posterior choanal atresia

I

THE AMERICAN JOURNAL

OF ROENTGENOLOGYRADIUM THERAPY AND

NUCLEAR MEDICINE

VOL. 112 MAY, i�7i No. I

POSTERIOR CHOANAL ATRESIA*

By HUGH J. WILLIAMS, M.D.ST. PAUL, MINNESOTA

T HERE is scant reference to posteriorchoanal atresia in the roentgenologic

literature, and a recent review of the 2

major radiologic journals published in this

country yielded no articles on this subject

since that of Whitehouse and Holt in1952.12

The purpose of this communication is

twofold. The first is to review the clinicalfeatures in 19 cases of this uncommonanomaly, and to emphasize the importance

of considering the bilateral form of this

disease in the differential diagnosis ofsevere respiratory distress in the newborn.The second purpose is to propose a clinicalclassification of bilateral choanal atresia

which the author feels is more meaningful

than the hitherto traditional anatomicclassification.

Failure to appreciate that bilateral

choanal atresia often presents as an emer-gency in the newborn period can be disas-

trous and result in tragic death fromasphyxia. While the initial diagnosis of

bilateral choanal atresia is usually sus-

pected and confirmed by the obstetrician orpediatrician, occasionally the radiologist

may be in a position to suggest the possi-

bility of this diagnosis. In other suspected

*From the children’s Hospital, Inc., St. Paul, Minnesota.

cases he can readily confirm the diagnosisroen tgenographicallv.

Schwartz and Isaacs1#{176} found that the

earliest published description of this con-

dition was by R#{246}derer in Gottingen, Ger-manv, around 1755. The first corrective

surgery was performed in 1851 by Emmert

who punctured the obstruction with a

trocar.2

ETIOLOGY AND INCIDENCE

Most embryologists believe that pos-

terior choanal atresia results from a failureof rupture between the 35th and 38th day

of fetal life of the partition which separates

the bucconasal or buccopharyngeal mem-branes. The resultant choanal atresia may

be unilateral or bilateral, bony or mem-

branous, complete or incomplete. In over

90 per cent of cases the obstruction is bony,while in the remainder it is membranous.9The bony type of atresia is commonly

located 1-2 mm. anterior to the posterioredge of the hard palate, and the osseousseptum varies in thickness from i to JO

mm. In the membranous form of choanalatresia the obstruction usually occurs fur-

ther posteriorly. In approximately one-

third of cases the atresia is bilateral.

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2 Hugh j. Williams MAY, 1971

Associated abnormalities of the surround-

ing bony structures, including a higharched hard palate, and an increased thick-

ness of the vomer, nasal septum and the

lateral nasal structures are often present,thereby reducing the diameters of thenasal fossa and the nasophar��nx. Thefrequent association of other congenital

anomalies has been well documented4 and a

familial incidence has been noted by some

authors.13 In the large series of Flake and

Ferguson,3 there was a twofold predomi-

nance of females over males. In patientswith unilateral choanal atresia the occur-rence was predominantly right-sided (over2: i).

SYM PTOMS

Ronaldson in 1 88 1 � recorded the first

clinical description of choanal atresia and

it has never been surpassed in clarity.Despite the classic description of bi-

lateral choanal atresia some 89 years ago,

many physicians are still unaware of the

lethal potential of this uncommon anomal��of the newborn. It is not generally appreci-ated that the newborn infant instinctively

breathes only through the nose, and thatoropharyngeal breathing is an acquired

function, which normally takes several daysto weeks to learn. This aversion to mouthbreathing has been attributed to an evolu-

tionary need for air currents to pass over

the olfactory area.7 The anatomic cross sec-tions of the infant skull performed byMoss5 demonstrate that the relatively

higher position of the cervical viscera

during infancy impedes access of air from

the mouth to the lower airway and that thenose is the best avenue for respiration. It

may be that this structural basis forobligatory nasal breathing in the newborn

plays a protective role against the aspira-tion of food. Because most neonates are

obligate nasal breathers, bilateral choanalatresia usually precipitates respiratory dis-

tress immediately after birth. This anom-aly, therefore, must be included in the

differential diagnosis of any newborn infant

suffering from respiratory distress. Failure

to consider this life threatening entity,establish the correct diagnosis, and

promptly institute appropriate therapy is

1.1 ndou b tedly responsi ble for an u nde ter-mined number of neonatal deaths fromasphyxia annually in the U.S.A. In those

infants who escape diagnosis in the firsthours of life because they rapidly learn

mou th-breathi ng, respi ratorv distress is

su ally precipitated subsequently by

attempts at feeding, since the ability to

simultaneously breathe and suck is seldomachieved until age 3-6 weeks.

