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The nasal choanae are paired openings that connect the nasal cavity with the nasopharynx. Choanal atresia is a congenital condition characterized by occlusion of these openings by membranous soft tissue, bone, or a combination of both due to failed recanalization of the nasal fossae during fetal development. Unilateral occurrences present with mucopurulent discharge on the affected side, while bilateral defects prevent normal breathing in neonates. Since newborns are obligate nasal breathers, establishing an airway in patients with bilateral obstruction is an acute otolaryngologic emergency. Choanal atresia is diagnosed through clinical evaluation and imaging, with nasal endoscopy or computed tomography confirming the condition and potentially finding associated anomalies. Bilateral cases require immediate airway management, such as oral airway placement or intubation, with definitive treatment involving surgical repair, typically through transnasal endoscopic techniques. Postoperative care includes monitoring for complications like restenosis and ensuring nasal patency. Prognosis is favorable with timely intervention, though associated conditions, such as the syndrome of coloboma, heart defects, atresia choanae, growth retardation, genital abnormalities, and ear abnormalities (CHARGE), may influence outcomes. This activity for healthcare professionals is designed to enhance learners' proficiency in evaluating and managing choanal atresia. Participants gain a broader understanding of the condition's etiology, risk factors, pathophysiology, clinical presentation, and best diagnostic and therapeutic strategies. Greater competence equips clinicians to collaborate effectively within an interprofessional team caring for affected individuals, improving outcomes. Objectives: Compare the presenting features of unilateral and bilateral choanal atresia. Implement a clinically sound diagnostic approach for suspected choanal atresia cases. Apply individualized, evidence-based interventions for choanal atresia and its potential complications. Implement effective strategies to improve care coordination among interprofessional team members to facilitate positive outcomes for patients with choanal atresia. Access free multiple choice questions on this topic.

First described in 1755 by Johann Roderer, choanal atresia is a disorder characterized by the congenital absence of the nasal choanae, the paired openings that connect the nasal cavity with the nasopharynx (see Image. Choanal Atresia on Nasal Endoscopy).[1] This condition stems from the failure of nasopharyngeal recanalization during fetal development and can involve soft tissue, bone, or both. Choanal atresia may be complete, lacking communication between the nasal cavity and nasopharynx, or partial, with only choanal stenosis.[2] Unilateral atresia often presents with unilateral mucopurulent discharge but may not be clinically evident until the child is older if they can breathe through the contralateral side.[3] Bilateral atresia manifests in neonates as respiratory distress immediately after birth due to the inability to breathe, as newborns are obligate nasal breathers. Bilateral choanal atresia is an acute otolaryngologic emergency warranting immediate airway management.[4][5][6]

The choanae develop between the 3rd and 7th embryonic weeks, following the rupture of the vertical epithelial fold between the olfactory groove and the stomodeum, the roof of the primary oral cavity.[7] While the precise mechanisms remain elusive, the following theories have been proposed to explain the pathogenesis of choanal atresia: Persistence of the buccopharyngeal membrane: The buccopharyngeal or oropharyngeal membrane develops in early embryogenesis and is well-formed by fetal day 25. This membrane is comprised of endoderm and ectoderm and separates the primordial mouth and pharynx. The buccopharyngeal membrane normally ruptures between the 3rd and 7th fetal weeks, connecting the mouth to the rest of the gut.[8] Incomplete or failed rupture of this membrane may lead to choanal atresia, pharyngeal stenosis, or oral synechiae formation.[9][10] The c-Jun N-terminal kinase signaling pathway, which is related to programmed apoptosis, has been implicated in the persistence of the buccopharyngeal membrane.[11] Persistence of the nasobuccal membrane of Hochstetter: The early nasal cavity begins with neural crest cell migration from the dorsal neural folds in fetal week 3.[12] Nasal pits subsequently form in weeks 5 and 6 and embed with mesenchyme. The resultant separation is the nasobuccal membrane (of Hochstetter, which ruptures after week 6 to form the primitive nasal cavity with choanae.[13] Incomplete resorption of the nasopharyngeal mesoderm: The complex interplay between ectodermal, endodermal, mesenchymal, and neural crest cell-derived structures to develop the normal nasal cavity and nasopharynx takes place over fetal weeks 3 to 11.[14] The normal flow of mesoderm, particularly between weeks 4 and 11, includes deposition and resorption. Failed or incomplete mesoderm resorption may lead to persistent bone or soft tissue within the developing choanae, preventing normal communication between the nasal cavity and the nasopharynx.[15][16]

