Choanal Atresia is a congenital anomaly of the anterior skull base characterized by closure of one or both posterior nasal cavities (the back of the nasal passage called choana is blocked by abnormal bony or soft tissue formed during fetal development). The condition occurs in 1 out of every 7,000 to 8,000 live births. Approximately 60% of reported cases are unilateral with a right-sided predominance. Bilateral choanal atresia is commonly associated with other congenital anomalies, such as coloboma, heart defects, choanal atresia, retarded growth, genitourinary abnormalities, and ear anomalies, which are present in approximately 50% of bilateral cases.

Diagnosis

Unilateral lesions may go undiagnosed until the child presents with persistent unilateral nasal drainage. Parents often report elaborate rituals of pulling strands of mucus from their child's nose. A few children have signs of respiratory distress at birth or develop obstructive sleep apnea during infancy. A simple test for unilateral choanal stenosis is to have the child attempt nose blowing with the opposite nostril occluded by external pressure. Failure to detect any air movement is suspicious for complete obstruction. Failure to pass a catheter through the occluded nostril can be misleading in the older child because there is enough space in the nasal cavity for the catheter to curl without passing into the nasopharynx. The otolaryngologist can visualize the choanal closure with a small, flexible scope passed through the nostril

Treatment

Bilateral choanal atresia requires airway support immediately after birth.In severe cases, longer term airway support with a tracheotomy may be needed until definitive repair can be performed safely. In cases where the skull base has a relatively normal shape and there are no cardiac contraindications to general anesthesia, bilateral choanal atresia should be repaired shortly after birth.Timing recommendations for repair of unilateral atresia vary in the literature. Repair at around 2 to 3 years of age is generally accepted.

Surgical procedures to correct choanal atresia can be broadly classified into transnasal and transpalatal approaches. The decision to use a transnasal versus a transpalatal approach rests on the surgeon's assessment of the choanal anatomy. The composition of the atretic plate, the depth and shape of the nasopharynx, and the presence of other anomalies are the most important factors. The transnasal approach requires less operative time and causes slightly less morbidity related to the incision. The transpalatal approach provides better exposure and more accurate bone removal. The palatal incision increases operative time and blood loss. The transpalatal approach probably reduces the risk of major vascular injury, intracranial complications, and restenosis.