Diseases of the Equine Nasal Passages & Paranasal Sinuses Flashcards by Renee DeAngelis

What are the most common causes of unilateral epistaxis?

dry mucous membranes (cold weather)
exertion
ethmoid hematoma
nasal polyps
guttural pouch mycosis
neoplasia

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What are the most common causes of bilateral epistaxis?

EIPH in racehorses and barrel horses
head trauma
clotting disorders
severe pleuropneumonia

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What are the sources of motor and sensory innervation to the nostrils? What keeps them from collapsing?

MOTOR = facial nerve
SENSORY = trigeminal nerve

cartilaginous support over nasoincisive notch

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What is being pointed to in this picture?

nasal diverticulum (false nostril)

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What are external nares atheromas (epidermal inclusion cysts)? How are they diagnosed?

cyst in the false nostril of unknown etiology

unilateral spherical nodule within the nasal diverticulum noted on PE
FNA and cytology

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How are external nares atheromas treated? What is prognosis like?

surgical (cosmetic) removal or drainage into the nasal cavity and destruction of the cyst lining with a roaring burr

excellent —> no recurrence reported

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External nares atheroma (epidermal inclusion cyst) removal:

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What are some causes of general nasal passage problems?

trauma
inflammation
infection: abscess, granuloma
neoplasia
congenital: Wry Nose = crooked, deviated nasal septum (can affect nursing and ability to become an athelete)

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What are common clinical signs associated with nasal septum problems?

respiratory noise
decreased outflow
nasal discharge
facial deformity

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What is the most helpful view when radiographically diagnosing nasal septum abnormalities? What other modalities can be used?

DV —> able to view thickening, malformation, and septal deviation

CT
endoscopy (not as helpful)

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How are nasal septum problems most commonly treated? What must occur?

resection of the septum

leave rostral section intact to avoid collapse

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What is a nasal polyp? What are the most common clinical signs? How is it treated?

pedunculated growths from the mucosal of the nasal cavity or septum

inspiratory dyspnea
nasal discharge
odor

surgical excision

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What is a progressive ethmoid hematoma?

usually unilateral, non-neoplastic mass that originated from the submucosa of the ethmoid labyrinth or paranasal sinuses that is able to slowly expand down the nasal passages and/or into the sinuses

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What is the most common clinical sign seen with ethmoidal hematomas? What else is seen?

unilateral, mild, intermittent, epistaxis of serosanguinous discharge

respiratory noise
dyspnea
head shaking
halitosis
facial deformity

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What definitive diagnostic is used for ethmoidal hematomas?

endoscopy —> greenish-yellow to purplish-red mass with a smooth surface +/- fungal plaques (can be biopsied!)

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Ethmoidal hematoma, radiograph:

ST opacity

What surgical treatment is performed for ethmoidal hematomas?

excision - mass removal and destruction of origin, commonly by frontonasal bone flap

What are 2 options for transendoscopic treatments of ethmoidal hematomas?

laser
intra-lesional 4% formaldehyde injection repeated 3-4 week intervals

What sinuses are in the anatomical sites in this picture?

BLUE = conchofrontal

YELLOW = rostral maxillary

ORANGE = caudal maxillary

How are the compartments of the paranasal sinuses connected? Where do they drain?

all communicate directly or indirectly

nasomaxillary opening

What sinuses have tooth roots within them?

rostral maxillary - 8, 9

caudal maxillary - 10, 11

What are the most common causes of primary and secondary sinusitis? What clinical sign is most commonly associated?

PRIMARY = URT infection, most commonly Strep sp

SECONDARY = tooth root abscess, trauma (facial fracture), neoplasia

unilateral purulent or serous nasal discharge - odorous = tooth root abscess

What are some additional signs of sinusitis?

epiphora
conjunctivitis
enlarged submandibular LNs
respiratory noise
facial deformity (rare, more common with cysts)

What are the most common causes of unilateral and bilateral nasal discharge?

UNILATERAL = sinuses, nasal cavity

BILATERAL = guttural pouches, nasopharynx, lungs, both paranasal sinuses (primary sinusitis)

How are radiographs, endoscopy, and sinocentesis used to diagnose sinusitus?

opacity and fluid lines within the sinus purulent discharge at nasomaxillary opening, unable to see into sinus aspirate purulent material from sinus

What 3 modes of diagnostics are used to evaluate refractory cases of sinusitis?

1. sinocentesis - cytology, culture, lavage 2. sinoscopy - visualize with minimal invasion 3. CT - best for complicated cases

What needs to be considered when performing sinus trephination?

AGE - younger horses have longer tooth roots within the maxillary sinuses

How is primary and secondary sinusitis treated?

PRIMARY - copious lavage with 5-10 L of sterile, warm saline, systemic antibiotics based on C&S SECONDARY - same as above, correct underlying causes

What are the 4 most common causes of treatment failure incases of sinusitis?

1. inspissated pus common in the ventral conchal sinus too hard and unable to be flushed 2. failure to treat primary problem 3. fungal infection 4. neoplasia

How are refractory cases of sinusitis treated?

sinusotomy with sinus flap giving direct access to sinus with removal of exudate to improve sinonasal drainage

What are sinus cysts? What is the most common clinical sign? What else is seen?

fluid-filled structure lined by epithlium of unknown etiology (possibly congenital) facial deformation - unilateral mucoserous nasal discharge with NO ODOR - reduced airflow on affected side

What are the best diagnostics for sinus cysts? How are they treated? What is prognosis like?

- radiographs** - space-occupying mass WITHOUT bone destruction - CT sinusotomy to remove (must remove lining to avoid recurrence!) good if fully removed

What is the most common sinus neoplasia? How does it act? What are the most common clincial signs?

SCC ---> malignant and invasive - nasal discharge - facial deformity - loose teeth - epiphora

How are sinus neoplasias diagnosed? Treated?

- diagnostic imaging - soft tissue in sinus with osseous changes - aspirate fluid for cytology - biopsy radiation, high likelihood of recurrence and poor prognosis commonly leads to euthanasia

What is the most common approach to sinusotomies?

frontonasal or maxillary bone flaps ---> 3-sided and hinged on fourth side

How is the patient situated for a sinusotomy? How is the bone flap created?

standing sedation or GA - mallet and osteotome (angle for a beveled edge so flap doesn't fall in) - oscillating saw

Sinusotomy:

What are 3 important strategies for managing patients following sinusotomies?

1. make a large opening into the nasal cavity to facilitate drainage 2. post-op lavage - plan to place a foley catheter 3. pack the sinus to control hemorrhage and remove within 48-72 hours

What are the 3 most common complications associated with sinusotomies?

1. hemorrhage - especially with ethmoid hematomas 2. recurrence 3. failure to resolve clinical signs