Incomplete resorption of the nasopharyngeal mesoderm: The complex interplay between ectodermal, endodermal, mesenchymal, and neural crest cell-derived structures to develop the normal nasal cavity and nasopharynx takes place over fetal weeks 3 to 11.[14] The normal flow of mesoderm, particularly between weeks 4 and 11, includes deposition and resorption. Failed or incomplete mesoderm resorption may lead to persistent bone or soft tissue within the developing choanae, preventing normal communication between the nasal cavity and the nasopharynx.[15][16] Local misdirection of neural crest cell migration: Neural crest cells delaminate from the ectoderm layer in an epithelial-mesenchymal transition early in embryogenesis and migrate throughout the developing embryo.[17] Neural crest cells migrate into the pharyngeal arches in week 4, ultimately forming portions of the bony craniofacial skeleton. Aberrant migration of these cells has been implicated in the formation of bony components in atretic choanae.[18] Molecular and genetic studies supporting these theories give further insights into the pathogenesis of choanal atresia.[19][20]

The overall reported incidence of choanal atresia varies. A large series from California, USA reported an incidence of 0.82 per 10,000 live births, but the most often quoted figures range from 1 in 5,000 to 1 in 8,000 live births. The CHARGE Syndrome Foundation has quoted the same range.[21][22][23] Choanal atresia is more often unilateral than bilateral (60% vs. 40%), though some recent studies suggest a nearly 1:1 ratio.[24] Historically, choanal atresia was described as occurring more frequently in female than in male individuals (ratio 2:1), though more recent evidence refutes this predisposition.[25] Currently, the condition is most widely accepted as having an equal sex distribution.[16]

Current knowledge of the pathophysiology of neonatal respiration has led to the conclusion that infants are obligate nasal breathers, except when crying.[26] This tendency is due to the newborn's elevated laryngeal position as compared to that of the adult. When a neonate swallows, the larynx elevates to meet the nasopharynx, creating a seal between the soft palate and the lateral walls of the nasopharynx. During inspiration, the neonate draws the tongue backward, creating a vacuum in the oropharynx that moves the floor of the mouth's soft tissue upward and backward toward the soft palate. During expiration, airway pressure pushes the soft palate forward against the tongue and soft tissue in the mouth, further obstructing the oral airway.[27][28] Thus, infants with bilateral choanal atresia experience asphyxia and severe respiratory distress during quiet breathing when the mouth remains closed, particularly during sleep or feeding. Cyanosis develops but is relieved by crying or gasping, as widely opening the mouth alleviates the obstruction. Approximately 50% of babies born with choanal atresia have a defined associated syndrome, which may have a known genetic mechanism. Among the most common are the following: Abnormal CHD7 gene: Syndrome of coloboma, heart disease, atresia choanae, mental retardation, genitourinary abnormalities, and ear deformities (CHARGE) [29] Mutant FGFR2 gene: Crouzon syndrome [30] Deletion in 22q11.2: DiGeorge syndrome [31] Aberrant TCOF1 gene: Treacher-Collins syndrome [32] Mutant FGFR1 or FGFR2 gene: Pfeiffer syndrome [33] No apparent genetic cause: Amniotic band syndrome [34]

Postnatal history and physical examination are critical to diagnosis. The clinical presentation of choanal atresia varies from acute, life-threatening airway obstruction to chronic, recurrent nasal discharge on the affected side, depending on whether the abnormality is unilateral or bilateral. Infants with bilateral choanal atresia experience acute respiratory distress marked by cyanosis that resolves with crying but returns during rest (paradoxical cyanosis). These symptoms typically appear at birth or shortly after, depending on the severity of the atresia or stenosis. In milder cases, feeding difficulties may serve as the initial indication, with affected infants showing progressive airway obstruction and choking episodes during feeding due to the inability to breathe and feed simultaneously.[35] Infants with unilateral choanal atresia rarely develop respiratory distress, as one choana remains patent. The condition most commonly presents with purulent nasal discharge and obstruction on the affected side. In some cases, the diagnosis may be delayed until adulthood due to nonspecific symptoms, such as unilateral nasal obstruction, snoring, and recurrent sinusitis. Choanal atresia often occurs alongside other anomalies, with CHARGE syndrome being the most common. This syndrome is characterized by the presence of coloboma, heart disease, choanal atresia, growth and developmental delays, genital hypoplasia, and ear anomalies. A comprehensive physical examination is essential in patients with choanal atresia, with a low threshold for performing cardiac and renal imaging and an audiogram.[36][37][38] The hallmark finding on physical examination is nasal obstruction or stenosis. Anterior rhinoscopy should be performed, although persistent rhinorrhoea can make assessing the posterior nasal cavity challenging. Examination is essential to rule out other conditions that can mimic choanal atresia, including severe septal deviation, turbinate hypertrophy, nasal polyposis, and nasal tumors. Placing a dental mirror beneath each nostril to check for fogging during exhalation can be particularly helpful, especially after using a topical nasal decongestant. Nasal endoscopy is considered the gold standard for diagnosis, as it distinguishes between conditions mimicking choanal atresia and determines the degree of stenosis in cases with partial involvement.

