What is the most indicative method for suggesting choanal atresia?

The most indicative method for suggesting choanal atresia is the failure to pass a catheter through the nasal passages. This situation is highly relevant because one of the primary presentations of choanal atresia in newborns is respiratory distress or difficulty breathing, particularly when they are feeding or during quiet sleep.

When a catheter is inserted into an infant's nose, it is typically expected to pass through to the oropharynx. In the case of choanal atresia, a bony or membranous obstruction will prevent the catheter from reaching its destination, indicating a blockage. This physical finding can prompt further investigation or imaging studies.

The physical examination and other imaging techniques, like a CT scan or chest X-ray, might reveal additional information about the anatomy or rule out other conditions, but the failure to pass a catheter is the direct and specific test that suggests the presence of choanal atresia most clearly and immediately.