Stenose der Apertura piriformis

Newborn with

inability to pass nasogastric tube through the noseAxial CT without contrast of the face shows narrowing of the pyriform apertures bilaterally.The diagnosis was pyriform aperture stenosis.

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Congenital

nasal pyriform aperture stenosis, single central maxillary incisor and ectopic posterior pituitary gland. Axial CT scan at the level of the maxillary bone. (a)Normal pattern with a wide bilateral nasal pyriform aperture and (b)Congenital nasal pyriform aperture stenosis (arrow).

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Pyriform aperture stenosis refers to narrowing of the pyriform aperture and results from early fusion and hypertrophy of the medial nasal processes.

Epidemiology

Pyriform aperture stenosis is a rare cause of airway obstruction, and its prevalence is unknown.

Pathology

Associations

alobar and semilobar forms of holoprosencephaly
facial hemangiomas
clinodactyly
pituitary dysfunction
central megaincisor (in 75% of cases)

Radiographic features

CT

HRCT is the imaging modality of choice. It is performed in planes angled along the hard palate with a section thickness of 1-1.5 mm and should include the maxillary spines.

Imaging features of pyriform aperture stenosis include:

inward bowing and thickening of nasal processes of maxilla
narrowing of the pyriform aperture measuring less than 8 mm (normal is not <11 mm)

MRI / ultrasonography

Associated intracranial anomalies can be excluded in infants with MR imaging or ultrasonography.

Treatment and prognosis

Treatment of mild cases of pyriform aperture stenosis includes administration of decongestants, which allows time for normal nasal growth. Severe cases may require surgical reconstruction with stent placement, sublabial resection of the anteromedial maxilla, or reconstruction of the anterior nasal passages.