic carcinoma (as apposed to ceruminous adenocarcinoma)

Answer 16

A total of 13 feline cadaver heads osseus structures of the middle ear were readily visualized with a 1.9 mm scope endoscope does not appear to increase the success rate of entry into the hypotympanum during feline TECALBO

Answer 17

Recurrence was identified in 1/14 (7%) ceruminous gland adenomas and 1/12 (8%) ceruminous gland adenocarcinomas. Conclusions and Clinical Importance: Video-otoscopic aided biopsy and CO2 laser ablation of ceruminous gland tumors in dogs and cats is a viable treatment option with low recurrence and complication rates with CO2 laser ablation.

Answer 18

Cross-sectional retrospective study. 242 dogs TECA-LBOs extreme brachycephalic 81, other breeds 225 a younger age presented more frequently with facial nerve paresis, vestibular syndrome , and Horner’s syndrome jaw pain, para-aural abscesses , otitis interna, and brainstem changes were more common CT anatomical differences: thickened bulla wall, abnormal location, narrow external bony meatus diameter, proximity of neurovascular structures intraoperative complication: EBBs (9/81, 11.1%) and OBs (12/225, 5.3%) did not reach statistical significance subjectively more technically challenging in EBB facial 29% iatrogenic haemorrhage 5% no difference in perioperative complication rates between unilateral, single-session bilateral, and staged bilateral TECA-LBO

Answer 19

computed tomographic dimensions of the nasopharynx on middle ear effusion Middle ear effusion (56.7%) French bulldogs and (16.7%) pugs French bulldogs with BOAS seem predisposed to middle ear effusion The ventral wall of the bulla is significantly thicker in French bulldogs Previously reported as incidental finding (prevalence of up to 41%)

Answer 20

Experimental study. Otoscopic evaluation of epithelial remnants after TECABO use of 1.9mm rigid endoscope - epithelial remnants in at least 1/5 areas after all TECA-BO - most common rostrally (35%), least common medially - caudal, rostral, dorsal > ventral, medial Intraoperative endoscopy >improve removal of epithelium after initial TECA-LBO or revision surgeries allow better visualization and curettage in safe areas away from delicate structures such as the ossicles and internal ear structures. aggressive dissection of the rostromedial > iatrogenic injury to the round and oval windows , inner ear and internal carotid artery (medial to the bulla wall)

Answer 21

diagnosed with SCC of the ear canal, middle or inner ear Twenty-five cats were identified. Eleven cats were treated with surgery, eight with medical management, two with coarse fractionated radiation therapy The median survival time of cats treated with surgery was 168 days vs 85 days (P = 0.28) for those treated palliatively locally aggressive tumor that carries an overall poor prognosis.

Answer 22

Effect of empirical versus definitive antimicrobial selection on postoperative complications 95/111 (85.5%) positive on intraoperative culture during TECA-LBO - Staphylococcus spp most common - revision due to infection in 13/120 (10.8%) - pain on opening the mouth → 7.4x of requiring revision - 10.3x higher risk of revision with positive culture without antimicrobials - ~50% facial paralysis, 3.3% permanent Use of a surgical drain, suture type, and intralesional analgesia was not significantly associated with any of the outcome variables. duration and choice of systemic antimicrobial no effect, antimicrobials postoperatively could play a role in the successful long-term outcome. Need prospective RTC to determine the true effects of antimicrobial therapy on compli cation rates and outcomes

Answer 23

Hettlich 2005 – evacuation and lavage of the tympanic cavity reduced bacterial isolates by 33% - bacteria remain after evacuation and lavage - pre-op and post-lavage culture isolates differed in 84% - 26% isolates susceptible to cefazolin – poor choice of peri-operative antibiotic - 53% dogs had at least 1 isolate resistant to empirically selected antibiotic

Ch 122 Pinna and external ear Flashcards

(47 cards)