All infants with bilateral choanal atresia

develop a thick, glairy, mucoid dischargefrom the nostrils. The copious, leathery

mucus may occasionally become blood

tinged but secondary infection seldom

supervenes. The external nares and upper

lip may become excoriated from the con-

stant mucus discharge from the nose.

Affected patients are unable to blow the

nose and the voice develops a nasal

quality. Anosmia and diminished taste are

present. The true diagnosis in those few

patients who do not manifest neonatal

respirator\� distress is often delayed, and

the nasal obstruction is erroneously attrib-

uted to allergy, rhinitis, deviate(l nasal

septum or enlarged adenoids.

The recent proposal � Shaw,” that

bilateral nasal obstruction from trivial

upper respiratory infection in the smallsleeping infant who does not instinctively

or voluntarily breathe through his mouth

is a significant factor in sudden unexpected

death of infancy, is an attractive one. More

than 15,000 infants under 6 months of age

die annually from this perplexing problem

and it constitutes the greatest cause of

mortality during the first year after the

neonatal period (2 to 3/1,000 live births).

NEW CLINICAL CLASSIFICATION

A new clinical classification of bilateralchoanal atresia, based on the rapidity with

which the newborn learns to both breathe

orally and to co-ordinate mouth breathing

and sucking, is proposed by the author

(Table II). It is hoped that this classifica-

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VOL. 112, No. i Posterior Choanal Atresia 3

TABLE I

SUMMARY OF CASES

Case Sex Location of Atresia Typ e (bilateral cases) Associated Anomalies

i. B.G.H. F Bilateral I (Fig. I, A and B)2. D.M. F Bilateral II3. G.J. NI Bilateral I Esophageal atresia

with fistula�. R.A.L. NI Bilateral III (Fig. 3, ii and B)�. A.L. I’ Left (Fig. �, A and B)6. J.M.C. NI Right (Fig. 4, 4 and B) Omphalocele7. B.G.l). F Bilateral Ill8. J.H. F Left Ventricular septal

defect and congenitaldeformity of externalright ear

�. M.H. Ni Right

io. L.C. F Bilateral II (Fig. 2, A and B)ii. M.W. M Right

12. G.W. M Left13. K.S. F’ Right14. L.S.J. F Left Mongolismi�. J.A. M Bilateral Ii6. C.D. F Right17. T.M. F Bilateral Ii8. B.W. I’ Bilateral I19. R.S. F Right

tion, by stressing the clinical rather thanthe anatomic aspects of the disease, willlead to a better understanding of thevarious manifestations of bilateral choanalatresia and hence to an earlier diagnosis.

Type I. These infants lack the ability torapidly learn the technique of oropharyn-

geal breathing and immediately develop air

hunger, cyanosis and chest retraction(Cases I, and 3). Type I comprises the

largest group (Table i) and these infantswill die from asphyxia unless an artificial

airway is immediately established. Pro-

longed use of such an airway is often re-

quired, but in many cases the infant can be

gradually weaned from it over a period of

weeks. These infants frequently cannot co-

ordinate mouth breathing and sucking and

attempts at feeding provoke respiratory

distress. Gavage feedings are usually neces-

sary in such infants and must be continued

after oropharyngeal breathing has been

mastered, until such time as the necessary

co-ordination between mouth breathing

and sucking develops.

