Evaluation and Advantage of Posteriorly Sited Curved Stent Tube in Congenital Bilateral Choanal Atresia View PDF

Choanal atresia is an obliteration, in newborns, of the airway at the level of posterior nasal aperture resulting in absence of connection between the nasal cavity and the aerodigestive tract. It was first described in 1755 by Johan Roderer. Congenital Choanal atresia is a rare condition (incidence 1 in 5000 - 8000 births live births) [1]. There are four popular theories regarding congenital choanal atresia development: (i) Persistence of the bucconasal membrane of Hochstetler, (ii) Misdirection of mesodermal flow secondary to local genetic factors, (iii) Persistence of a buccopharyngeal membrane from the foregut, and (iv) The abnormal persistence or location of mesodermal adhesions in the choanal region [2]. The blockage had thought to be either bony or membranous in origin. In reality, a mixed picture is usually seen (70% of cases) with the remainder being purely bony. Choanal atresia involving the right side is more common than in the left side. The newborn infant is an obligatory nose breather for the first few days after birth and has no ability to breathe through the mouth. Unilateral choanal atresia may go undiagnosed until childhood or even adulthood. Bilateral choanal atresia, on the other hand, poses a medical emergency immediately at birth causing respiratory distress and demanding immediate intervention. Unrecognized bilateral choanal atresia will almost certainly lead to death due to neonatal asphyxia. Choanal atresia is being two times more prevalent in females (2:1). And unilateral atresia is more common than bilateral atresia. This disorder can be transmitted as an autosomal recessive trait. Most cases of choanal atresia are isolated malformations, but the association with other congenital deformities is not exceptional [2, 3]. Boundaries of the atretic plates are the sphenoid bone superiorly, medial pterygoid lamina laterally, vomer medially, and horizontal portion of the palate inferiorly [3-5]. This anatomical knowledge of atrophic plates is highly valuable while performing surgery on these patients [2]. The diagnosis of the choanal atresia is done by the high suspension of clinical presentation then by doing physical exam, plain films and tomograms of the skull with radiopaque dye, CT scan [6]. Which is the single radiographic study of choice. The CT scan has proven valuable in the accurate assessment of both the normal and abnormal anatomy of the nasal cavity, posterior nasal choanae and nasopharynx [7, 8]. CT scan also helps exclude most if not all of the other diseases that could cause nasal obstruction of the newborn [9].
Establishing a secure airway is paramount, in many circumstances, this done prior to any investigative procedures. If the child has no underlying lung disease or laryngotracheal abnormalities, placement of an oral airway may be sufficient. An alternative to the conventional oral airway may be a feeding nipple cut at the end. Either of these should be secure by taping or tracheotomy ties placed around the head. Oxygen saturation monitoring can determine the efficacy of this maneuver and, if the child does not maintain adequate saturation levels, supplemental oxygen may be required. Alternatively, Oro-tracheal intubation with possible ventilator support may be required [5]. Feeding, usually gavages feeding is required until the child has learned to mouth breath. Then once the child learns the mouth breath, then he will swallow air and need frequent ‘breathing/burping breaks’ [6].

The technique for surgical repair of choanal atresia has evolved over the past 150 years. Through the transpalatal approach, To the currently favored endoscopic transnasal approach [1]. The ideal surgical procedure should provide adequate functional Choanal patencies, low rate of restenosis, avoid harm to any structure in development, enable shorter surgery and hospitalization time, and minimize morbidity and mortality. Many approaches have been used in the repair of choanal atresia, including transnasal approach, transpalatal approach and transseptal approaches nowadays, in unilateral atresia the endoscopic approach combining transnasal and posterior trans-septal technique considered as the gold standard [10].

Once the atresia is surgically corrected, the surgeon is often faced with the problem of restenosis. The rates of restenosis vary widely and range from 0 - 85% [5]. Many authors report on the use of postoperative stenting for variable periods [11].