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Choanal Atresia - Corrective Surgery Using Hegar's Dilators
Authors: Vikas Sinha*, Niral Modi**, Viral A. Chhaya***, Vishal
Parmar****, Parin Patel*****, Swapna Patil*****, Prashanth
C.D.****, Jay Dave****, Kapil****, Nikhil Gupta****, Deepanshu
Gurnani**** , Dilavar A. Barot**, Hiten Maniyar**
*Dean, Professor E.N.T., **Assistant Professor, ***Professor and
Head, ****Junior Resident, *****Senior Resident
Institution: Department of Otolaryngology and Head and Neck
Surgery, M.P.Shah Medical College, Jamnagar (Gujarat), India
Corresponding Author: Dr. Vikas Sinha Dean, Prof E.N.T. M.P.Shah
Medical College Jamnagar (Gujarat), India E mail
[email protected]
Abstract
Background and objective: Bilateral choanal atresia is a medical
emergency and surgery is the only means of treatment for this
condition. Hegars dilator was used in all cases to break the bony
and membranous atretic plate. Material and Method: Seven cases of
choanal atresia were studied. Six cases were 1-5 days old with
bilateral complete choanal atresia. They all required immediate
surgery as they had repeated attacks and cycles of cyanosis. Four
neonates were associated with the CHARGE syndrome. All of the cases
were done under general anesthesia. Hegars dilators were used in
all cases and nasal stents were placed in all cases. Results:
Although complete nasal patency was achieved by surgery, in four
cases, neonates could not survive due to the CHARGE syndrome. The
mortality was unrelated to the surgery. The two cases which were
not associated with CHARGE syndrome had a good postoperative
recovery. One case was 14 years old with a unilateral, complete
bony and membranous choanal atresia. This patient required surgery
due to continuous nasal discharge. Conclusion: Hagers dilators are
a safe and simple method of surgery for choanal atresia. Nasal
stenting is mandatory to prevent restenosis
mailto:[email protected]
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Introduction
In 1775, Roeder first described Choanal atresia and in 1829 the
entity was further defined by Otto.1 The derivation of the word
"Choana" is Greek from the word Xovan, meaning funnel. The term "
Posterior Choana" would literally mean a posterior funnel. However,
its usage in modern day medicine is somewhat of a misnomer, since
its meaning is the posterior aperture of the nasal cavity. Choanal
atresia is one of the more commonly observed congenital
abnormalities of the nose.2 In the neonate it is life threatening,
since neonates are obligate nasal breathers for the first six weeks
of life, and will enter a state of severe respiratory distress
after the crying from childbirth has ceased. The incidence of this
abnormality is between one in 5000 to one in 8000 births.3,4
Embryology: The embryonic origin of choanal atesia is thought to
be a persistent bucco-pharyngeal or naso-buccal membrane.3 During
embryologic development, the nasal cavities form from nasal
placodes on the lateral surface of the head. These placodes sink
into the mesoderm and form the nostrils and the anterior nasal
cavity. This process is influenced by the lateral palatal shelves
which fuse in an anterior-to-posterior direction and form much of
the hard and soft palate. The nasal cavity is influenced and formed
as the lateral palatal processes fuse in a posterior direction.
The membrane which separates the oral and nasal cavities thins
and is finally reabsorbed. The reabsorbtion of this membrane forms
the posterior choana.5 If the membrane fails to reabsorb then a
choanal atresia will be present.6 Factors which may cause an
atretic choana are a medial outgrowth of the vertical or horizontal
process of the palatal bone and persistent mesenchyme with
misdirection of developmental flow.7
Pathophysiology: In the neonate, the epiglottis is more
superiorly positioned then the adult. When an infant swallows, the
larynx rises and the epiglottis enters the nasopharynx and locks
between the soft palate and the sides of the nasopharynx.