Type II. This smaller group of infants

learns mouth breathing more rapidly afterbirth than do infants of Type i. Theirrespiratory distress is cyclic and less severe,

necessitating only transient or intermittent

use of an artificial airway (Case 2). How-

ever, even after the technique of oropharyn-geal breathing has been mastered (hours to

days), respiratory distress may still be

provoked by attempts at feeding. The

obviously ravenous infant will suckle only

spasmodically because the nipple causes

temporary occlusion of the oral airway.

Until such infants learn to co-ordinate oral

breathing and sucking (usually by the age

3-6 weeks), gavage feedings should be em-

ployed. Persistent, premature attempts to

orally feed such infants prior to develop-

ment of this co-ordination will result in

choking, cyanotic spells and aspiration

pneumonitis.

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No. ofcases

Type 1 5

Type II

Type III

Type IV 0

Time required

to mastermouth

breathing

Prolonged(weeks)

Hours to days

Immediate to

a few hours

None

Time required

to developco-ordinationbetween oral

breathing and

sucking

3-6 weeks

usually

�-6 weeks

usually

3-6 weeks

None

Airwayrequirements

Immediate,

prolonged

Intermittent

(hours to

weeks)

None

Type of

neonatalrespiratory

distress

Immediate,

severe andprolonged;

usually ag-

gravated by

feedings

Less severeand intermit-

tent; occurs

at rest and

usually dur-

ing feedings

Nlild at rest;

threateningonly during

feedings

Little or none

Need for

gavage orspecialized

nipple

feedings

I’requent

1’requent

les

None None

4 Hugh J. Williams

TABLE II

CLASSIFICATION OF I1ILATERAL CHOANAL ATRESIA

MAY, 1971

Type III. This still smaller group of infantsrapidly masters the technique of oralbreathing and any presenting respiratory

symptoms are mild. An artificial airway

is not necessary in this group. Nevertheless,

the necessary co-ordination between mouthbreathing and sucking has not yet been

learned. Air hunger and cyanosis, whichare only mild and occasional during ordi-

nary activities, become severe during at-

tempts at feeding (Case �). Because of thisrelationship between feedings and respira-

tory distress, an investigation of theesophagus for vascular ring, ectopic leftpulmonary artery or esophageal stenosis isoften mistakenly undertaken. Gavage feed-

ing, until such time as oropharyngealbreathing and sucking become co-ordi-

nated, is the only initial treatment required

in these infants.

Type IV. This very small group is com-posed of those few neonates who are for-

tunate enough to rapidly master both the

technique of oropharyngeal breathing andthe essential co-ordination between mouthbreathing and sucking. Infants in thisgroup manifest little or no respiratory dis-

tress and do not require use of an airway

or specialized feeding techniques. In in-fants with a complete absence of symptoms,

the condition may remain undetected for avariable period. None of the infants in thisseries fall in this category.

DIAGNOSIS

The diagnosis of bilateral choanal atresiais established clinically by the inability topass a firm rubber catheter or probe

through the nose into the nasopharynx.Positive confirmation can be made roent-genologically by obtaining lateral skullroentgenograms, following the instillation

of an opaque medium such as oily dionosil

into each nasal vestibule. Preliminaryinstillation of a pediatric strength nasal

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Posterior Choanal AtresiaVOL. 112, No. 5

decongestant into each nostril will elimi-nate the possibility of mistakenly diagnosing

nasal obstruction by edematous, inflamed

nasal mucosa for choanal atresia. This isparticularly important where the mother

has been receiving reserpine. Nasal con-

gestion occurs in approximately 10 per centof such infants and when severe may

occlude the nasal passages, thereby simu-

lating bilateral choanal atresia.6 This drug-induced nasal congestion may persist for� to 6 days following delivery. If desired,

the thickness of the occluding septum canbe determined by measuring the distance

separating the opaque medium in theposterior nasal cavity from the air column

in the nasopharynx. The opaque mediummust be flushed from the initially examined

nare before proceeding to examine theopposite nare. If prior use of an airway hasbeen found essential to prevent respiratory

distress, it should be left in place duringthe roentgenographic examination.

