Article, Otorhinolaryngology
Epidemiology: Choanal atresia has an incidence of one in 5000 to one in 10,000 births and is more often unilateral than bilateral. The atresia is bony in 90% of cases and membranous in only 10%.
Symptoms: Bilateral choanal atresia is an acutely lifethreatening emergency because the neonate, except when crying, is an obligate nasal breather until about the sixth week of life. As a result, the infant experiences episodes of asphyxia at rest when its mouth is closed, especially during periods of sleep, and also during feeding. The resulting hypoxia is manifested by cyanosis, bradycardia, and an erratic respiratory rate with the mouth open or closed. Cyanosis that is present at rest and improves with exertion is called paradoxical cyanosis because of its opposite pattern relative to cyanosis with a cardiac cause. Unilateral choanal atresia may be manifested by a purulent nasal discharge on the affected side. Choanal atresia may be associated with various other anomalies, with fully developed cases presenting as the CHARGE syndrome ( coloboma; heart disease; atresia of the choanae; retarded growth, development and/or central nervous system anomalies; genital hypoplasia; ear
anomalies or deafness).
Diagnosis: Both choanae in newborns should be routinely catheterized in the immediate postnatal period (e.g., with the suction catheter) to exclude choanal atresia. The clinical suspicion of choanal atresia can be confirmed by examination with a rigid or flexible endoscope.
Treatment: The acute care of choanal atresia in asphyxia consists of intubation followed by
perforation of the atresia plate. Recurrent stenosis is prevented by inserting a stent and securing it with a suture (to prevent aspiration). The definitive surgical repair of bilateral choanal atresia is performed during the first weeks or months of life. Surgery for unilateral atresia can be postponed until school age, when the anatomy of the region is more similar to that encountered in adults.
Article, Otorhinolaryngology
Nasal endoscopy has become the most important and rewarding clinical examination method in rhinologic diagnosis.
Prerequisites: Nasal endoscopy requires practice because, unlike anterior rhinoscopy, it provides only close-up views of small intranasal areas. Besides rigid endoscopes, which are available in 4-mm and 2.8mm diameters and assorted viewing angles (e.g., 0, 30, 120), flexible endoscopes are also available for inspecting the nose and nasopharynx and exploring all of the pharynx and larynx in one sitting. Their main disadvantages compared with rigid scopes are their weaker light intensity and poorer image resolution. Also, it takes two hands to operate a flexible endoscope, while a rigid scope leaves one hand free for manipulating instruments. The patient is seated for the examination. As in anterior rhinoscopy, the preparations include decongestion of the nasal mucosa. A topical anesthetic
should also be applied. Diagnostic nasal endoscopy is performed with a 4-mm 30 telescope. The 2.8-mm scope is used only in a very narrow nasal cavity or in children.
Technique: First the examiner advances the endoscope into the nasopharynx and inspects the eustachian tube orifice, torus tubarius, posterior pharyngeal wall, and roof of the nasopharynx.
While the transnasal nasopharyngeal inspection can provide very detailed views (e.g., for early detection of nasopharyngeal cancer), it should still be supplemented by transoral postrhinoscopic endoscopy. Nasal endoscopy is particularly useful for evaluating the ostiomeatal unit, as this pathophysiologically important region generally cannot be adequately evaluated by anterior rhinoscopy alone. To inspect the middle meatus, the endoscope is first advanced toward the head of the middle turbinate. This should provide a good overview of the middle meatus. To advance farther into the ostiomeatal unit, the scope must negotiate the narrow passage between the uncinate process and the middle turbinate. Normally, this can be done only with a narrow-gauge scope (2.8 mm). The 4-mm endoscope can be used at this site only in patients who have had previous intranasal sinus surgery with resection of the uncinate process. Direct endoscopic inspection of the paranasal sinuses
is possible only to a limited degree. In some cases, the sphenoid sinus can be examined with a thin telescope passed through the natural ostium in the anterior sinus wall. If endoscopic exploration of the maxillary sinus is required (e.g., for a suspected tumor), it can be done either through the inferior meatus after perforating the lateral nasal wall or by a transfacial approach with incision of the maxillary sinus mucosa and perforation of its anterior wall.
Article, Otorhinolaryngology
Posterior rhinoscopy was formerly done to evaluate the nasopharynx and posterior nasal cavity (choanae, posterior ends of the turbinates, posterior margin of the vomer). With the establishment of endoscopic examination techniques in rhinology, this procedure, which requires special patient cooperation, is now considered obsolete.
