SOURCE: Dept. of Otolaryngology, UTMB, Grand Rounds
DATE: March 6, 1991
RESIDENT PHYSICIAN: R. Paul Fulmer, M.D.
FACULTY: Karen H. Calhoun, M.D.
SERIES EDITOR: Francis B. Quinn, Jr., M.D.
to Grand Rounds Index|
"This material was prepared by resident physicians in partial fulfillment of
educational requirements established for the Postgraduate Training Program of
the UTMB Department of Otolaryngology/Head and Neck Surgery and was not intended
for clinical use in its present form. It was prepared for the purpose of stimulating
group discussion in a conference setting. No warranties, either express or implied,
are made with respect to its accuracy, completeness, or timeliness. The material
does not necessarily reflect the current or past opinions of members of the UTMB
faculty and should not be used for purposes of diagnosis or treatment without
consulting appropriate literature sources and informed professional opinion."
-incidence of choanal atresia is approx. 1 in 5000-7000 live births.
-female to male ratio is 2:1.
-90% of these atresias are bony, whereas the other 10% are membranous.
-associated congenital anomalies occur in association with choanal atresia
in about 50% of the patients. (ie. CHARGE).
-unilateral is more common than bilateral(2:1).
-when unilateral, right-sided occurs twice as often as left-sided.
-an incomplete atresia is termed a choanal stenosis.
- A. Four theories for the development of choanal atresia:
- 1. Persistence of a buccopharyngeal membrane from the foregut.
- 2. Persistence of the nasobuccal membrane of Hochstetter - most
commonly accepted theory.
- 3. The abnormal persistence or location of mesodermal adhesions in the
- 4. A misdirection of mesodermal flow secondary to local genetic
factors better explains the popular theory of persistent nasobuccal
- B. Normal Nasal Development and an explanation of the mesodermal flow
theory: Normal nasal development begins with the migration of the neural
crests cells from their origin in the dorsal neural folds, laterally
around the eye and transversing the frontal process. This begins about
the 4th week and the nasal architecture is completed by the 12th week.
During the 9th week, the neural crest cells migrate through a meshwork of
hyaluronic acid and collagen filaments to a preordained position within
the facial processes. Various genetic factors affect this migration. If
the flow of these cells is altered in their position or in their total
numbers, then the burrowing of the nasal pits may not occur as planned and
in turn the thinning and eventual rupture of the anterior primary choana
is altered. After this migration of neural crest cells, the primitive
mouth and nose begin to separate in a posterior direction with the
nasoseptal elements growing caudally while the lateral palatal processes
are growing medially and the tongue drops to the floor of the mouth. This
creates the boundaries of the atresia plate:
- 1. superiorly - the undersurface of the body of the sphenoid bones,
- 2. laterally - the medial pterygoid lamina,
- 3. medially - the vomer,
- 4. inferiorly - the horizontal portion of the palatal bone. This
growth of the palatal process and septum posteriorly can cause the
backward migration of a collection of mesoderm left by the original flow
defect. However the vomer's posterior growth stops at the posterior
margin of the septum, but the lateral portion of the mesenchymal mass can
continue to migrate. This causes the atresia plate to lie in a tangential
plane in the choana at birth. If a lesser amount migration occurs
posteriorly then a thin membranous plate is more likely seen. However, if
the migration is excessive then a plate of bone from 1 to 12 mm thick can
been seen. With this degree of plate formation, a funnel-shaped nasal
passage is created with the marked fullness in the lateral and superior
wall region. Therefore, this better explains the theory of a persistent
nasobuccal membrane causing the choanal atresia. Also due to the general
developmental abnormality of the nose with this anomaly, additional
changes are also seen:
- 1. an accentuated arch of the hard palate,
- 2. a sweeping inward of the lateral and posterior nasal walls,
- 3. a narrowing of the nasopharynx by the posterior and lateral
III. Clinical Presentation
- A. Bilateral choanal atresia
- 1. Causes complete nasal obstruction - immediate respiratory distress
and even potential death due to asphyxia (because newborns are obligate
nose breathers until approximately 4 to 6 weeks at which time mouth
breathing is learned).