Unilateral choanal atresia is usually abenign condition with minimal symptoms,and is seldom diagnosed until later in

childhood or adult life (Case �). The chief

symptoms consist of a persistent nasalobstruction and a constant discharge from

the affected nostril. Unilateral atresia,

however, may assume real importance in

early infancy should the unobstructed nos-tril become occluded from rhinitis or othercause prior to mastery of the technique of

mouth breathing. Under such circum-stances a unilateral choanal atresia be-comes functionally converted into a bi-

lateral choanal atresia and severe respira-

tory distress may develop (Case 6).

TREATMENT

Since bilateral choanal atresia often

presents as a neonatal emergency, immedi-ate diagnosis and treatment are essentialto prevent death from asphyxia. Failure

to consider this congenital anomaly in the

newborn infant with severe respiratory dis-tress is responsible for an indeterminate

number of readily preventable deathsannually. In cases of Type i bilateral

choanal atresia, immediate establishment

and maintenance of an adequateoropharyngeal airway is essential and life-

saving. Gavage feedings are often necessary

subsequently in such infants. Correctivesurgery, the definitive treatment, can be

performed later as an elective procedure.In Type II infants, intermittent use of an

airway and gavage feedings should beemployed. Type III cases require onlygavage feedings during the neonatal period

and these may be discontinued when theafflicted infar�t learns to co-ordinate oral

breathing and swallowing. Type ‘iv casesrequire no therapy initially.

The definitive treatment in all types

of bilateral bony choanal atresia is surgicalresection of the septa. Surgical resection of

the obstructing bone via the transpalatalapproach is most commonly employed and

this operation can be successfully per-

formed during the neonatal period.’ Theposterior choanal diameter doubles during

the first year of life and for this reasonsurgery is often delayed until after 6

months of age, at which time it is tech-nically simpler. More recently McGovern4

has described the use of a large holedrubber nipple which is strapped in the in-fant’s mouth as a temporary means of

treatment. This ingenious, yet simple de-vice was invented by the concerned parents

of a child born with bilateral choanalatresia. By employing the McGovern

apparatus, definitive surgery may be safely

delayed for several months, when it be-comes technically simpler because of theincreased size of the operative area. A

modification of the McGovern nipple hasbeen successfully employed in several of

the more recent cases at our hospital (Case7).

In cases of bilateral membranous atresia,

transnasal puncture of the occluding mem-branes with a curved hemostat, followedby insertion of hollow tubing through each

nostril into the nasopharynx, can be readilyperformed during the neonatal period.Should stenosis occur after this procedure,

it can be treated by periodic dilatations.In patients with unilateral atresia (Case

�) surgical correction of the anomaly can

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FIG. i. Case 1. (4 and B) Newborn infant with Type i bilateral choanal atresia. Opaque medium injecte(linto both the right (4) and left (B) nasal cavities does not enter the nasopharynx. Note the endotracheal

airway which was required to prevent death from asphyxia.

6 Hugh .J. \Villianis M�’, 197!

be performed as an elective procedure any-

time following establishment of the diag-

nosis. The surgical technique is similar tothat in bilateral choanal atresia and the

transpalatal approach is most commonly

employed.

REPORT OF REPRESENTATIVE CASES

CASE 1. B.G.H. was a full term female in-

fant who breathed spontaneously at birth but

within seconds became cyanotic and struggled

to maintain respiration. The respiratory dis-tress was relieved by insertion of a pharyngeal

airway, but recurred immediately whenever the

airway was removed (Type i). The diagnosis

of bilateral choanal atresia was established

clinically by the inability to pass a rubber cath-

eter through either nostril and was confirmed

roentgenologically (Fig. i, A and B). Bilateral

transnasal perforation was carried out under

general anesthesia during the first day of life

and No. io French catheters were inserted

through both nostrils into the pharynx. On

awaking from the anesthetic the baby was ableto breathe readily through the catheters andtolerated its feedings well.

CASE 2. D.M., a full term female infant,

developed sternal retraction and cyanosis im-

mediately after delivery in another hospital.

