Introduction
Congenital choanal atresia is a rare fetal developmental anomaly characterised by unilateral or bilateral obliteration of the posterior nasal opening by bone or soft tissue.Reference Anderhuber and Stammberger1 Approximately 60 per cent of choanal atresia cases are unilateral.Reference Gujrathi, Daniel, James and Forte2 The choanal obliterating plaque consists of bone in 30 per cent of cases and a bony-membranous mixture in 70 per cent. It is possible to encounter complete or incomplete obliteration.Reference Panda, Simhadri and Ghosh3, Reference Brown, Pownell and Manning4 Respiratory distress is seen in almost all bilateral congenital choanal atresia cases directly after birth.Reference Samadi, Shah and Handler5 The conventional view is that urgent surgery is life-saving in neonates because they are obligatory nasal breathers. Bilateral congenital choanal atresia is very rare in adulthood, and there are only a few cases reported in the literature.
Case report
A 53-year-old woman was referred to our clinic with difficulty in nasal breathing and continuous nasal discharge. Bilateral congenital choanal atresia was diagnosed by endoscopic examination (Figure 1) and paranasal sinus computed tomography (CT) (Figure 2). There were no other anomalies. The patient's past medical history revealed only chronic sinonasal problems with predominant nasal obstruction.
Fig. 1 Endoscopic, posterior view of the right nasal passage.
Fig. 2 Axial computed tomography head scan showing the patient's choanal atresia.
The patient was operated upon under general anaesthesia. Endoscopic examination along with palpation gave the impression that the bilateral plaques were of the mixed type. The overlying mucosa was elevated with a blade and elevator, and flaps were prepared. The membranous part of the atresia was opened by resection, and then the pterygoid process of the sphenoid bone and vomer were drilled out. Adequate bilateral choanal openings were created (Figure 3). Stents prepared from a size six silicon endotracheal tube were placed in the openings and fixed to the membranous septum with 3/0 silk sutures.
Fig. 3 Endoscopic view showing an adequate choanal opening following endoscopic surgery.
The post-operative period was uneventful, and the stents were removed six weeks later. Follow-up examination a year later revealed adequate choanal openings bilaterally.
Discussion
Bilateral congenital choanal atresia was first described by Roederer in 1755. The first reported case was from Germany, presented by Otto in 1830.Reference Anderhuber and Stammberger1, Reference Panda, Simhadri and Ghosh3
There are various theories about the embryopathogenesis of congenital choanal atresia. One states that the condition results from a persistent nasobuccal or buccopharyngeal membrane. Another theory proposes the abnormal migration of neural crest cells.Reference Anderhuber and Stammberger1, Reference Samadi, Shah and Handler5, Reference Voegels, Chung, Lessa, Lorenzetti, Goto and Butugan6 Most bilateral congenital choanal atresia cases are associated with other anomalies such as the ‘CHARGE’ syndrome, comprising coloboma, heart anomalies, growth retardation, and genital and ear anomalies.Reference Anderhuber and Stammberger1, Reference Panda, Simhadri and Ghosh3, Reference Samadi, Shah and Handler5
Bilateral congenital choanal atresia is characterised clinically by respiratory distress and cyanosis associated with feeding, which disappear when crying. This is because infants are compulsory nasal breathers in the first four months after birth, due to the high cervical localisation of the larynx at this age.Reference Panda, Simhadri and Ghosh3 For this reason, newborn bilateral congenital choanal atresia is an emergency condition for which early diagnosis and treatment are vital. Unilateral atresia, however, may often remain unrecognised for many years as its manifestations are non-specific, for example, rhinorrhoea and obstruction.
Congenital choanal atresia can be diagnosed by several methods. The easiest is to try to pass a small Nelaton catheter from the nose into the nasopharynx. It should be noted that the distance from the nares to the posterior nasopharyngeal wall is at least 2.5 cm. Rigid or flexible endoscopy, operational microscopy, a nasopharyngeal mirror or finger examination can also be used. Radiography, performed in the supine position with a radiopaque agent given through the nasal cavity, is another, rarely used option. Paranasal sinus CT is the standard evaluation method in diagnostic radiology.Reference Anderhuber and Stammberger1, Reference Panda, Simhadri and Ghosh3, Reference Samadi, Shah and Handler5 Computed tomography scanning enables the detection of bilateral or unilateral atresia, bony and membranous components, and other associated nasal abnormalities. Quantitative measurements made from the CT scan can also be used to guide surgical treatment of the condition.
Many techniques have been described for the management of congenital choanal atresia. Currently, the most commonly used method is an endoscopic transnasal approach. Transpalatal and trans-septal approaches are not often used. Endoscopic transnasal interventions should be preferred because they provide better visualisation and lower complication rates.Reference Singh7 Transpalatal and trans-septal approaches are not advised for newborns. Spinal canal injury, cerebrospinal fluid leakage and cavernous sinus injury are the most worrisome surgical complications. These complications are minimised by advanced endoscopic applications which provide a direct view, and by efficient bleeding control.
• Bilateral choanal atresia is rare in adults
• It should be considered in persistent nasal obstruction cases
We used a transnasal endoscopic approach in our case, and encountered no complications. In our patient, the atretic plaques were of the mixed type formed by both bone and membrane. Therefore, we used both soft tissue resection and bone drilling during surgical treatment.
Congenital choanal atresia is a rare entity in adulthood and few such cases have been reported. Yasar and Ozkul's description of a 51-year-old patient with congenital choanal atresia is one such report.Reference Yasar and Ozkul8 Our patient is notable in that she is to our best knowledge the oldest such patient reported in the recent English language literature.
