Laura H. Swibel Rosenthal, MD
When the back of the nose is not open or not communicating with the rest of the airway this is called choanal atresia. It is a congenital condition that occurs in about 1 in 6000 to 8000 live births. The exact reason for the anomaly is unknown and probably multifactorial, or a mix of genetic and environmental causes. When the nasal airway develops, it starts at the level of the skin of the face, where two indentations develop. These pits become deeper and deeper and eventually connect with the oral airway above and behind the palate. If this canalization is incomplete, the result is choanal atresia. (See Figure 1, below) For unknown reasons, choanal atresia seems to happen about twice as often in males as in females. It occurs on only one side about twice as often as on both sides. (About 1/3 are bilateral and 2/3 are unilateral.)
Figure 1: Endoscopic view of the back of the normal nose. The opening is called the choana. The space behind the nose is the nasopharynx. Adenoids (A), lumpy pink tissue similar to tonils, can normally be seen in the nasopharynx. In choanal atresia, this area is completely closed. All that can be seen is tissue similar in appearance to the floor of the nose (F).
SIGNS AND SYMPTOMS OF UNILATERAL CHOANAL ATRESIA
When unilateral, the right side is affected more often than the left. If the atresia is only on one side, sometimes it is identified at birth but it can go unnoticed for a few years. Most commonly, children will have chronic thick drainage from one side of the nose.
SIGNS AND SYMPTOMS OF BILATERAL CHOANAL ATRESIA
If the atresia is present on both sides, it is much more likely that the newborn infant will become symptomatic with significant difficulty breathing and feeding. Patients may have noisy breathing, turn blue while sleeping or feeding, and aspirate milk. When the patient awakens, coughs or cries the oral airway will open again and symptoms will often temporarily resolve. Feeding slowly can allow the baby to breathe between swallows. However, a feeding tube is often placed from the oral cavity into the stomach to make sure that the patient safely receives adequate feeds.
INITIAL TREATMENT OF BILATERAL CHOANAL ATRESIA
Bilateral choanal atresia can be a life-threatening situation. In an emergency, an oral airway or short tube along the top of the tongue can be placed so that the airway stays open. Patients will often require an intubation or tracheostomy. Intubation is when a breathing tube is placed from the mouth into the trachea or main airway. A tracheostomy is an airway through the skin and soft tissue of the neck. One of the first signs in the delivery room or neonatal intensive care unit (NICU) that a patient may have a bilateral choanal atresia is the inability to pass a small catheter down either side of the nose into the stomach. Similarly, a flexible endoscope may also be passed into the nose at the patient’s bedside to examine the inside of the nose and confirm the anatomy. Once an airway is established and the patient is stable, a CT scan (computed tomography) and possibly and MRI (magnetic resonance imaging) may be obtained to confirm the choanal atresia or identify other reasons for the patient’s symptoms.
SURGERY TO REPAIR OR OPEN THE CHOANA
The choanal atresia can be repaired or opened with a surgical procedure. 70 to 90% of choanal atresia involves bone and the soft tissue covering the bone. Only in a small portion of cases is the narrowing composed of only soft tissue and no bone. There are multiple techniques that can be used during surgery, but most often an endoscopic approach is used. With an endoscopic approach there are no incisions on the face or the palate (the roof of the mouth). The procedure is done through the nostrils. The bone and soft tissue that is blocking the opening is taken down until it is open to the area where it connects with the mouth. This area is called the nasopharynx. (It is above the oropharynx, the area behind the oral cavity. These spaces are then contiguous.) An “open” approach can be used in which an incision is made into the palate from the oral cavity to access the narrowing in the nose. After the atresia is opened, the palate is then closed. In either case, endoscopic or open, a temporary stent may or may not be placed to keep the newly created choana open. It is possible that the opening may begin to close, with or without a stent. More than one surgery is often necessary to try to keep the nasal airway open. (See Figures 2 and 3)
Figure 2: This is a similar view as in Figure 1. This endoscopic view shows a stenosis or narrowing of the choana. In a complete obstruction, there would be no hole, as there is above. The stenosis in this patient is present about one or two years after a single attempt at repair in infancy.
Figure 3: The choana is shown immediately after opening during endoscopic surgery. The nose heals quickly. There may be mild to moderate pain for a few days. Saline spray is used at home to help rinse the nose and keep it clean.
Once the atresia is repaired and well-healed, patients who required a tracheotomy can usually have the tracheotomy removed as long as there are no other problems for which the tracheotomy would be necessary. The timing of removal of the tracheotomy will vary by patient.
CHOANAL ATRESIA ASSOCIATED WITH OTHER CONGENITAL ANOMALIES
Choanal atresia usually occurs in the absence of any other anomalies or syndromes. However, there are syndromes associated with choanal atresia for which every patient should be evaluated. This is especially true for those with bilateral choanal atresia, as other congenital anomalies are more common in those affected bilaterally. The most common syndrome associated with choanal atresia is CHARGE syndrome. Patients with this may have other findings such as coloboma (a slit in the eyelid or iris), heart anomalies, atresia of the choana, retardation of growth or development, genital or urinary anomalies, and ear problems (malformation and/or hearing loss). About 60% of patients with CHARGE syndrome have bilateral choanal atresia. This particular syndrome is genetic, inherited in a dominant pattern. One of the patient’s parents is usually affected, although the parent can be more or less affected, meaning that the symptoms or features may be more or less noticeable. Genetic mutations can also be sporadic (not inherited) and they can be mosaic (affecting some of the patient’s cells and not others). In this case the neither of the patient’s parents would have the mutation or be affected. Mutations in the CHD7 gene should be tested and are identified in 75% of patients with CHARGE. The remaining 25% of patients may have a mutation in another gene or no genetic mutation.
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