This was felt to be due to prolapse of the tongue

into the throat and an airway was inserted,

with immediate relief of the symptoms. Fol-

lowing transfer at 6 hours of age, the airway

was removed and the baby breathed more easily,with only occasional episodes of sternal re-

traction (Type II). The diagnosis of bilateralchoanal atresia was established both clinically

and roen tgenologically. Cyanosis developed

whenever oral feedings were attempted, and

because of this gavage feedings were instituted.

By the age of 3 weeks, oral feedings could be

administered slowly by nipple without pro-

voking respiratory distress. Bilateral transpal-

atal repair was performed at the age of 8 weeks.

CASE 3. G.j. was a 2,500 gm. premature

male infant, the product of a pregnancy compli-

cated by toxemia and polyhydramnios. Res-

piratory distress and cyanosis began immedi-

ately after birth. The distress was relieved by

insertion of an airway, but recurred immediately

whenever an attempt was made to remove theairway (Type i). Neither a rubber catheter nor

opaque medium could be passed through either

nostril, confirming the diagnosis of bilateral

choanal atresia. A Type III esophageal atresia

with fistula was also present. In addition to the

above anomalies, the baby had low, deformed

ears and micrognathia. The esophageal atresia

was repaired immediately and a gastrostomy

performed. The treatment of the choanal atre-

sia consisted of a rigid pharyngeal airway for 3

days, followed by use of a McGovern nipple.

The infant gradually mastered mouth breath-

ing and by 3 weeks of age could tolerate short

periods without the nipple. By the age of �

weeks he could take small amounts of formulaorally, although sternal retraction and cyanosis

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VOL. 112, No. i Posterior Choanal Atresia 7

FIG. 2. Case 10. (A and B) Type II bilateral choanal atresia. The diagnosis was established both clinically

and roentgenologically during the first week of life. There was intermittent respiratory distress, aggra-vated by feeding, which responded to intermittent use of an airway and gavage feedings. At the time of

this contrast examination at the age of 2 years, the only symptoms present were bilateral nasal obstructionand a thick, persistent mucoid discharge from both nostrils. Oily dionosil injected into the right nare (A)

and left nare (B) fails to enter the nasopharynx. The child is now 5 years of age and has not had surgical

treatment.

sometimes occurred during feedings. At the age

of 7 weeks he was able to breath without the

open tip nipple and this was discontinued.

Large amounts of thick mucus were removed

by suction periodically from the occluded nos-

trils. He gained well until 5 months of age,

when he developed aspiration pneumonitis and

died of cardiac arrest. At autopsy the esopha-

geal anastomotic site was tightly stenotic.

CASE 4. R.A.L. was a full term male, born4 days prior to admission in another hospital.Numerous episodes of mild dyspnea and cya-

nosis occurred during the first hours of life butan airway was never required. Bronchoscopy on

3 occasions was negative. Attempts at feedingwere accompanied by severe cyanosis and

choking spells. The diagnosis of an overly re-laxed, floppy tongue was made and the babywas fed by gavage. There was a persistent,thick, tenacious mucoid discharge from bothnostrils and at times the mucus contained smallamounts of blood. Attempts to feed the babyorally by nipple following admission to Chil-

dren’s Hospital provoked chest retraction andmarked cyanosis. Gavage feedings were insti-

tuted, and the subsequent feedings were com-plicated by only mild cyanosis. The diagnosisof bilateral choanal atresia was established

clinically at i week of age by failure to pass acatheter through either nostril. This diagnosis

was confirmed roentgenologically using lipiodol

(Fig. 3, A and B). An esophagogram was nega-

tive. Bilateral transpalatal repair was per-

formed in this infant with Type III choanalatresia, with complete relief of symptoms.

CASE 5. A.L., a 12 year old female, wasseen because of a complete obstruction of the

left nasal cavity since birth. This had been ac-companied by an ipsilateral copious thick,

mucoid nasal discharge. On inspection, the left

nasal cavity contained a large amount of ten-

acious, glairy mucus. A catheter could not be

passed through the left nostril into the naso-

pharynx, but passed readily through the right

nostril. The diagnosis of unilateral left choanal

atresia was confirmed by a lipiodol study (Fig.

s, A and B). Surgery was performed electively6 months later and the thick bony septum was

resected through a transpalatal approach.