- 2. The respiratory obstruction is cyclic - as the child falls asleep
the mouth closes and a progressive obstruction starting with stridor
followed by increased respiratory effort and cyanosis. Either the
observer opens the child's mouth or the child cries and the obstruction is
- 3. Initial feeding is often the alerting event - as the child starts
with inability to eat and breath at the same time, there is a progressive
obstruction of the airway and subsequent cyanosis and choking due to
aspiration of the milk. This can mimic a tracheoesophageal fistula.
- B. Unilateral choanal atresia
- 1. Rarely causes any acute respiratory distress.
- 2. Most common finding is a unilateral mucoid discharge.
- 3. Unilateral choanal atresia does not require any immediate surgical
- C. Associated congenital anomalies
- 1. CHARGE association - (C,coloboma; H, congenital heart disease; A,
atresia choanae; R, retarded growth and development; G, genital anomalies
in males; E, ear anomalies and deafness).
- a. 59% of patients with CHARGE Association have bilateral
choanal atresia. The rest have unilateral choanal atresia.
- b. therefore, when bilateral choanal atresia is diagnosed a
complete physical assessment by a pediatrician should be performed.
- 2. 75% of all patients found to have multiple congenital anomalies and
who have choanal atresia, have bilateral choanal atresia.
IV. Evaluation and Planning
- A. Physical Exam - Once the diagnosis of choanal atresia has been made
it can be confirmed initially on physical exam by:
- 1. failure to pass a # 6 to 8 French plastic catheter through the
nares into the pharynx. (a typical solid feeling will be encountered at
the level of the posterior choana approx. 3-3.5 cm from the alar rim).
- a. if however an obstruction is encountered at approx. 1-2 cm
from the alar rim, then this is most likely due to a traumatic deflection
of the nasal septum during delivery.
- b. if the nasal obstruction is due to mucosal swelling and
turbinate hypertrophy, then a catheter will pass into the pharynx and the
obstruction is just functional.
- 2. Passage of soft metal probes have been advocated for the same
reasons as above.
- 3. Placing wisps of cotton in front of the nares and watching for the
presence or absence of nasal movement of air.
- 4. Placing methylene blue in the nares and not visualizing it within
- B. Imaging Studies
- 1. Plain films and tomograms of the skull with radiopaque dye
instilled into the nasal cavities.
- 2. An axial noncontrast high resolution CT scan with thin sections
(2-5mm) has become the single radiographic study of choice. The CT scan
has proven invaluable in the accurate assessment of both the normal and
abnormal anatomy of the nasal cavity, posterior nasal choanae and
nasopharynx. The knowledge obtained from the CT scan is valuable in the
preoperative planning of the method and design of the repair.
- a. Slovis, et al. reviewed multiple CT scans of both normal
patients and patients with choanal atresia and found two parameters which
are useful in evaluating the abnormal anatomy of choanal atresia.
- i. choanal airspace measurement (normal) - the distance from the
lateral wall of the nasal cavity to the vomer bone. The mean choanal
airspace distance in the newborn was found to be 0.67 cm and it increased
0.027 cm / year until age 20y.o.
- ii. vomer bone width (normal) - the mean width was found to be 0.23 cm
in children 0-8 y.o. and only increased to 0.28 cm between 8 and 20 y.o.
- iii.choanal airspace measurement (atresia) - this measurement was absent
for patients with bony atresia and was one third of normal for patients
with membranous atresia.
- iv. vomer bone width (atresia) - were found to be almost three times the
normal group for patients with bony atresia with a mean width of 0.6cm.
The width was found to be only 0.3 cm for those with membranous atresia.
- v. The CT scan is also very useful for repeated consultation during the
procedure allowing the surgeon to determine where and how much of the
posterior hard palate need be removed to expose the atresia plates.
- vi. Likewise during the revision procedures, the CT scan can accurately
determine any residual posterior choanal stenosis and the extent of scar
- vii. CT scan also helps exclude most if not all of the other diseases
which could cause nasal obstruction of the newborn:
- a. generalized mucosal congestion of the newborn ("stuffy nose
- b. encephalocele,
- c.tumors including dermoids, gliomas, hamartomas, chordomas,
teratomas, and rhabdomyoscarcomas to name a few, iv. traumatic birth
deformity or dislocation of the nasal septum causing either partial or
complete nasal obstruction. This is the most common cause of partial or
complete nasal obstruction in the newborn!
V. Initial Management
- A. Airway - an oral airway of some sort must be implemented very early
on in the treatment of newborns with choanal atresia.
