Choanal Atresia

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Choanal Atresia : 

Choanal Atresia

Case Presentation : 

Case Presentation You are asked to see a neonate born at 36 weeks for intermittent cyanosis. Birth history: born to G4P3 mother, by c-section for placenta previa. Apgars are 8, 9. The neonate then desaturates at 7 minutes of life. She is bag ventilated and recovers. History: No birth defects in family. Uneventful pregnancy. No exposures.

Exam : 

Exam Mouth breathing, retracting slightly at neck Shortened palpebral fissures with no visible globe Left cleft nare Ankyloglossus Low set ears Normal fingers RRR no murmurs Abdomen soft, no organomegaly Cannot pass catheter or FFO scope either nare

Nasopharyngeal obstruction DDx : 

Nasopharyngeal obstruction DDx Vascular - hemangioma Infectious - Chlamydia Traumatic- septal hematoma, dislocated nasal septum Autoimmune – sarcoid, RA, churg-strauss Metabolic – cystic fibrosis Iatrogenic/idiopathic – septal hematoma, dislocated nasal septum, kartageners Neoplasia – hamartoma, nasopharyngeal mass hairy polyp, teratoma, chordoma, rhabdomyosarcoma, angiofibroma, hemangiopericytoma, scc Congenital - Choanal stenosis/atresia, Piriform aperture stenosis, Nasal glioma, Encephalocele, Meningocele, dermoid, Micrognathia, Macroglossia, Treacher collins, Down’s syndrome, Cystic Hygroma, Lingual thyroid, incisive canal cysts, nasolacrimal duct cyst, dentigerous cysts

Nasal endoscopy : 

Nasal endoscopy Right Left

CT scan : 

CT scan Her scan Different Pathology

CT scan evaluation : 

CT scan evaluation Choanal airspace measurement: mean normal is 0.67cm. Mixed atresia is 1/3 of normal, bony atresia measures 0. Vomer width – Mean 0.23cm, bony atresia mean 0.6cm, membranous atresia 0.3 cm. Slovis TL et al. Choanal Atresia: Precise CT Evaluation. Radiology. 1985;155:345-348.

Epidemiology : 

Epidemiology 1:5000-1:8000 live births 50% with other anomalies 65-75% unilateral. 75% of bilateral cases have other anomalies. Polydactyly, nasal-auricular and palatal deformities, crouzon’s, craniosynostosis, microencephaly, meningocele, meningoencephalocele, facial asymmetry, hypoplasia of orbit and midface, hypertelorism, cleft palate 29% bony, 71% mixed (brown et al)

Typical presentation : 

Typical presentation Bilateral – cyclic cyanosis relieved by crying Unilateral – chronic nasal obstruction, thick tenatious mucous

anatomy : 

anatomy Bounderies of the atresia plate: Superior: sphenoid Lateral: medial pterygoid lamina Medial: vomer Inferior: horizontal portion of the palatal bone

Anatomy : 

Anatomy Narrow nasal cavity lateral obstruction by lat pterygoid plate, Vomer thickening, membranous obstruction Medial pterygoid plate and posterior vomer are expanded by endochondral bone formation and fibroepithelial membrane that obstructs the choanae

Further work up : 

Further work up As always, AIRWAY first Genetics evaluation Cardiology (EKG, Echo) Opthalmology evaluation Hearing UA (kidney)

Management : 

Management Unilateral delayed to allow the patient to grow, and reduce risk of restenosis Bilateral – creating oral airway- Mcgovern nipple with enlarged hole or two side holes, surgical correction vs tracheostomy Stimulate infant to cry, intubate, bag ventilate if obstructing in an emergency Genetics consult, work up for other anomalies

Surgical Approaches : 

Surgical Approaches Transnasal Transpalatal Transseptal

Transnasal/transseptal : 

Transnasal/transseptal Most common repair strategy now that endoscopes are used Multiple techniques – all use either mucosal flaps or stenting to prevent restenosis

Transnasal : 

Transnasal

Transnasal pros/cons : 