During inspiration, a neonate sucks the tongue and a vacuum is
created in the oropharynx. This helps to move the soft tissues of
the floor of the mouth up and back towards the soft palate. During
expiration, the pressure in the airway causes the soft palate to
push forward against the soft tissues and tongue in the mouth, also
obstructing the oral airway.8
The oral airway is blocked with quiet respiration. The infant is
an obligate nasal breather, and only breaths through his mouth
during crying. Reduction in the diameter of the nasal airway by one
third can increase nasal airway resistance by 81 times and result
in respiratory distress in neonates. Nasal stenosis has the same
effect and if both nasal cavities have a complete absence of a
patent airway, a medical emergency exists. The infant will become
cyanotic, which is broken by crying or gasping when the mouth is
open widely. In a resting state, the child has severe retractions,
struggles to breath with the rapid development of cyanosis. Crying
instantly relieves the airway obstruction and the cyanosis
disappears. If the crying stops, the mouth closes and the cycle
repeats itself. Rarely, an infant with bilateral choanal atresia
develops the ability to mouth breath.9 If this happens the medical
emergency subsides but the child still requires treatment.
Forty-seven percent of patients with choanal atresia without
chromosome anomalities have the CHARGE Syndrome. The CHARGE
Syndrome is comprised of Coloboma of the Iris with or without
microphthalmia, Heart defects (i.e., atrial septal defects),
choanal atresia (Atresia of the choana), Retarded growth and
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abnormalities of the Genitourinary system (i.e., cryptorchidism,
microphallus, hydronephrosis) and Ear abnormalities with associated
deafness.
It is imperative to diagnosis choanal atresia immediately after
birth. If any doubt regarding the patency of a neonate's airway
exists in the recovery room, a catheter should be passed through
each nostril and into the child's oral cavity. The passage of the
catheter down each nostril should be performed on every newborn in
the the recovery room.
To confirm the diagnosis of a suspected choanal atresia, a
lateral x-ray is taken after radiopaque dye is placed into the
child's nasal cavity. If an atresia is demonstrated, a Computerized
Tomographic scan is obtained to further delineate the
characteristics of the choanal atresia. For the best results, the
nasal cavity should be suctioned, immediately before the test to
remove any nasal secretions.
The benefits of obtaining a CT Scan are as follows:
1. Confirm the diagnosis and if it is on one or both sides. 2.
Determine the anatomy of the atretic area, including the width of
the Vomer bone and the medial displacement of the sides of the
lateral wall of the nose. 3. To measure the thickness of the
atretic plate and the presence and thickness of a bony plate. 4. To
determine if any other sites of obstruction or abnormalities exist
in the nasal, nasopharyngeal or sinus cavities.
Methods
This is the prospective study of 7 cases of choanal atresia. The
6 cases had bilateral bony choanal atresia and all were of 1-5 days
old. One case was an adult, 14 year old girl, having unilateral
bony and membranous choanal atresia. All the surgery was done by
the first author. Each patient was investigated in detail with
respect to sex, age of presentation, type and site of atresia, and
associated other congenital anomalies. The diagnosis was made
clinically by the inability to pass a small suction catheter
through the nares and confirmed by CT scanning and nasal endoscopy.
The immediate management of a child with respiratory distress was
the insertion of an oral airway.
All patients underwent surgical repair of choanal atresia
through a transnasal technique. A curved Hegars dilator from
obstetrics and gynecology was used to perforate the atretic plate,
transnasally, in bony and membranous atresia and subsequently to
dilate the opening. A 4 mm, 0 degree nasal endoscope was used for
visualization before and after the dilatation. All patients were
stented using portex endotracheal tubes. They were inserted by
using the procedure of “Vikas Sinha Stenting” for a period of 7 to
15 days depending on the tolerability of the patient. All patients
were given postoperative prophylactic antibiotics.
Surgical Technique: Surgery was performed under general
anesthesia with a cuffed endotracheal tube to prevent the
aspiration of blood during surgery. Hegars dilators were used to
perforate the obstructing plate ( Fig 1-a and Fig 1-b). Hegars
dilators have the ideal curvature to follow the sloping contour of
the nasal floor. The smallest size of Hegars dilator was used to
perforate the atreric plate (Fig 2-a). The atretic plate is almost
always thinnest and weakest at the junction of the floor and the
posterior end of the septum and can be easily perforated. The
dilator is passed along the floor of the nose, staying against the
septum to avoid penetrating the basal sphenoid. It must be
remembered that the floor of the nose of the infant is not straight
but curved, paralleling the curve of the hard palate. The index
finger of the left hand was placed at
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the nasopharynx (Fig 2-b) against the nasopharyngeal side of the
atretic plate mainly to safeguard accidental sudden perforation and
prevent the accidental hitting or damage of the base of the skull.
