This article has Open Peer Review reports available.
Clinical course and implications of congenital nasal pyriform stenosis and solitary median maxillary central incisor in a newborn: a case report
© Günther et al.; licensee BioMed Central Ltd. 2014
Received: 21 January 2014
Accepted: 22 April 2014
Published: 20 June 2014
Congenital nasal pyriform aperture stenosis and solitary median maxillary central incisor are uncommon anomalies and are associated with further malformations. Solitary median maxillary central incisor itself has initially no impact on a child’s health, but congenital nasal pyriform aperture stenosis is a potentially life-threatening condition.
A Caucasian baby boy showed severe dyspnoea and was intubated orotracheally. Multiple anomalies were detected, including urogenital and craniofacial malformations. Computed tomography scans revealed congenital nasal pyriform aperture stenosis with a diameter of 4.9mm and a solitary median maxillary central incisor. A 3.0mm tube was inserted in his left nasal cavity, and the baby was able to breathe sufficiently and spontaneously. The nasal tube was removed after seven days, and the baby was discharged under application of decongestant drops. After seven months, the baby was readmitted with respiratory distress, and surgery was carried out using an intraoral sublabial approach. The stenotic area of the pyriform aperture was widened, and 3.0mm tubes were inserted in both nasal cavities for 10 days. Over a period of six months, no further respiratory distress has occurred.
The decision to perform surgery was delayed since the baby’s nasal breathing was adequate as a result of the insertion of a nasal tube. Since treatment depends on the severity of symptoms, it is appropriate in some cases to take a conservative approach at first, and to keep surgery as a last resort. Once a conservative approach has been selected for congenital nasal pyriform aperture stenosis, awareness of the life-threatening nature of the condition should be kept in mind, and a surgical approach must still be taken into account.
Congenital nasal pyriform aperture stenosis (CNPAS) is an unusual neonatal upper airway obstruction, which was first described in 1989 . The true incidence is still unknown. It is estimated that CNPAS occurs at a frequency of about one-fourth to one-third of choanal atresia, which in turn has a reported incidence of 1 in 5,000 to 8,000 live births [2, 3]. CNPAS can lead to life-threatening conditions since newborns are obligate nasal breathers in the first weeks of their life. Hence, early diagnosis is vital for the appropriate management of the condition, which could be either conservative or surgical, and depends on the severity of symptoms. Associated malformations include hypopituitarism, and craniofacial, cardiac and urogenital anomalies . Furthermore, studies have confirmed the suggestion that CNPAS even represents a manifestation of holoprosencephaly (HPE) . A solitary median maxillary central incisor (SMMCI) can be detected in up to 60 percent of CNPAS cases. SMMCI is a rare dental anomaly that has been considered to be a part of a complex disorder consisting of multiple, mainly midline defects of development. It results from unknown factors operating in utero about the 35th to the 38th day from conception and is estimated to occur in 1 in 50,000 live births. SMMCI can be found in patients with specific chromosomal abnormalities, including missense mutation in the Sonic Hedgehog (SHH) gene (I111F) at 7q36. In accordance with CNPAS, SMMCI may include microforms and the full spectrum of HPE as well [6–8].
In this case report, we present the clinical course of a newborn with CNPAS and SMMCI, and discuss the management options. Our experience may contribute to further interdisciplinary decision-making for these rare conditions.
On postoperative day 3, orotracheal extubation was possible at the intensive care unit without complications. The nasal tubes were changed after five days and completely removed on postoperative day 10. Nasal decongestant drops were applied for another 14 days. Monitoring oxygen saturation by day and by night revealed no significant decreases even in the supine position, and nutrition without breathing breaks was possible. The baby was discharged and given appointments for close follow-up. Over a period of six months after surgery, the baby had no further symptoms of respiratory distress and was admitted to the pediatric surgery department for therapy for his other malformations.
In the present case report, it remains unclear whether CNPAS was accompanied by an SMMCI or vice versa. However, both malformations raise the possibility of further associated anomalies. Since neonates are obligatory nasal breathers, the possible life-threatening condition of a CNPAS needs immediate intervention after birth. Hence, the focus is primarily more on this malformation than on SMMCI. In general, management of CNPAS depends first on the overall prognosis of the patient, and second on the severity of obstruction. Patients with poor overall prognosis should be managed conservatively with an oropharyngeal airway. In patients with a good outlook, the choice of treatment is conservative for those with less severe obstruction, and surgical correction for those with complete obstruction . The diagnosis of CNPAS is based on clinical evaluation, including nasal endoscopy and, especially, CT scans. The inability to pass a 5 French (F) catheter (outer diameter 1.67mm) and a radiographically measured pyriform opening less than 8 to 10mm in a full-term newborn are considered as a relevant stenosis. In turn, the aperture is considered satisfactory when it allows for the passage of an endotracheal tube stent with an inner diameter of 3.5mm [5, 9].
