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683.e2 Nasopharyngeal Stenosis

Nasopharyngeal Stenosis Client Education
Sheet
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○ Sneezing
BASIC INFORMATION
○ Gagging/repetitive swallowing DIAGNOSIS
Definition ○ Intermittent respiratory distress, especially Diagnostic Overview
This uncommon disorder consists of pathologic cats because they are reluctant to open- The clinical signs are usually chronic, non-
narrowing or obliteration of the communication mouth breathe. Increased inspiratory and specific and typical for upper respiratory tract
between the nasopharynx and oropharynx. The expiratory effort is consistent with a fixed disease. Findings may be variably progressive,
rostral nasopharynx is commonly involved in airway obstruction. depending on the underlying cause of disease.
dogs (87%), but the caudal nasopharynx is more ■ Signs resolve with open-mouth Nasopharyngeal stenosis can sometimes be
commonly involved in cats (71%). breathing. confirmed through direct visualization of
• Worsening of the respiratory signs during the nasopharynx (i.e., retroflexed rhinoscopic
Epidemiology sleeping, eating, or swallowing view), although cross-sectional imaging may be
SPECIES, AGE, SEX • Poor response to empirical therapy required to determine the tissues involved, as
Nasopharyngeal stenosis can occur in cats and • History of chronic upper respiratory well as the length and diameter of the lesion.
dogs of any age or sex. A study of 46 patients infections, surgery, facial trauma, or recent
reported a median age of 2.4 years (range, anesthesia Differential Diagnosis
0.25-16.5 years). • Nasopharyngeal polyps
PHYSICAL EXAM FINDINGS • Chronic rhinitis or sinusitis
GENETICS, BREED PREDISPOSITION • Nasal discharge: serous-mucoid, may be • Foreign body
Smooth-haired dachshunds have been described unilateral or bilateral; may become muco- • Intranasal or nasopharyngeal neoplasia
with anomalous development of pharyngeal purulent with secondary infection • Mycotic rhinitis (granuloma)
musculature, contributing to caudal nasopha- • Nasal stertor
ryngeal stenosis. A study of 46 patients reported • Decreased nasal airflow Initial Database
congenital webbing in 6.5% of cases. • Intermittent open-mouth breathing CBC, serum biochemical profile, urinalysis:
• Signs consistent with inflammatory rhinitis usually unremarkable
RISK FACTORS (p. 890)
• Secondary to recurrent/chronic rhinitis in • Repetitive swallowing and cough may be Advanced or Confirmatory Testing
dogs and cats (17%) observed in patients with EERD. • Diagnostic imaging
• Gastric reflux into the nasopharynx (17%) and ○ Skull radiographs may be normal or show
chronic upper respiratory infections (9%) are Etiology and Pathophysiology evidence of previous trauma or opacifica-
most common in dogs and cats, respectively. • In cats, this condition is thought to result tion of turbinate structures secondary to
• Stenosis after anesthetic events and naso- from scar formation across the rostral accumulation of nasal secretions or a mass
pharyngeal surgery/trauma (4%) are also nasopharynx secondary to mucosal ulcer- in the nasopharynx. Rostrocaudal views
reported. ation from chronic rhinitis and/or sinus- may provide evidence for chronic otitis
• The cause of stenosis remains unknown in itis. The disease is usually associated with media.
up to 45% of cases. recurrent upper respiratory tract infections ○ CT can document the presence of a
or allergic disease. Scar formation leads stenotic lesion or mass in the nasopharynx.
ASSOCIATED DISORDERS to complete or partial obstruction of the Thin slices are recommended to allow
• Chronic rhinitis and sinusitis rostral nasopharynx, resulting in the accu- measurement of the length/diameter of
• Extraesophageal reflux disease (EERD) mulation of nasal secretions in the nasal the stenotic lesion, as well as diameter
• Chronic otitis media cavity and consequent nasal stertor and of the nasopharynx rostral and caudal to
• Palate defects discharge. the lesion to facilitate treatment planning.
• Nasopharyngeal injury from surgery or Nasal secretions rostral to the stenosis may
Clinical Presentation contact with gastric contents or other caustic falsely increase stenosis length.
DISEASE FORMS/SUBTYPES material can presumably provoke inflamma- • Other diagnostic procedures
• Although congenital stenosis of the internal tion and scar tissue formation. This is most ○ Inability to pass a small catheter (3.5 Fr)
nasal meatus has been described in the common in dogs. gently through the ventral nasal meatus
literature, most cases are acquired. • Chronic inflammation from nasopharyngeal into the pharynx
• Stenosis is described as patent (47% of foreign bodies in dogs has been anecdotally ○ Visualization of the membrane with a
dogs, 90% of cats) or imperforate (53% associated with the disorder. retroflexed bronchoscope or a dental mirror
of dogs, 10% of cats), referring to a hole • Abnormal development of the muscles can be performed alone or in combination
in the obstructive membrane or complete of the soft palate and pharynx, causing with catheter placement as above.
obstruction, respectively. stenosis of the caudal nasopharynx, ■ Retroflex rhinoscopy (p. 1159) may be
• Stenosis is most commonly soft tissue has been described in smooth-haired used in combination with fluoroscopy
(pharyngeal musculature, banding/webbing) dachshunds. and antegrade contrast nasopharyngos-
but may also occur secondary to nasal masses • Changes in bony architecture (congenital or copy to determine length of stenosis.
or changes in bony architecture, which may secondary) may also cause stenosis. ○ Histopathology or cytology: evaluate
change or limit treatment options. • Nasopharyngeal tumors can cause stenosis. comorbid conditions (e.g., masses, rhinitis)
• Choanal atresia with secondary rostral
HISTORY, CHIEF COMPLAINT nasopharyngeal stenosis in a 20-month-old TREATMENT
Some or all of the following may be present: Shih Tzu dog has been reported.
• Upper respiratory tract disease • A cat developing nasopharyngeal stenosis Treatment Overview
○ Nasal discharge after surgical correction of bilateral bony The primary aim of therapy is restoration of
○ Nasal stertor choanal atresia has been reported. nasopharyngeal patency.

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