When the atretic plate was touched, the dilator was carefully
forced through it with gentle uniform pressure and screwing
movement till the atretic plate was perforated. The atretic plate
is serially punctured and dilated using increasing sizes of Hegars
dilator (Fig 2-c). Both sides were dilated, serially, to prevent
shifting of the septum. The maximum size of the dilator used for
the dilation approximates a size that is slightly smaller than the
child's nostril. A similar procedure was repeated on the other
side. Surprisingly, there is little bleeding during the entire
surgery.
12 Year Old Indian Female With Left Choanal Atresia
Enlarged Pictures at End of Document
Figure 1-A: Pre operative bony atretic plate
Figure 1-B: Pre operative bony atretic plate
Figure 2-A: Insertion of the smallest size Hager's dilator
Figure 2-B: The surgeon's finger placed in the nasophaynx as a
safe guard
Figure 2-C: Dilatation with larger sized Hager's dilators
Stenting procedure: Vikas Sinha stenting - A noncuffed portex
endotracheal tube was used for stenting. The size of the tube
should be approximately the size of the last Hegars dilator used.
The tube is folded exactly equal from the midpoint thus making two
exactly equal lengths. The posterior fenestration (outer curved
side) of the tube at the midpoint was created with a No. 11 blade
(Fig 2-d) for the air to pass from the nose to the nasopharynx
while the anterior part of the tube (inner curved end) remains in
continuity2 (Fig 2-e). Smaller vents or holes were made in a
different site and axis for the drainage of nasal secretions. Two
red rubber catheters are passed from both nasal cavities to be
taken out from the oral cavity (Fig 2-f). The two ends of the newly
created stent were tied with a red rubber catheter and pulled
retrograde from the nasal cavity. Both rubber catheters are pulled
together and simultaneously (Fig 2-g) so
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that posterior fenestration lies exactly in the midline at the
nasopharynx. Care should be taken so as not to twist the stent. An
equal length of the two tubes outside of the nose will ensure that
the posterior fenestration is in midline and in the nasopharynx. A
small red rubber catheter is passed through the stent to prevent
blockage from a blood clot (Fig 2-h). The tube is secured at the
nostril with silk sutures (Fig 2-i) taking care not to damage the
columella by placing a small gauze piece at the columella. The
continual friction of silk suture against the columella causes
pressure necrosis on the columella. The excess length of tube is
cut. All the postoperative neonates were kept in the neonatal
intensive care unit for regular suction of the nasal passage for
one week.
Figure 2-D: Creation of fenestra in endotracheal tube
Figure 2-E: Endotracheal stent showing vent at posterior wall of
endotracheal tube for air to pass through. The anterior wall in
continuity. The small vents at different sides of tube for nasal
secretion drainage
Figure 2-F: Red rubber catheters passed from nose to
oropharynx
Figure 2-G: The red rubber catheters are attached to the stent,
so the stent can be position in the choana when they are pulled
through nose
Figure 2-H: The two ends of stent are delivered through nose,
centering the mid-portion at choana for respiration
Figure 2-I: The stent is sutured with silk sutures
Enlarged Pictures at End of Document
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Surgical Technique: View YouTube Video:
https://youtu.be/0NOLGTskRuA
View Flash Presentation:
http://www.waent.org/archives/2011/Vol4-2/20110609-choanal-atresia/choanal-atresia-manuscript.htm
Results
All the cases had established air passage completely on the
operation table. This was the criteria used for the successful
operation. Four cases of neonates were associated with CHARGE
syndrome. They all died within 2-4 days due to CHARGE syndrome
unrelated to surgery. Two children, who were otherwise normal,
survived this postoperative period and stenting was continued for 4
weeks and afterword it was removed. One adult patient had the
stenting continued for 3 weeks but postoperative columella necrosis
developed (Fig 3-a) which forced us to remove the stent. The
columellar skin was sutured with primary silk sutures (Fig 3-b) and
healing was excellent (Fig 3-c) due to very good blood supply of
this region. The nasal balloon catheter was used (Fig 4-a) for a
further 2 weeks to prevent restenosis (Fig 4-b). Nasal endoscopy
was done every 2nd or 3rd day to ensure proper positioning of the
nasal balloon (Fig 4-c). The balloon was removed in-between to
visualize any possible restenosis. The Karrison bone punch was used
under direct vision of the 0 degree 4 mm nasal endoscope to nibble
any bony growth. Saline nasal drops were used as needed to prevent
nasal crusting. Nasal endoscopy showed a wide nasal cavity at the
choanal (Fig 5-a). CT scan confirmed a successful surgery with an
absence of choanal atresia (Fig 5-b).