- 1. a typical anesthesia oral airway is often sufficient, however if
- 2. Orogastric tube - Hough pointed out that the obstructive seal
between the tongue and the palate in infants with bilateral choanal
atresia can be broken with the insertion of a large orogastric tube(No. 12
or 14 French). Once the seal is broken then it serves as an oral airway
as well as a conduit for feeding. This is used with only moderate success.
- 3. Intraoral nipple - a large nipple can be modified by having its
end cut off and then ties are attached to the nipple and placed around the
occiput. This type of airway is called a McGovern nipple and provides an
airway through which the baby can breath. A very small feeding tube can
then we passed either through another hole in the nipple or along side
the nipple for gavage feeding. This is the preferred method of
establishing an oral airway.
- 4. Tracheostomy - this is a controversial issue and many physicians
conclude that there is never a need for this drastic a step in the initial
management of infants with choanal atresia. However, Finkelhor et al.
recently reported a retrospective review of sixteen patients who had
CHARGE Association and they concluded these patients have a high
propensity of airway instability. They also reported that these
children's early repair of their choanal atresia is rarely successful,
primarily due to their abnormal anatomy of their nasopharynx and upper
aerodigestive tract. They also found that these patients tended to have
at least one cardiopulmonary arrest prior to their definitive procedure.
Therefore, they have proposed that children who have CHARGE Association
should have early tracheotomy to protect their brain from anoxic injury
and delay the repair of their choanal atresia until they are at lease 2
years of age. This is still a very controversial subject.
- B. Feeding - usually gavage 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'.
VI. Surgical Management
- A. Transnasal blind puncture - this is the first technique which was
described by Emmert in 1853. This technique should be avoided because of
the potently serious complications: CSF leaks, midbrain trauma, and
- B. Transnasal Approach (and with Endoscopes)
- 1. Technique:
- a. patient is placed under GETA
- b. self-retaining aural speculum is used to expose the nasal
cavity and the atresia plate,
- c. decongest the nose(ie. neo-synephrine nose drops)
- d. 0.5% lidocaine with 1:200,000 epi. is injected into the
mucosa overlying the bony atresia. (d.1). Benjamin and others have
advocated placing the Dott-Dingman self-retaining cleft palate gag at this
time to give excellent access to the pharynx and allows the surgeon to
monitor the perforation of the atresia plate with a 120 degree Storz
Hopkins telescope or a mirror.
- e. with the microscope (or 2.5-4.0 mm endoscopes) and otologic
instruments a mucosal incision is made and the mucosal flaps are elevated
and this exposes the posterior vomer and lateral pterygoid lamina,
- f. then using a diamond burr on a angled handpiece, the bony
atresia plate is perforated at the junction of the plate, hard palate, and
vomer (which is the thinnest section of the atresia). When performing the
endoscopic procedure described by Stankiewicz, the atresia plate is
perforated with a small suction tube and then the drill is used to widen
the opening. (f.1). the inferior turbinate can be either outfractured or
upfractured as necessary to increase the surgeons visualization.
- g. the remaining atresia plate is then removed, only preserving
the anterior mucosal flaps.
- h. an attic hook can be passed through the enlarging choana to
assess the proximity to the lateral pharyngeal walls.
- i. CAUTION - around the tors tubarius posteriorly and the
sphenopalatine vessels behind the middle turbinate.
- j. KEY - removing the posterior aspect of the septum is
accomplished by placing the burr into the nasopharynx through the choanea
and bringing it forward and medially against the vomer. (During the
endoscopic procedure described by Stankiewicz he uses the backbiting
forceps to remove the vomerine septum).
- k. newly created choana should be approximately the size of a
16-Fr van Buren sound. These should be placed into each nares
simultaneously to check the patency and choanal size.
- l. then a silastic stent should be placed into each nostril and
should rest just inside the nasal ala and should only protrude approx. 5
mm beyond the newly formed choanea. (These are left in place for 6-8
- 2. Advantages:
- a. This approach is faster, easier, and less problematic.
- b. Blood loss is minimal.
- c. Excellent for children of all ages when the atresia is thin
and there is no nasal deformities or anomalies.
- d. Pirsig reviewed more than 100 papers dealing with choanal
atresia and different operative approaches and he found that the
transnasal approach was successful in up to 80% of the cases. However
another review of the literature showed a 50-60% restenosis of patients
treated with the transnasal approach.
