|Year : 2015 | Volume
| Issue : 3 | Page : 203-205
Congenital nasal pyriform aperture stenosis: A rare cause of respiratory distress in newborn
N Dinesh Kumar, A Arul Kumaran, S Balaji, R Anupriya
Department of Pediatrics, Sri Manakula Vinayagar Medical College and Hospital, Puducherry, India
|Date of Web Publication||2-Jul-2015|
N Dinesh Kumar
No 15, First Floor, 6th Cross, Bharathi Dasan Nagar, Mudaliyarpet, Puducherry - 605 004
Source of Support: None, Conflict of Interest: None
Congenital nasal pyriform aperture stenosis is a lethal cause of neonatal respiratory distress due to narrowing of the pyriform aperture anteriorly. It is the most narrow part of the nasal airway, any decrease in the cross-sectional area will increase the airway resistance several times leading to complete airway obstruction. History and clinical examination give clue to the diagnosis, which should be confirmed by imaging (particularly by computed tomography scan). Based on the severity of obstruction, it is managed either conservatively or surgically.
Keywords: Congenital nasal pyriform aperture stenosis, cyclical cyanosis, respiratory distress, solitary maxillary central incisor
|How to cite this article:|
Kumar N D, Kumaran A A, Balaji S, Anupriya R. Congenital nasal pyriform aperture stenosis: A rare cause of respiratory distress in newborn. J Clin Neonatol 2015;4:203-5
|How to cite this URL:|
Kumar N D, Kumaran A A, Balaji S, Anupriya R. Congenital nasal pyriform aperture stenosis: A rare cause of respiratory distress in newborn. J Clin Neonatol [serial online] 2015 [cited 2020 Dec 2];4:203-5. Available from: https://www.jcnonweb.com/text.asp?2015/4/3/203/159912
| Introduction|| |
Congenital nasal pyriform aperture stenosis (CNPAS) is an uncommon cause of nasal obstruction in a neonate, which was first clinically described in 1989.  Bony overgrowth of the maxillary nasal process is responsible for this condition.  Clinical suspicion is based on difficulty in passing nasogastric (NG) tube, respiratory distress, difficulty in breast feeding, cyclical cyanosis relieved by crying. This anomaly can occur either as an isolated phenomenon or in association with midline defects like solitary median maxillary central incisor (SMMCI).  In this case report, we present an of CNPAS with solitary median maxillary central incisor (SMMCI).
| Case Report|| |
A full-term female baby, the 2 nd child of nonconsanguineous parents, was delivered by Elective caesarean section. The antenatal period was uneventful. Baby cried at birth, weighed 3 kg, with an APGAR of 1' 8/10 5' 9/10. On examination baby had respiratory distress with a Downey's score of 3/10, shallow palate [Figure 1] and NG tube reached stomach with difficulty. Baby was admitted in Neonatal Intensive Care Unit for respiratory distress, and her sepsis screening was negative, X-ray chest and abdomen showed features suggestive of transient tachypnea of newborn and NG tube confirmed to reach the stomach.
Baby was treated with oxygen and intra venous fluids. At 30 h of life, distress settled, and baby was started on feeds. Baby had difficulty in breast-feeding and developed cyclical cyanosis, which was relieved by crying. Since there was difficulty in passing the 5 French NG tube through both nostrils and upper airway obstruction was strongly suspected, differential diagnosis of choanal atresia, CNPAS, nasopharyngeal encephalocele and congenital nasal tumors were thought of and computed tomography (CT) scan was planned to evaluate upper airway.
The CT scan showed medial approximation of nasal process of maxilla suggestive of CNPAS [Figure 2], single maxillary central incisor/mega incisor [Figure 3] and triangular hard palate, CT brain was normal. The neonate was conservatively managed with topical nasal decongestants.
|Figure 2: Axial computed tomography scan (white arrow) shows medial approximation of nasal process of maxilla suggestive of congenital nasal pyriform aperture stenosis|
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|Figure 3: Axial computed tomography scan (white arrow) shows triangular hard palate with solitary maxillary central incisor|
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| Discussion|| |
The reported incidence of CNPAS was 1 in 5000-8000 live births and occurrence of SMMCI was 1 in 50,000 live births. 
Neonates are obligate nasal breathers till 6-8 weeks of life, any form of nasal obstruction will lead to respiratory distress at this age and needs immediate intervention.  CNPAS is a rare cause of congenital upper airway obstruction in a neonate. The most narrow part of the nasal cavity, nasal pyriform aperture is a peer shaped opening bounded superiorly by a nasal bone, laterally by nasal process of maxilla and inferiorly by palatine process. 
Congenital nasal pyriform aperture stenosis, usually presents at birth with respiratory distress, cyclical cyanosis, difficulty in feeding or with associated anomalies as holoprosencephaly, midline facial defects, clinodactyly, pituitary dysfunction and most commonly megaincisor (75% of cases).  The diagnosis can be made with contiguous axial CT scan sections in a plane parallel to the hard palate demonstrating narrowing of the pyriform aperture and free posterior choanae.  Typical findings are narrowed bony inlet, triangular shaped palate, bony overgrowth in the nasal process of maxilla and abnormal dentition like megaincisor.  The normal width of pyriform sinus in the age group 0-6 months is 8.8-17.2 mm. Each pyriform aperture width < 3 mm or whole of the pyriform aperture < 8 mm in term neonate at the level of the inferior meatus between the medial aspects of the nasal process of the maxilla is diagnostic of CNPAS. 
SMMCI arises from 4 th month of fetal development, by itself is not a health issue for the neonate, and it is usually left untreated. In both primary and secondary dentition, it develops in the midline of maxillary dental arch. Deletion of chromosome 7 and 8 are associated with SMMCI; these are the chromosomes, which carry the genes for holoprosencephaly and hence SMMCI is considered as a marker or microform of holoprosencephaly. Some reports suggest Sonic Hedgehog mutation in patients with SMMCI. Thus, occurrence of SMMCI with CNPAS mandates magnetic resonance imaging brain to rule out the associated features of holoprosencephaly sequence and pituitary disorders. 
Once the diagnosis of CNPAS has been established, initial conservative treatment with topical nasal decongestants, intranasal 0.1% dexamethasone drops, 3.5 mm endotracheal tube stent, humidification of air, insertion of oral airway and lavage feeding are tried.  When conservative management fails, surgical treatment with widening of bony inlet via sublabial approach is performed with possible complications of septal perforation, columellar necrosis and synechiae. ,
| Conclusion|| |
Evaluation of neonatal upper airway obstruction needs a multidisciplinary approach. As the prognosis is good with treatment, early recognition and timely intervention is necessary. This case is presented to increase the awareness about this condition, to highlight the typical findings of CNPAS while evaluating the upper airway obstruction and to stress on the role CT in diagnosing CNPAS.
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[Figure 1], [Figure 2], [Figure 3]