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Figure 3-A: Columellar necrosis Figure 3-B: Fine silk sutures at
columella
Figure 3-C: Excellent healing and final appearance of the
columella
Figure 4-A: Anterior nasal balloon catheter
Figure 4-B: Anterior nasal balloon catheter placed into the
naries
Figure 4-C: The balloon portion of anterior nasal balloon
catheter snuggly fitting the choana
Enlarged Pictures at End of Document
Figure 5-A: Postoperative view of the patient's wide choana
Figure 5-B: Six week post operative CT Scan showing a wide nasal
airway
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Discussion
Roederer first described choanal atresia in 1755 and Emmerth
first performed a transnasal operative repair. He used a curved
trocar to perforate the membranous atretic membrane. 11,12
There are a number of methods to diagnosis choanal atresia on
physical examination: A laryngeal mirror can be placed under the
nostril to test for fogging, failed attempts to pass a catheter
through the nose, or the absence of movement of a wisp of cotton
placed in front of the nostril. The time-tested method for
diagnosis is choanography where contrast material is placed in the
infant's nostril and a lateral x-ray is obtained. If this test is
positive, a CT scan should be performed, which will give an
accurate measurement of the atresia's thickness along with its
composition (membranous or bony).
There are five different surgical approaches that have been
described for surgical treatment of choanal atresia: (1)
trans-nasal; (2) trans-palatal; (3) trans-septal; (4) trans-antral
and (5) sublabial-transnasal.13,14 The two most popular techniques
that are used in newborn infants with choanal atresia are
trans-palatal and trans-nasal approaches. With the advent of the
endoscope and powered instruments, the transnasal approach becomes
more popular. It provides direct and excellent visualization of the
nasal cavity and choana. Hegars dilator was used in all our
patients. The dilator's curve conforms to the natural curve of the
palate. It is also blunt so there is less of a chance of damaging
surrounding structures. We determined the size of the stent by the
size of the last number of Hegar's dilator used for dilatation. The
Hegars' dilators were also used by Shama, et al., in a large series
of 14 patients with choanal atresia.15 There is some controversy
regarding the use of a stent. Because a stent may cause discomfort,
localized infection and ulceration, along with circumferential scar
tissue and injury to surrounding normal tissue. A properly sized
stent left in the nasal cavity maintains a circumferential
haemostatic pressure.2 Once removed may cause restenosis.
Indwelling nasal stents are difficult to manage and may migrate or
break.11 However most surgeons are using stent in the
post-operative period.16 The overall failure rate of surgery using
stents is about 30%.17 Tracheostomy has little place in the
management of airway problems caused by choanal atresia.
Endotracheal intubation is contraindicated unless the infant's
condition is so poor orS there is an unrelated airway
obstruction.18
Conclusion
The surgery for choanal atresia should be undertaken by the
E.N.T. surgeon as soon as the diagnosis is made by neonatologists
or pediatricians. The Hegars dilator is a very safe method to
perforate the atretic plate whether bony or membranous. The finger
on the surgeon's other hand is inserted into the nasopharynx to
prevent any damage to the base of the skull in case of accidental
sudden perforation of the atretic plate. Controlled pressure of the
Hegars dilator using a twisting movement is the key for the
successful controlled perforation of the atretic plate. Stenting
with either an endotracheal tube (“Vikas Sinha Stenting”) or
balloon is mandatory to prevent restenosis.
References
1. Cinnamond MJ. Congenital anomalies of nose. Scottbrown
Otolaryngology Pediatrics, 5th ed. London. Butterworth & Co.
Ltd 1987 pp 220-222.
