99. Nasal Cavity

Question 1

three nasal cartilages and dorsal and lateral support to the nose

Answer 1

1. dorsolateral nasal cartilage (ala nasi)2. ventrolateral nasal cartilage3. accessory nasal cartilagedorsal nasal ligament (connects cartilage to nasal bone)paired lateral nasal ligaments

Question 2

names of the air passages within the nasal cavity

Answer 2

MEATUSES (airways)dorsal, middle, ventral and commonvs. conchae (turbinates)–dorsal, middle, ventral and ethmoidal

Question 3

three paranasal sinuses

Answer 3

1. maxillary recess2. sphenoid sinus3. front sinus

Question 4

what is the choanae

Answer 4

rostral part of the nasaopharyngeal meatus (airway) and the caudal border of the nasal cavity

Question 5

borders of the nasopharynx

Answer 5

caudal to the nasal cavitydorsal–vomer boneventral–hard/soft palatelateral–palatine boneauditory tube enters the caudal nasopharynx (near pterygoid bone)

Question 6

functions of the nose

Answer 6

1. olfaction (caudally)2. moisture and heat exchange (rostrally/thru rich vascular supply)

Question 7

diagnostic approach to nasal disease

Answer 7

1. PE2. assess airflow3. oral exam and nasopharyngeal exam (use GA, digital palpation and visualization)4. Endoscopy (rhinoscopy/nasopharyngoscopy)5. intra-oral DV, open mouth VD, rostrocaudal frontal sinus radiographs6. advanced imaging (CT–esp of post radiation expected/MRI)

Question 8

ddx for dogs and cats with nasal disease

Answer 8

1. neoplasia (Adca, SCC, lymphoma)2. inflammatory (polyp)3. infectious (fungal, viral,bacT, nasal mite)4. FB5. dental disease with nasal extension6. idiopathic rhinosinuitis7. congenital abN (choanal atresia, ciliary dyskinesis)8. nasopharyngeal stenosis

Question 9

signs consistent with neoplasia on advanced imaging of the nose in dogs

Answer 9

BONE LYSIS/regional destructioncontrast enhancement of massseptal or cribiform destruction fungal masses may be cavitary with destruction present and inflammatory masses do not have destruction of bone and may not contrast enhancethese findings are debated in cats

Question 10

percent of cats with inflammatory disease of the nose with concurrent bulla effusion/thickening in the absence of otitis externa

Answer 10

30%

Question 11

T/Fseptal deviation and sinus asymmetry is normal in cats

Answer 11

true

Question 12

samples to submit for diagnosis of naso/nasopharyngeal disease

Answer 12

FNAcytology brushflushswabimprint (greater sensitivity than brush cytology)histopathculture (secondary bacT infxn common)PCR for opportunistic bugs (Mycoplasma and Bartonella))Ag serology (cryptococcus–cats)–HIGH SN/SP

Question 13

percent of masses found on retroflex nasopharyngoscopy that would have been missed on routine rhinoscopy

Answer 13

30%

Question 14

most common surgically addressed disease of the nasal planum

Answer 14

SCC (may transform from actinic dermatitis)–sunlight–papillomavirus–locally invasive–older white catsneoplasia is more common in cats> dogs in this regionother tumors possible

Question 15

survival time of surgically resected nasal SCC

Answer 15

surgery alone 4 monthsradiation alone 6 monthslocal recurrence is commonadjunct therapies may be required (cryotx, radiation, photodynamic tx, plesiotherapym intralesional chemo)

Question 16

stenotic nares pathophysiology

Answer 16

obstruction from axially oriented dorsolateral cartilages AND potentially abN conchae development (extending rostrally or cranially with abN branching) and presence of nasopharyngeal turbinates contribute to upper airway obstruction (BCAS)substantial NEG pressure needed to overcome obstruction leads to tissue edema, laryngeal and tracheal collapse in varying degrees

Question 17

breed associated with nasopharyngeal turbinates

Answer 17

82% pugs

Question 18

most common tumor type in dogs vs cats of the nasal caity

Answer 18

dogs–adenocarcinomacats–LSA

Question 19

T/Fcytoreductive surgery has been shown to improve survival in dogs with intranasal neoplasia

