99. Nasal Cavity Flashcards
three nasal cartilages and dorsal and lateral support to the nose
- dorsolateral nasal cartilage (ala nasi)2. ventrolateral nasal cartilage3. accessory nasal cartilagedorsal nasal ligament (connects cartilage to nasal bone)paired lateral nasal ligaments
names of the air passages within the nasal cavity
MEATUSES (airways)dorsal, middle, ventral and commonvs. conchae (turbinates)–dorsal, middle, ventral and ethmoidal
three paranasal sinuses
- maxillary recess2. sphenoid sinus3. front sinus
what is the choanae
rostral part of the nasaopharyngeal meatus (airway) and the caudal border of the nasal cavity
borders of the nasopharynx
caudal to the nasal cavitydorsal–vomer boneventral–hard/soft palatelateral–palatine boneauditory tube enters the caudal nasopharynx (near pterygoid bone)
functions of the nose
- olfaction (caudally)2. moisture and heat exchange (rostrally/thru rich vascular supply)
diagnostic approach to nasal disease
- 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)
ddx for dogs and cats with nasal disease
- 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
signs consistent with neoplasia on advanced imaging of the nose in dogs
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
percent of cats with inflammatory disease of the nose with concurrent bulla effusion/thickening in the absence of otitis externa
30%
T/Fseptal deviation and sinus asymmetry is normal in cats
true
samples to submit for diagnosis of naso/nasopharyngeal disease
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
percent of masses found on retroflex nasopharyngoscopy that would have been missed on routine rhinoscopy
30%
most common surgically addressed disease of the nasal planum
SCC (may transform from actinic dermatitis)–sunlight–papillomavirus–locally invasive–older white catsneoplasia is more common in cats> dogs in this regionother tumors possible
survival time of surgically resected nasal SCC
surgery alone 4 monthsradiation alone 6 monthslocal recurrence is commonadjunct therapies may be required (cryotx, radiation, photodynamic tx, plesiotherapym intralesional chemo)
stenotic nares pathophysiology
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
breed associated with nasopharyngeal turbinates
82% pugs
most common tumor type in dogs vs cats of the nasal caity
dogs–adenocarcinomacats–LSA
T/Fcytoreductive surgery has been shown to improve survival in dogs with intranasal neoplasia
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
feline upper respiratory tract infection complex
herpesviruscalicivirusChlamydophilaMycoplasmaBordetellaself limiting, support, may lead to chronic idiopathic rhinitis
most common fungal pathogen of the nose in dogs
–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
most common fungal pathogen of the nose in cats
–cryptococcus neoforms
nasal mite
pneumonyssoides caninum
nasopharyngeal polyps
–inflammatory benign condition—younger cats–arises from mucosa of the auditory tube, middle ear, or nasopharynx–55% bulla changes on CT
treatment for nasopharyngeal polyps
–traction-avulsion +/- VBO: up to 50% recurrence with traction alone–VBOhorners and vestibular signs can be expected post op
choanal atresia
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
nasopharyngeal stenosis
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
surgical techniques for stenotic nares
- 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)
blood supply to the nasal cavity
maxillary artery—major palatine and infraorbital arteryonce infraorbital artery leaves infraorbital foramen, branches into dorsal and lateral nasal arteries
treatment for aberrant conchae
laser assisted turbinectomydiode laserused to ablate conchae and increase the ventral nasal meatus (airway)reduces airway resistance by 50% in BC dogs
why does bilateral carotid artery ligation need to be avoided in cats
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
4 approaches to the nasal cavity
- dorsal (most common)2. ventral (ventral access to turbinates and cavity)3. lateral (unilateral exploration)4. alveolar mucosal (rostral cavity access)
post op considerations following surgery of a nasal cavity`
- 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
closure of the soft palate
THREE layersnasopharyngealmuscularoropharngeal
sinusotomy
- trephine2. longitudinal skin incision3. transverse skin incisiontrephine, burr, sagittal saw