Transnasal pros/cons Punching through the atretic plate is essentially blind process – important to go inferomedial to avoid sphenopalatine artery, and drill parallel to palate to avoid entering clivus, sphenoid Risks include all those of FESS, but anatomy is abnormal and less predictable Does not impair development of dental arches Uses equipment/techniques similar to FESS

Transnasal/transseptal : 

Transnasal/transseptal Cedin AC, Fujita R, Cruz OL: Endoscopic transeptal surgery for choanal atresia with a stentless folded-over-flap technique. Otolaryngol Head Neck Surg 2006 Nov; 135(5): 693-8

Transpalatal : 

Transpalatal Tewfik et al., 2007 Include greater palatine for blood supply to flap Subperiosteal elevation to leading edge of hard palate Cutting burr used to drill the posterior vomer and atretic plate. Stents placed Incision made 5 mm from dental arch

Transpalatal drawback : 

Transpalatal drawback 52% incidence of dental malocclusion resulting from narrowed maxillary dental arches in patients younger than 5 years Palatal flap necrosis Palatal fistula Persistent submucous tunnel Restenosis Upside: success rate of over 80% is comparable to all other approaches

Syndromes : 

Syndromes CHARGE Treacher Collins Crouzon’s

CHARGE syndrome : 

CHARGE syndrome Coloboma and/or CNS abnormalities Heart abnormality Atresia choanae Retardation of growth Genital defects (males) Ear anomalies/deafness Mutations on the CHD7 gene (located on Chromosome 8) were found in 10 of 17 patients in a study conducted in the Netherlands (Vissers, et al., 2004). A study in the US of 110 individuals with CHARGE syndrome showed that 60% of those tested had a mutation on the CHD7 gene (Lalani et al., 2006).

CHARGE : 

CHARGE The percentages of the different anomalies in CHARGE association are as follows: Coloboma - 80% Heart defect - 58% Atresia of choanae - 100% Mental retardation - 94% Growth deficiency - 87% Genital hypoplasia in males - 75% Ear anomalies - 88%

CHARGE : 

CHARGE Other features: kidney anomalies, OCD Palmar crease, esophageal atresia, tracheoesophageal fistula, scoliosis, chronic middle ear problems, clefts

Treacher Collins : 

Treacher Collins Malar hypoplasia Colobomas Medial 2/3 lash without lashes Retrusive chin Class 2 malocclusion External ear anomalies SNHL Rarely choanal atresia

Which of the following are true of Treacher collins syndrome : 

Which of the following are true of Treacher collins syndrome A. Autosomal Recessive B. Mutation in the TCOF gene, coding treacle C. Abnormal third branchial arch development D. External ear anomolies are present but there is no hearing loss E. Surgical correction typically at 7 years of age.

Embryogenesis : 

Embryogenesis Nasal placodes invaginate to form nasal pits 3-4 weeks of gestation These enlarge and burrow into underlying mesoderm, forming nasal pouches Floor between nasal and buccal cavity thins to form nasobuccal membrane Membrane ruptures at 6 weeks gestation Choanal atresia – cause unknown, thought to be due either to persistence of nasobuccal membrane, buccopharngeal membrane, or due to errors in mesoderm migration

Epidemiology : 

Epidemiology 1:5000-1:8000 live births 50% with other anomalies 65-75% unilateral. 75% of bilateral cases have other anomalies Polydactyly, nasal-auricular and palatal deformities, crouzon’s, craniosynostosis, microencephaly, meningocele, meningoencephalocele, facial asymmetry, hypoplasia of orbt and midface, hypertelorism, cleft palate

Embryogenesis : 

Embryogenesis

Hemifacial microsomia : 

Hemifacial microsomia Orbit Mandible Ear Facial nerve Soft tissue Defect of first and second branchial arches - ? Vascular insult

Treacher Collins : 

Treacher Collins Malar hypoplasia Colobomas Medial 2/3 lash without lashes Retrusive chin Class 2 malocclusion External ear anomalies SNHL