- e. Allows for earlier repair in properly selected patients and
may avoid restenosis. (as early as 24-48 hrs. from the time of diagnosis).
- f. The child can breast feed immediately post op.
- g. If no additional problems then the child can be discharged
on the 3rd or 4th post op day.
- 3. Disadvantages and Complications:
- a. A main disadvantage of this technique is the limited vision
the surgeon has via the nares, especially in the newborn if the endoscopes
are not used.
- b. Also the inability to adequately remove enough of the
posterior vomerine septal bone and prevent restenosis.
- c. Longer stenting time post op.
- d. The endoscopes are not binocular, so the surgeon's position
and anatomy have to be rechecked often.
- e. Can not be done safely and with good results on patients
with multiple nasal and nasopharyngeal anomalies.
- C. Transpalatal Approach
- 1. Technique:
- a. The patient is placed under GETA.
- b. The Dingman-Denhardt mouth gag with the infant tongue blade
should then be placed.
- c. The palate is injected with 0.5% lidocaine with 1:200,000
epinephrine in the area of the mucosal incision.
- d. Then a Owens type(U-shaped) mucosal incision is made
beginning just behind the maxillary tuberosity on one side and then
continued medial to the alveolar ridge up to the canine region and then
angled back to the nasopalatine foramen. A likewise incision is made on
the opposite side and the mucosal flap is elevated taking care not to
damage the greater palatine arteries.
- e. The mucosa of the nasopharynx and nose is elevated and
- f. Then the palatine bones posterior to the greater palatine
foramina, the atresia plates and the posterior vomer are carefully drilled
away using a diamond burr.
- g. Two 14 or 16 French catheters are passed simultaneously into
each nostril to check the patency of the newly created choanea.
- h. The preserved mucosa is then used to cover the superior and
inferior surfaces of the newly formed choanea and then sutured in place to
cover the bone.
- i. Then stents are placed and left in place for 4-6 weeks.
- j. Theogaraj et al., recommends leaving the oral airway in
place for 1-2 weeks post operatively until the child is able to breath
through the prosthesis.
- 2. Advantages:
- a. the surgeon has better visualization and preservation of
nasal mucosal flaps lining the newly produced choanea.
- b. these patients tend to require a shorter stenting period
post op(4 to 6 weeks).
- c. also there is a higher overall success rate with the
- d. Pirsing found that the transpalatal approach was successful
in up to 84% of the cases.
- 3. Disadvantages and Complications:
- a. the incisions, which are identical to those for a cleft
palate repair, may have a banding effect on maxillary growth due to scar
formation. (Therefore, most surgeons prefer to wait to use this approach
until some teeth are in occlusion - at approx.12-18 months).
- b. the stunting of palatal growth was documented by Freng to
have occurred in 52% of his patients studied with the transpalatal
approach. (particularly prevalent in those operated on early in life).
- c. Very few surgeons feel comfortable performing a transpalatal
approach on a newborn and will in turn prefer to place a McGovern nipple
until oral breathing is established. Also some surgeons will perform a
transnasal surgery as a prophylactic procedure and leave the transpalatal
surgery for the definitive procedure.
- d. Increased risk of intraoperative blood loss.
- e. Increased post op pain and discomfort.
- f. Also have a greater risk of developing palatal fistulas post
VII. Postoperative Care
- A. Stenting: There are multiple types and methods of stenting, but the
basic premise is to place either a hard or soft portex/silastic tube into
each nostril and secure them in place for a approximate period of 4-8
weeks, depending upon the author.
- 1. Theogaraj et al., advocates the use of a double barreled silicone
Elastomer tube which has a coiled wire incorporated within its walls to
- i. He then glues a Dacron-reinforced strap between the tubes
which will rest against the septum posteriorly.
- ii. Once the stents are brought to rest in the nose, then the
anterior ends are drawn through a silicone plate with precut holes and
then bonded in place with silicone adhesive.
- iii. The excess tubing anteriorly is cut off and these children
are left in their stents for 6-8 weeks.
- 2. Morgan DW and Bailey CM are proponents of using a Portex
endotracheal tube cut to the appropriate length and shape.
- i. The tube is folded in half and placed in the nose with the
open ends through the newly created choanea.
- ii. The bend in the stent is the opened on one side over the
- iii. The stent is secured in place by passing a nylon ligature
down the inside of each tube and around the back of the nasal septum, tied
over the columellar bridge of the stent.