Answer 19

FALSEcytoreductive surgery has NOT shown to improve survival in dogs with intranasal neoplasia—offer radiation therapy for adenocarcinoma of nasal cavity MST 8-19 months–one study showed nasal extenteration following radiation sign improved survival but high complications because of previous radiation field

Question 20

feline upper respiratory tract infection complex

Answer 20

herpesviruscalicivirusChlamydophilaMycoplasmaBordetellaself limiting, support, may lead to chronic idiopathic rhinitis

Question 21

most common fungal pathogen of the nose in dogs

Answer 21

–aspergillus fumigatus(others: blastomycosis, pythium insidiosum)–young large breed dogs–destructive rhinitistx: trephination of sinus with infusion clotrimazole or enilconazole (highly invasive)ORballoon catheters into nasal cavity and occlusion of nasopharnyx and infusion of clotrimazole or enilconazole90% treated with multiple (up to 4) doses

Question 22

most common fungal pathogen of the nose in cats

Answer 22

–cryptococcus neoforms

Question 23

nasal mite

Answer 23

pneumonyssoides caninum

Question 24

nasopharyngeal polyps

Answer 24

–inflammatory benign condition—younger cats–arises from mucosa of the auditory tube, middle ear, or nasopharynx–55% bulla changes on CT

Question 25

treatment for nasopharyngeal polyps

Answer 25

–traction-avulsion +/- VBO: up to 50% recurrence with traction alone–VBOhorners and vestibular signs can be expected post op

Question 26

choanal atresia

Answer 26

congenital abN in which membrane fails to resorb and there is a lack of communication btwn the nose and the nasopharynxcomplete or partial (unilateral)osseous or membranoustx: balloon dilatation or open excision with choanal reconstruction

Question 27

nasopharyngeal stenosis

Answer 27

congenital (rare thickening of palatopharyngeal muscles in Dachshunds) most often acquiredtx:1. surgery resect stenosis: webbing and restenosis occur(need good tissue apposition)2. multiple balloon dilation–endoscopic guided 3. stent (BEMS) placement with endoscopy or fluoroscopy any of these procedures +/- intralesional triamcinolone or mitomycin C

Question 28

surgical techniques for stenotic nares

Answer 28

1. vertical wedge resection2. horizontal wedge resection3. Traders technique4. punch biopsy technique5. lateral wedge resection6. alapexy(scalpel, CO2 laser–3-5W continuous waveform with fine tip, electrosurgical techniques)

Question 29

blood supply to the nasal cavity

Answer 29

maxillary artery—major palatine and infraorbital arteryonce infraorbital artery leaves infraorbital foramen, branches into dorsal and lateral nasal arteries

Question 30

treatment for aberrant conchae

Answer 30

laser assisted turbinectomydiode laserused to ablate conchae and increase the ventral nasal meatus (airway)reduces airway resistance by 50% in BC dogs

Question 31

why does bilateral carotid artery ligation need to be avoided in cats

Answer 31

tolerated in dogs NOT catscats have a much less robust cerebral blood supply and LACK of internal carotid artery increases brain ischemic damage if external carotid is ligated

Question 32

4 approaches to the nasal cavity

Answer 32

1. dorsal (most common)2. ventral (ventral access to turbinates and cavity)3. lateral (unilateral exploration)4. alveolar mucosal (rostral cavity access)

Question 33

post op considerations following surgery of a nasal cavity`

Answer 33

1. pain (less with ventral approach)2. hemorrhage (pack with gauze +/- petroleum, remove day 1 post op)3. SQ emphysema (dorsal approach–avoid with providing a blow hole caudally or gauze stent on top incision)4. reduce risk of aspiration by elevating head5. avoid entrance of the cranial vault to avoid pneumocephalicus and/or septic meningoencephalitis6. chronic nasal serous discharge with removal of turbinates

Question 34

closure of the soft palate

Answer 34

THREE layersnasopharyngealmuscularoropharngeal

Question 35

sinusotomy

Answer 35

1. trephine2. longitudinal skin incision3. transverse skin incisiontrephine, burr, sagittal saw