After completing a thorough physical examination and addressing any airway problems, imaging may be used to determine the extent and composition of the atresia. Computed tomography is the preferred modality, as it effectively distinguishes between bony and soft tissue components of the atresia. Magnetic resonance imaging is generally unnecessary unless an encephalocele or another skull base defect is suspected. Routine imaging is often not required for unilateral atresia, though this decision is typically based on the surgeon's preference.[39]

The mainstay of treatment for choanal atresia is surgery, focusing on restoring choanal patency, preserving craniofacial development, minimizing invasiveness, and preventing recurrence. Surgical intervention is less urgent for unilateral choanal atresia than for bilateral cases and may be delayed until school age when the anatomy more closely resembles that of adults.[40] Whenever feasible, surgery is ideally postponed until at least 6 months of age, though severe bilateral cases may require earlier intervention. A nasal saline spray can help with nasal toileting while awaiting definitive surgery. Acute care for infants with bilateral choanal atresia and respiratory distress involves placing an oral airway device, such as a Guedel or other oropharyngeal airway. Alternatively, a McGovern nipple with the end cut off may be used to keep the mouth open. This measure is temporary, as definitive endotracheal intubation is required to stabilize the airway in preparation for urgent surgical repair. Historically, 5 surgical approaches have been described: transpalatal, transeptal, sublabial, transantral, and transnasal.[41] The transpalatal approach was the most frequently used method until the development of the endoscopic endonasal approach, which is now the standard of care for nearly all cases.[42] Endoscopic techniques offer improved outcomes with fewer complications compared to traditional open procedures. This approach allows direct visualization of the atretic segment, which is then perforated with rigid instruments or drilled out if bone is present. The overlying mucosa is redraped to ensure the patency of the neochoana. Septal mucosal flaps may be used similarly to maintain this patency.[43] The use of choanal stenting and mitomycin C as adjuncts to prevent restenosis remains controversial due to a lack of strong supporting evidence.[44] More recently, balloon dilatation combined with long-term stenting has been used for membranous atresia, but its long-term effectiveness compared to formal surgical repair is still uncertain.[45]

The differential diagnosis of choanal atresia includes the following: Antrochoanal polyp Chordoma Deviated nasal septum Dislocated nasal septum Hematoma Isolated piriform aperture stenosis Nasal dermoid Nasolacrimal duct cyst Turbinate hypertrophy Tumor Encephalocele A thorough evaluation of these potential conditions helps guide appropriate treatment strategies.

The overall prognosis for choanal atresia is very good. However, bilateral cases must be recognized early and definitively treated emergently if respiratory compromise is present. The prognosis of any concurrent underlying syndrome or genetic condition primarily drives the overall outlook for patients. If none are present, normal life expectancy and development are expected.[46]

Recurrence is the primary complication of choanal stenosis, with 20% to 30% of cases requiring a second surgical intervention at some point. Risk factors for recurrence include bilateral involvement, age younger than 1 year at first repair, and the presence of an underlying syndrome.[47][48] Additional complications common after transnasal endoscopic surgery of any kind include orbital injury, skull base injury, bleeding, and infection.[49] Open transpalatal procedures carry similar risks, with the added potential for oronasal fistula and disruption of maxillary growth.[50]

Choanal atresia must be included in the differential diagnosis in a child with nasal or upper airway obstruction or respiratory distress. Bilateral choanal atresia should be considered in a neonate who becomes cyanotic during feeding and improves with crying. This condition, particularly in its bilateral form, constitutes a medical-surgical emergency requiring prompt treatment. Given the high association of this malformation with various congenital conditions, most notably CHARGE syndrome, evaluating for other inborn anomalies that may complicate the clinical picture is crucial. The endoscopic endonasal technique should be considered the first choice for surgical treatment of choanal atresia, as it provides direct access to the atretic plate, minimizes intraoperative bleeding, shortens hospitalization, and reduces morbidity.

An interprofessional team approach involving nurses and clinicians is necessary for the safe management of upper airway obstruction or respiratory distress. The team must include choanal atresia in the differential diagnosis. Bilateral choanal atresia should be considered in a neonate who turns cyanotic with feeding and improves with crying. Choanal atresia, especially in its bilateral form, is a medical-surgical emergency that requires timely intervention. Neonatal nurses should alert the team if any signs of this condition are present, and coordination with neonatologists and otolaryngologists is essential. As many of these infants may have CHARGE syndrome, an interprofessional approach to the evaluation is necessary. For stable infants, the endoscopic endonasal technique should be the first choice for surgical treatment. This approach provides direct access to the atretic plate, reduces intraoperative bleeding, shortens hospitalization, and lowers morbidity.