- iv. The stent is removed after 6 weeks and the patient is
continued on nasal steroid drops for 2 weeks. The patient is examined
under general anesthesia 6 weeks later and any granulation tissue or
scaring is removed at that time.
- 3. Grundfast et al., has recently devised a even more creative way to
stent his patients with good success.
- i. Silastic tubing is used to make the stent. The size of
the tubing should be the largest diameter tubing that fits securely into
- ii. An oval shaped window is first cut with a scalpel into the
tube at a site equidistant from both ends. This window will serve as the
common open posterior portion of the two stents.
- iii. The tubing is then folded upon itself forming two parallel
hollow tubes with a silastic bridge at one end.
- iv. A double-armed pacemaker wire is then passed through the
medial (septal) wall of the stent on one side and brought out through the
posterior window. The wire should enter the stent approx. one cm from the
- v. The wire is then passed through the opposite posterior
window and out approx. one cm. from the opening on the opposite side at a
corresponding entry position of the medial wall.
- vi. The stent is then inserted into the nose via Robnels
attached to the two wire ends in the mouth and then brought out back
through the nose(just like a posterior pack).
- vii. The U-shaped Silastic tubing is now seeded in the
posterior on third of the nose within the newly created choanea.
- viii.To secure this in place, the surgeon makes a sublabial
incision and identifies the nasal spine.
- ix. The free ends of each wire are threaded on two separate
Keith needles and passed separately through the floor of the nose and into
the sublabial incision.
- x. After the position of the stent is verified with a mirror
or 90 degree telescope, the wires are tied securely anterior and inferior
to the bony anterior nasal spine. The incision is closed with 4-0 Vicryl.
- xi. Under general or local anesthesia depending upon the age
of the patient, the sublabial incision is reopened, the wire is cut and
the stent is grasped with a right angle and removed.
- xii. The author feels this is a very useful technique and the
child is not deformed by the stent for the 6-8 weeks or longer that may be
required. (Especially in school age patients who are having a unilateral
choanal atresia repaired and wish to return to school without being
- B. Wound Care:
- 1. The parents must be taught to maintain the stents with frequent
suction and a saline-moistened pipe cleaner or cotton applicator 3 to 6
times per day.
- 2. Antibiotics and decongestants are prescribed for any purulent
- 3. Many authors leave the children on prophylactic antibiotics
(ie.EES) while the stents are in place.
- C. Follow Up:
- 1. The patients are followed up every 2 weeks or more frequently if
needed while the stents are in place.
- 2. Then once the stents are removed, the patients are seen weekly for
the first 2-3 weeks to treat and granulation tissue and for suctioning.
Any dilation of choanea can then be done at the earliest indication of
- A. Membranous Choanal Atresia - most of these cases can be repaired via
a transnasal approach with good success rate with only one procedure.
- B. Unilateral Bony Choanal Atresia - These patients are usually not a
respiratory emergency. Therefore they can be followed closely and planned
to have the definitive repair at 5-6 yrs. of age if no other medical
problems preclude waiting. There is still controversy as to which
procedure to perform, but many of the recent papers encourage the use of
Endoscopic transnasal surgery for the definitive repair.
- C. Bilateral Bony Choanal Atresia - These patients are usually in
respiratory distress when you are asked to see them and require an oral
airway of some type(ie. McGovern nipple) and to begin on gavage feeding
while a CT scan is obtained to help establish a plan for surgery. There
are still two camps divided on this issue of which is the best definitive
procedure for these patients. The CT scan often helps tremendously in the
decision of which type of surgery is indicated and when to proceed.
- 1. The transnasal proponents feel that when there is only a minimal
bony atresia plate and not much lateral bony overgrowth, then they can
proceed with the transnasal approach as the definitive procedure. These
doctors also feel that the transnasal approach can be done initially in
the first few days of life with minimal morbidity or mortality as a
prophylactic measure knowing that in 2-3 months the definitive procedure
will need to be transpalatal.
- 2. The transpalatal proponents believe that this is the most reliable
and successful method to repair bilateral bony choanal atresia with one
operation. Therefore, they recommend an oral airway for 1 to 3 months or
until the child is mature enough to undergo surgery. (The exact weight or
age of the child preop is not clearly defined in the literature. Some
authors operate at one month and others wait until 3 months of age).
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