In the present case, the decision for surgery was delayed for a considerable time since nasal breathing was adequate after initial intubation of the left nasal cavity, and later even without a nasal tube. As a result of growth, CNPAS became clinically apparent again at an age of seven months, and rendered surgery mandatory. However, since treatment depends on the severity of symptoms in borderline cases as presented in this report, it is appropriate to use the conservative therapeutic spectrum at first and keep surgery as the last resort. In general, surgical removal of the external bony margins of the pyriform aperture is successful regarding normal nasal breathing and pyriform aperture growth after surgery in further follow-up assessments. No bony restenosis of CNPAS with the necessity of a second operation is described in the literature [9, 10]. However, reservation toward a primary surgical approach has been supported by results of a recent retrospective case note review. From a total of 10 identified cases of CNPAS, only 50 percent had to be managed surgically . Accordingly, in another case series, 0.1 percent intranasal dexamethasone drops were used successfully for conservative treatment in three out of five patients . Furthermore, possible complications of a surgical approach have to be evaluated, including columellar necrosis, which has been described in one out of 20 surgical cases, development of synechiae, and septal ulceration with septal perforation [6, 10]. With respect to the reported complications following a surgical approach, in our case we discontinued the attempt to install larger tubes, since the small columnella became cyanotic. However, to reduce recurrence and scar-related stenosis after surgery, the use of nasal stents is recommended. To avoid septal complications and scarring after surgery, we changed nasal tubes after five days, and removed tubes not later than day 10, in accordance with the recommendations given in the literature in cases of isolated CNPAS . Another reason for a delay in surgery in a considerable number of cases without a life-threatening condition is to gain valuable time until general anesthesia can be carried out. Of course, intraoperative hemorrhage within widening the pyriform aperture should not be comparable with hemorrhage within surgery on craniosynostosis. However, incidence of intraoperative hypoxemia increases with younger age, with the highest incidence in neonates, and is further complicated by syndrome-specific issues .
SMMCI was previously considered to be a simple midline defect of the dental lamina, but it is now recognized as a possible predictor of HPE of varying degrees in the proband, in members of the proband’s family, and in the family’s descendants . Hence, genetic counseling is mandatory in these cases. The SMMCI tooth itself is a real central incisor tooth, although of unusual crown form, but not a supernumerary tooth like a mesiodens. It develops and erupts precisely in the midline of the maxillary dental arch. Only in very rare cases, does SMMCI contribute to the pyriform aperture stenosis. Otherwise, it is mainly an esthetic problem, managed by combined orthodontic, prosthodontic and oral surgical treatment. Alternatively, it can be left untreated .
Once a conservative approach is selected for the treatment of CNPAS, awareness of the life-threatening nature of this malformation should be kept in mind. Since respiratory distress due to CNPAS can also become apparent during a child’s further growth, the immediate need for a surgical approach must still be taken into account. Therefore, close follow-up is highly recommended.
Written informed consent was obtained from the parents of the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.
- Brown OE, Myer CM, Manning SC: Congenital nasal pyriform aperture stenosis. Laryngoscope. 1989, 99: 86-91.View ArticlePubMedGoogle Scholar
- Hengerer AS, Brickman TM, Jeyakumar A: Choanal atresia: embryologic analysis and evolution of treatment, a 30-year experience. Laryngoscope. 2008, 118: 862-866. 10.1097/MLG.0b013e3181639b91.View ArticlePubMedGoogle Scholar
- Thomas EM, Gibikote S, Panwar J, Mathew J: Congenital nasal pyriform aperture stenosis: a rare cause of nasal airway obstruction in a neonate. Indian J Radiol Imaging. 2010, 20: 266-268. 10.4103/0971-3026.73539.View ArticlePubMedPubMed CentralGoogle Scholar
- Visvanathan V, Wynne DM: Congenital nasal pyriform aperture stenosis: a report of 10 cases and literature review. Int J Pediatr Otorhinolaryngol. 2012, 76: 28-30. 10.1016/j.ijporl.2011.09.016.View ArticlePubMedGoogle Scholar
- Hui Y, Friedberg J, Crysdale WS: Congenital nasal pyriform aperture stenosis as a presenting feature of holoprosencephaly. Int J Pediatr Otorhinolaryngol. 1995, 31: 263-274. 10.1016/0165-5876(94)01096-G.View ArticlePubMedGoogle Scholar
- Van Den Abbeele T, Triglia JM, François M, Narcy P: Congenital nasal pyriform aperture stenosis: diagnosis and management of 20 cases. Ann Otol Rhinol Laryngol. 2001, 110: 70-75.View ArticlePubMedGoogle Scholar
- Nanni L, Ming JE, Du Y, Hall RK, Aldred M, Bankier A, Muenke M: SHH mutation is associated with solitary median maxillary central incisor: a study of 13 patients and review of the literature. Am J Med Genet. 2001, 102: 1-10. 10.1002/1096-8628(20010722)102:1<1::AID-AJMG1336>3.0.CO;2-U.View ArticlePubMedGoogle Scholar
- Hall RK: Solitary median maxillary central incisor (SMMCI) syndrome. Orphanet J Rare Dis. 2006, 1: 12-10.1186/1750-1172-1-12.View ArticlePubMedPubMed CentralGoogle Scholar
- Sesenna E, Leporati M, Brevi B, Oretti G, Ferri A: Congenital nasal pyriform aperture stenosis: diagnosis and management. Ital J Pediatr. 2006, 38: 28-View ArticleGoogle Scholar
- Devambez M, Delattre A, Fayoux P: Congenital nasal pyriform aperture stenosis: diagnosis and management. Cleft Palate Craniofac J. 2009, 46: 262-267. 10.1597/07-182.1.View ArticlePubMedGoogle Scholar
- Collins B, Powitzky R, Enix J, Digoy GP: Congenital nasal pyriform aperture stenosis: conservative management. Ann Otol Rhinol Laryngol. 2013, 122: 601-604.PubMedGoogle Scholar
- de Graaff JC, Bijker JB, Kappen TH, van Wolfswinkel L, Zuithoff NP, Kalkman CJ: Incidence of intraoperative hypoxemia in children in relation to age. Anesth Analg. 2013, 117: 169-175. 10.1213/ANE.0b013e31829332b5.View ArticlePubMedGoogle Scholar
- Hall RK, Bankier A, Aldred MJ, Kan K, Lucas JO, Perks AG: Solitary median maxillary central incisor, short stature, choanal atresia/midnasal stenosis (SMMCI) syndrome. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1997, 84: 651-662. 10.1016/S1079-2104(97)90368-1.View ArticlePubMedGoogle Scholar
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.