CASE 6. J.M.C. This full term, newborn

male infant was transferred to Children’s Hos-

pital because of a small omphalocele, which

was repaired uneventfully. There was no res-

piratory difficulty and the baby sucked well.

There was a large amount of thick mucoid dis-

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FIG. 3. Case �. (A and B) Type III bilateral choanal atresia. Numerous episodes of mild dyspnea and cyanosis

attributed to a lax tongue occurred during the first week of life, but did not necessitate an airway. Since

attempts at oral feedings resulted in choking and severe cyanosis, gavage feedings were utilized. Three

negative bronchoscopies were performed. Lipiodol examination at the age of I week of the right (A) andleft nares (B) revealed bilateral choanal atresia.

8 Hugh J. Williams MAY, 1971

charge from the right nostril. Choanal atresia

was suspected clinically, because a cousin had

been treated for this disease. A rubber catheter

could not be passed through the right nostril,

but passed readil through the left nostril into

the pharynx. The infant returned as an out-

patient 6 weeks later for contrast study confir-

mation of the previously diagnosed right choanal

atresia. Opaque medium injected into the right

nasal cavity failed to enter the nasopharvnx

(Fig. 4A). After flushing the medium from the

right nostril, the catheter was passed into the

nasopharynx (Fig. 4B), whereupon the infant

immediately developed severe respiratory dis-

tress, sternal retraction and cyanosis. Follow-

ing suction, mouth-to-mouth resuscitation, and

the administration of oxygen, normal breathing

resumed in several minutes. The baby was ad-

mitted for observation and discharged in good

condition some 24 hours later. Transpalatal

FIG. 4. Case 6. (A and B) The diagnosis of right choanal atresia was clinically established during the firstweek of life.Injection of contrast medium into the right nasal cavity at the age of 6 weeks confirmed the

diagnosis of unilateral choanal atresia (A). Contrast medium injected into the left nostril passed readilyinto the nasopharynx (B) and provoked immediate respiratory distress which necessitated emergency

measures. This case represents iatrogenic temporary conversion of a unilateral form of choanal atresiainto a Type I form of bilateral choanal atresia.

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VOL. 112, No. I Posterior Choanal Atresia 9

FIG. �. Case �. (A and B) This i 2 year old female presented with obstruction of the left nostril, accompanied

by a copious mucoid discharge from this nostril since birth. A catheter could not be passed through theleft nare into the pharynx. Lipiodol injected into the left nasal cavity did not enter the nasopharynx in

either the lateral (A) or submentovertical (B) views. A thick bony posterior septum was surgically re-

sected. Note the small amount of lipiodol which has entered the sphenoid sinus.

repair of the right choanal atresia was subse-

quently performed. Occlusion of the anatomi-

cally patent left choana by the puddled bolus of

opaque medium in the nasopharynx, in effect,converted this case of unilateral choanal atresia

into a Type I bilateral choanal atresia, pro-

ducing immediate, severe, respiratory distress.

CASE 7. B.G.D. This full term female in-

fant breathed promptly immediately after

birth and had a lusty cry. Shortly thereafter,

mild retraction developed but no airway assis-

tance was required. A chest roentgenogram re-

vealed a small pneumomediastinum. A catheter

could not be passed through either nostril, and

roentgenographic examination with a water

soluble medium confirmed the diagnosis of bi-

lateral choanal atresia. The pneumomediasti-

num resolved spontaneously and the infant had

no further difficulty in breathing at rest. At-

tempts at feeding through an ordinary nipple

produced a moderate degree of choking and

mild cyanosis. She was switched to a large

holed McGovern type nipple and the nurses

remarked on how well she mastered the tech-

nique of alternating breathing and sucking.

\Vithin 2 weeks her oral breathing and sucking

co-ordination had become so well developed

that she was able to feed through an ordinary

nipple without any respiratory distress. She

was discharged at the age of � weeks and elec-

tive surgery was planned at about i year of age.

There was a copious, thick, mucoid discharge

from both nares of this case of Type iii bilateral

choanal atresia during the period of hospital-

ization.

