Choanal Atresia - Causes, Types, Diagnosis, and Treatment

Introduction

It is a congenital condition where blockage of the nasal pathway occurs due to obstruction of bone and membranous tissues. It occurs due to the recanalization of the nasal fossa during embryonic development. There is a failure of communication of the nasal cavity to the nasopharynx. It is a rare condition and has slightly more female predilection. It can be unilateral or bilateral. If it is unilateral choanal atresia, there is the presence of mucopurulent discharge; however, in bilateral choanal atresia, there is nasal breathing due to obstruction.

Choanal atresia is usually associated with various developmental anomalies such as Charge syndrome, Tessier syndrome, and Treacher Collins syndrome. It causes difficulty in the breathing of the child. Bilateral choanal atresia can be considered a pediatric emergency. There is the presence of marked asphyxia, increased chest retraction, and obstruction of oral airways. Treatment of choanal atresia is surgical and categorized choanal atresia is emergent and elective definitive.

What Is Choanal Atresia?

In the nasal cavity, there is the presence of two paired openings in the back. It helps in connecting the nasal cavity with the nasopharynx. A long narrow curved shelf of the bone protrudes into a nasal passage known as the posterior nasal choanae. The obstruction or narrowing of the nasal passage due to protuberance is known as choanal atresia. It results in difficulty in breathing. The blockage comprises membranous soft tissue, a bony surface, and a combination. It can affect one or both sides of the nose, and blockage can be partial or complete. It can occur in isolation, or it can occur with another developmental anomaly.

What Are the Causes Of Choanal Atresia?

Choanal atresia is a congenital condition in which the opening is occluded by membranous soft tissue and bone surface. Choanal atresia occurs when the tissue separation of the mouth and nose is developed correctly during fetal development. The fusion of the palatal process directs a posterior extension of nasal cavities. Membranes are thinning, separating the nasal cavity and oral cavity.

• The bucconasal membrane fails to rupture.

• Presence of medial outgrowth of the vertical and horizontal process.

• Abnormality of the mesodermal adhesions forming choanal area.

• The direction of mesodermal flow is abnormal, caused due to local factors.

• The buccopharyngeal membrane remains persistent during embryonic development.

What Are the Types of Choanal Atresia?

Following are the various types of choanal atresia.

• Based on the Side Involved:

  • Unilateral Choanal Atresia - In this type of choanal atresia, there is a blockage of only one nasal passage. It is commonly found in nasal atresia. Babies with this condition tend to breathe from another side of the nose to compensate.

  • Bilateral Choanal Atresia - In this type of choanal atresia, there is blockage of both nasal passages. As a result, the child cannot completely breath-form their nose after six weeks of birth. This emergency condition requires treatment as early as possible.

• Based on the Obstruction:

  • Complete Obstruction - In this type, the obstruction covers the whole surface of the nasal passage.

  • Partial Obstruction - In this type, the obstruction partially covers the surface of the nasal passage.

• Based on the Type of Blockage:

  • Bony Obstruction- In this choanal atresia, the blockage comprises only bones. Approximately thirty percent of choanal atresia are of bony types.

  • Membranous Obstruction- In this type of choanal atresia, the blockage is made up of membranous soft tissue.

  • Combination - In this type of choana atresia, there is a combination of soft tissue and a bony surface. It is commonly seen as choanal atresia.

What Are the Clinical Features of Choanal Atresia?

Following are the clinical features of choanal atresia according to their type.

• Unilateral Choanal Atresia

  • The child is asymptomatic during the neonatal period.

  • There is the presence of nasal discharge.

  • There is the presence of mouth breathing.

  • The child is unable to move air on one side.

  • The breathing of the child is noisy.

  • The child suffers from feeding difficulties.

• Bilateral Choanal Atresia

  • There is the presence of cyclic respiratory distress.

  • There is the presence of cyanosis.

  • There is the presence of noisy breathing.

  • There is the presence of feeding difficulties.

  • There is the presence of nasal drainage.

  • There is a presence of incoordination during swallowing.

  • There is the presence of aspiration due to upper airway disturbance.

  • Weight gain is poor in children.

  • There is the presence of gastroesophageal reflux.

  • Due to the loss of excessive secretion, there is the presence of hyponatremia.

How Choanal Atresia Is Diagnosed?

Following is the diagnostic test for choanal atresia.

• Computed Tomography - It provides 3-D imaging of the nasal structures.

• Nasal Endoscopy - A thin tube is inserted into the nose of the child to get a better view of the nasal structure.

How is Choanal Atresia treated?

Children with mild choanal atresia require close monitoring of their breathing problems. The nasal saline spray helps in keeping the nostril clear. In bilateral choanal atresia, a child needs immediate treatment as it is a medical emergency. The nasogastric tube is indicated until the surgery is performed. First, an endoscopy is performed in which a miniature viewing instrument is attached through the nose of the child for a good view and diagnosis. The bone and tissue which is causing obstruction are excised. Next, open surgery is performed in which the incision is given to the roof of the child's mouth. The blocking tissue is removed, and the stent is placed to open the airways. After a few weeks of the surgery, stents are removed.

Conclusion

If the child is born with choanal atresia, the parents should discuss the treatment option with the pediatrician. Parents should observe changes in the way the child breathing pattern of the child. The condition can be treated with a better prognosis with the help of surgery. Proper management helps the child with breathing difficulties, and the child can grow to live a happy, everyday life. If the child is suffering from additional developmental defects, they should be consulted by healthcare providers, and proper treatment should be done. Parents should observe their child's care, and treatment should be done early to improve the overall quality of life.