Keywords
choanal atresia - nasal obstruction - endoscopy - early diagnosis
Palavras-chave
atresia das coanas - obstrução nasal - endoscopia - diagnóstico precoce
Introduction
Choanal atresia (CA) can be defined as a failure to develop the communication between
the nasal cavity and nasopharynx[1]. The incidence is 1:5.000-8.000 births, with girls being more affected than males
by a ratio of 2:1, unilateral defects are more common than bilateral[2]
[3]. It can occur as a board-membranous bone (70%), bone (20%) or membranous (10%).
Diagnosis depends on high degree of suspicion, nasal endoscopy and CT of the paranasal
sinuses, the treatment is surgical.
Discussion
Choanal atresia may present as an isolated malformation or in 20% to 50% of cases,
part of a group of congenital malformations, such as coloboma, heart malformation,
mental retardation and growth, genital anomalies and ear or deafness[4]. Thus, a complete physical examination should be done by the pediatrician and otolaryngologist
to identify the possibility of the presence of these anomalies. Some theories have
been proposed to explain the embryological origin of this clinical entity. Among the
most accepted, four stand out: 1) persistence of oral-pharyngeal membrane, 2) failure
to break the physiological oronasal membrane of Hochstetter, 3) adherence of abnormal
mesodermal tissue located in the nasal choana and 4) medial growth of vertical and
horizontal processes palatine bone[5]
[6].
Diagnosis depends on high degree of suspicion. The CA evolves with bilateral nasal
obstruction, stridor, cyanosis cyclic (improving with newborn's cry), but that can
lead to respiratory failure with immediate risk of death by suffocation, as the newborns
are obligatory nasal breathers until about 3 weeks of life. Therefore, it is a medical
emergency, requiring maintenance of the airway by oral intubation, tracheostomy tube
or use of the McGovern nipple, so as to stabilize the patient and schedule the definitive surgical method.
Unilateral atresia may go unnoticed for years and present with Late rhinorrhea and
unilateral nasal congestion, some patients, however, may remain mildly[7].
Ancillary tests such as CT of the paranasal sinuses and nasal endoscopy are essential
in diagnosis and therapeutic plan - the extent, location and distinctness of atresias
bone, membrane, and mixed[8]. It also serves to make differential diagnosis with other diseases, such as gliomas,
hamartomas, chordomas, rhabdomyosarcoma, encephaloceles, enlarged adenoid vegetations,
septal deformities, among others.
Initial treatment consists of maintaining the airway, if necessary, until the definitive
surgical correction, which should restore nasal airflow, preventing damage to the
facial growth using a safe and fast. Currently there are several techniques: microscopic
and endoscopic transnasal, transpalatal, transseptal, and dilations transantral intranasal[1]
[7]
[9]
[10]. The transnasal endoscopic technique is being increasingly used for surgical correction
of choanal atresia by offering a good view of the area, is less traumatic, have lower
complication rates and provide a faster recovery after surgery[11], so we chose this technique in our case.
Conclusion
Bilateral choanal imperforation has its early diagnosed because of symptoms more exuberant
and high degree of suspicion on the part of pediatric neonatologists. It is a disease
that endangers the child's life, and in most cases corrected in the first weeks. However,
in rare cases it can be found during the investigation of adults with bilateral nasal
obstruction and rhinorrhea, as reported in the case.