DISCUSSION

Choanal atresia is not rare, despite thepaucity of cases reported in the roentgeno-

logic literature. An incomplete search in

our community, prompted by the chrono-

logically rapid presentation of several cases

of choanal atresia at The Children’s Hos-pital of St. Paul, yielded 19 cases. All of

these were encountered in the past ioyears, and io of the patients presented

during the past 2 years. An analysis of

these cases (Table I) revealed that theatresia was bilateral in almost 50 per cent

of the patients (9 of 19). This incidence,however, is not truly representative of thebilateral frequency of this anomaly, since

many unilateral cases either escape diag-

nosis, or do not enter a hospital such as

ours following establishment of the diag-

nosis. The sex incidence in our series was

slightly higher in females than males (II

versus 8), but there was not the twofold

female predominance encountered in the

larger series of Flake and Ferguson.3 When

unilateral atresia was present in our series,there was no distinct preference for either

side, in contradistinction to the above

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10 MAY, 1971Hugh J. Williams

Illentioned series, where unilateral atresia

occurred twice as frequently on the right

side.’

Because of the ati thor’s dissatisfaction

with the anatomic classification of bilateral

choanal atresia which offers no assistanceto the clinician, a new classification of bi-

lateral choanal atresia has been devised

and is proposed (Table ii). This is a clinical

classification, based on the rapidity with

which the neonate learns to mouth-breathe

and to co-ordinate oral breathing with

sucking. It is hoped that this classification,as opposed to the traditional anatomic

classification, will orient the clinician

towards the varying clinical features ofbilateral choanal atresia. Hopefully thisapproach will lead to earlier diagnosis and

institution of appropriate treatment.The diagnosis of bilateral choanal atresia

is established clinically by failure to pass a

rubber catheter through either nostril into

the nasopharynx. Roentgenologic confirma-tion can be achieved by injecting an opaque

medium such as oily dionosil into eachnasal cavity. The initial treatment in

symptomatic infants consists of establish-ing an airway and employing specializedfeeding techniques. The recent introduc-

tion of the McGovern nipple has provided

an ingenious alternative form of temporary

treatment and allows definitive surgery tobe delayed until it is technically simpler.

This simple technique solves both therespiratory and feeding problems and obvi-

ates the need for an endotracheal tube or

tracheotomy in most cases.Unilateral atresia is usually a benign

condition and the diagnosis is frequentlynot established until later in life, when theaffected individual presents with the com-

plaint of unilateral chronic nasal obstruc-tion and discharge. Only rarely does uni-lateral choanal atresia produce a life

threatening situation, but this can occurif the uninvolved nostril becomes occludedby rhinitis or other cause before the infant

learns oral breathing (Case 6). Except inthese rare instances, the treatment ofunilateral choanal atresia is elective.

SUMMARY

I . Posterior choanal atresia is an tin-

common condition, but it is not as rare as

the scant radiologic literature would mdi-cate.

2. The findings in 19 cases of unilateral

and bilateral choanal atresia are presented,

with the emphasis on symptoms, diag-nosis, and treatment. It is stressed that the

newborn infant is an obligate nasal breatherand that oral breathing is an acquired

ability.

3. A new clinical classification of bi-

lateral choanal atresia, based on the easewith which the neonate learns both tobreathe orally and to co-ordinate mouth

breathing and sucking, is proposed as areplacement for the traditional anatomic

classification.

�. Bilateral choanal atresia must beruled out in any neonate with respiratory

distress. Failure to quickly establish the

diagnosis and institute immediate therapymay result in preventable death from

asphyxia.

�. Unilateral choanal atresia is usually abenign condition and elective therapysuffices.

The Children’s Hospital31! Pleasant Avenue

St. Paul, Minnesota 55102

The author wishes to express thanks tothe various radiologists and otorhinolaryn-

gologists in various Twin City Hospitalswho contributed cases and encouragement.

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3. FLAKE, C. G., and FERGUSON, C. F. Congenitalchoanal atresia in infants and children. Ann.

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4. MCGOVERN, F. H. Association of congenital

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