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2. Sinha V. et al , Choanal atresia: surgery by puncture,
dilatation and stenting, J rhinol 13 (2) 2006. View Manuscript
3. Stankiewicz JA. The endoscopic repair of choanal atresia.
Otolaryngol Head Neck Surg. 1990 Dec;103(6):931-7. View
Abstract
4. Schwartz ML, Savetsky L. Choanal atresia: clinical features,
surgical approach, and long-term follow-up. Laryngoscope. 1986
Dec;96(12):1335-9. View Abstract
5. Hagerman KE, Toremalm NG, The management of bilateral choanal
atresia, J Laryngol Otol 1968 82:913-920.
6. Tewfik TL. Choanal atresia. emedicine. eMedicine. Drugs,
Diseases and Procedures. . 2011 p1. View Manuscript
7. Tewfik TL, Der Kaloustian VM. Choanal atresia. Rhinogram
demonstrating blockage of radiopaque dye at posterior choana.
Choanal atresia, Workup. eMedicine. Drugs, Diseases and Procedures.
2011 p4-11. View Manuscript
8. Winter LK. Congenital Choanal Atresia: Anatomic,
Physiological, and Therapeutic Aspects, Especially the Endonasal
Approach Under Endoscopic Vision. Arch Otolaryngol 1978
Feb;104(2):72-78. View Abstract
9. Fearon B, Dickson J. Bilateral choanal atresia in the new
born. The laryngoscope 1968 Sep;78(9):1487-1499. View Abstract
10. Hengerer AS, Strome M. Choanal atresia: a new embryologic
theory and its influence on surgical management. Laryngoscope. 1982
Aug;92(8 Pt 1):913-21. View Abstract
11. Emmert C. In: Lehrbuch der Chirugie Dann. Stuttgart: 1854.
p. 535-8.
12. Flake GC, Ferguson CF. Congenital choanal atresia in infants
and children. Ann Otol Rhinol Laryngol 1964 73:458-73
13. Freng A. Growth in width of the dental arches after partial
extirpation of the mid-palatal suture in man. Scand J Plast
Reconstr Surg. 1978 12:267-72.
14. Friedman NR, Mitchell RB, Bailey CM, Albert DM, Leighton SE.
Management and outcome of choanal atresia correction. Int J Pediatr
Otorhinolaryngol. 2000 Jan 30;52(1):45-51. View Abstract
15. Sharma RK, Lee CA, Gunasekaran S, Knight LC, Bielby M.
Stenting for bilateral congenital choanal atresia--a new technique.
Int J Pediatr Otorhinolaryngol. 2006 May;70(5):869-74. Epub 2005
Nov 15. View Abstract
16. Schoem SR. Transnasal endoscopic repair of choanal atresia:
why stent? Otolaryngol Head Neck Surg. 2004 Oct;131(4):362-6. View
Abstract
http://ksrhino.or.kr/upload/journal/0192006023.pdfhttp://ksrhino.or.kr/upload/journal/0192006023.pdfhttp://www.ncbi.nlm.nih.gov/pubmed/2126127http://www.ncbi.nlm.nih.gov/pubmed/3784736http://emedicine.medscape.com/article/872409-workuphttp://emedicine.medscape.com/article/872409-workuphttp://emedicine.medscape.com/article/872409-workuphttp://archotol.jamanetwork.com/article.aspx?articleid=607121http://onlinelibrary.wiley.com/doi/10.1288/00005537-196809000-00005/abstracthttp://www.ncbi.nlm.nih.gov/pubmed/7098739http://www.ncbi.nlm.nih.gov/pubmed/10699239http://www.ncbi.nlm.nih.gov/pubmed/16293318http://www.ncbi.nlm.nih.gov/pubmed/16293318http://www.ncbi.nlm.nih.gov/pubmed/15467600
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17. Richardson MA, Osguthorpe JD. Surgical management of choanal
atresia. Laryngoscope. 1988 Sep;98(9):915-8. View Abstract
18. Sinha V, Sridhar M, Sinha S. Bilateral choanal atresia in
the new born. Pediatric clinic of India. 1997 32(4):1-5
Figure 1A
http://www.ncbi.nlm.nih.gov/pubmed/3412088
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Figure 1B
Figure 2A
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Figure 2B
Figure 2C
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Figure 2D
Figure 2E
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Figure 2F
Figure 2G
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Figure 2H
Figure 2I
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Figure 3A
Figure 3B
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2011 Volume 4(2)
Figure 3C
Figure 4A
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Figure 4B
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Figure 4C
Figure 5A
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Figure 5B