PIRIFORM APERTURE STENOSIS

Piriform Aperture Stenosis, or PAS, is a rare congenital condition causing significant nasal obstruction in neonates. This obstruction arises from bony overgrowth of the nasal process of the maxilla, narrowing the piriform aperture, which is the narrowest part of the nasal airway. In neonates, even a minor reduction in this space can cause serious breathing difficulties. [Display first image of CT scan] Diagnosis is often suspected when there is an inability to pass a nasogastric tube through the nasal vestibule. A CT scan, as shown here, is critical to confirm PAS, revealing an aperture width of less than 11mm at the level of the inferior turbinate in term neonates. Symptoms of PAS often mimic those of bilateral choanal atresia, including nasal obstruction and respiratory distress. Additionally, epiphora—or excessive tearing—may occur due to involvement of the nasolacrimal ducts. In some cases, associated abnormalities are present, including the presence of a single central incisor. [Display second image with mega incisor] This incisor is often accompanied by an absent upper frenulum and is sometimes linked to holoprosencephaly, a serious brain malformation where the forebrain fails to properly divide. It is crucial to conduct further MRI evaluation to assess for central nervous system defects, particularly affecting the hypothalamic-pituitary-thyroid axis. The treatment of PAS depends on the severity. In mild cases, conservative management with nasal steroid drops, decongestants, and saline irrigation is recommended for up to two weeks. However, in cases of severe obstruction, surgical intervention is necessary. This is often the case when the CT scan shows an aperture of less than 5mm. There are two primary surgical approaches: a transnasal approach or a sublabial approach. Both involve the removal of the bony overgrowth using a diamond burr, followed by careful reconstruction. [Display third image showing nasal stents] Postoperatively, nasal stents may be placed for up to four weeks, although recent studies suggest that stenting may not always be required. Common complications after surgery include nasal adhesions, septal perforations, and ulceration. These can be managed with proper postoperative care, including nasal irrigation and addressing any gastroesophageal reflux if present. In conclusion, while Piriform Aperture Stenosis is a rare but potentially serious condition, early diagnosis and treatment—whether conservative or surgical—can prevent long-term complications and improve neonatal respiratory function.