VOL.
No.
125,
Downloaded from www.ajronline.org by New York Medical College on 10/22/15 from IP address 64.118.223.43. Copyright ARRS. For personal use only; all rights reserved
THE
4
ROENTGENOLOGIC INVESTIGATION CONGENITAL SUBGLOTTIC STENOSIS* By MICHAEL
GRUNEBAUM,
PETAH-TIQVA,
OF
M.D.
ISRAEL
ABSTRACT:
Congenital nosed
by
subglottic the
correlation
stenosis,
which
of
clinical
the
is life-threatening and
the
to the
infant,
roentgenologic
can
findings.
be
diag-
The
main
clinical sign is the persistence of stridor from birth. The indicative roentgenologic finding is a symmetrical narrowing of the subglottic segment which is constant form and length during the various phases of the respiratory cycle. Two cases are presented, one confirmed by postmortem examination and other by endoscopy. The etiology of this condition and the differential diagnosis discussed.
U
NTIL recently, congenital subglottic stenosis was considered a rare entity usually discovered only on necropsy by the pathologist.5 With the diagnostic tools now available, this disease can be recognized during life and the affected infant can be helped.”2’4’6 It is the purpose of this presentation to outline the roentgenologic approach and the roentgenologic signs which indicate congenital subglottic stenosis.
in the are
This air column is centrally placed and cone-shaped, with its apex extending to the vocal cord region, and does not change in appearance during respiration. On fluoroscopy, during the inspiratory phase there is a marked distention of the hypopharynx by air with a widening of the mediastinal shadow. The reverse is ohserved during the expiratory phase of the respiratory cycle. As above, however, there is no
change
subglottic
in
the
shape
of
the
narrowed
segment.
METHOD REPORT
The
roentgenologic examination includes two phases: (I) A roentgenogram of the chest and neck on one film, using a high KV technique. Roentgenograms are obtained in two planes; (2) Fluoroscopy of the neck and mediastinum with spot films of the laryngeal and tracheal regions taken in the anteroposterior and lateral positions during inspiration and expiration.
CASE
from
the Pediatric
Radiology
Unit,
Beilinson
Medical
Center
birth
admission
three
had
OF
CASES
month
old
presented
female
noisy
infant
breathing
a marked
severe
dyspnea
noted.
Physical
inspiratory
and
sternal
examination
stridor
was On with
retractions showed
the
was lungs
to be equally aerated with an inspiratory and expiratory wheeze. The remainder of the examination was without pathological findings. The roentgenologic investigation included chest-neck roentgenograms and Iluoroscopy of the mediastinum with spot-films of the laryn-
On the chest roentgenograms and spot films, an air laryngogram is well visualized. This demonstrates a symmetrical narrowing of the subglottic region which is 2-3 mm in width and extends for a length of at least mm. The passage from the constricted segment to the extrathoracic trachea is abrupt and sharply outlined. From
A
which became worse during crying. She hospitalized because of increasing dyspnea.
RESULTS
*
I.
geal region. ing of the
During inspiration mediastinal shadow
of the
hypopharynx.
obtained
during
On the
the respiratory
there with various
was widendistention spot-films cycles
and
from different directions, an air laryngogram demonstrated a long, narrow segment in the subglottic region. In its proximal part, this air and the Tel Aviv University Medical
877
School, Petah-Tiqva,
IsraeL
Michael
Downloaded from www.ajronline.org by New York Medical College on 10/22/15 from IP address 64.118.223.43. Copyright ARRS. For personal use only; all rights reserved
878
Gr#{252}nebaum
-b Casei. Inspiratory
Spot films of the phase and (B)
i.
Marked
constant,
subglottic transition
from
thoracic
trachea black star).
(above
column
had
(A)
region.
expiratory
phase.
narrowing
of the
(black
arrow) with an abrupt the narrow segment to the extraand a distended hypopharynx
a symmetrical
Morgagni’s
ance.
laryngeal
symmetrical
region
cone-shaped
ventricle
2975
birth was known to have a “barking” voice which was diagnosed as chronic laryngitis. He was hospitalized because of increasing dyspnea during an upper respiratory infection. The physical examination revealed a cyanotic infant with marked inspiratory stridor. Fine rales were heard over both lung fields. The remainder of the examination was negative. An extensive roen tgenologic investigation disclosed a constant, symmetrically narrowed segment in the subglottic region (Fig. 3). On fluoroscopy, during inspiration the hypopharynx became distended, with a widening of the mediastinal shadow. Pneumonic infiltrates
I FIG.
DECEMBER,
was
were
spread
throughout
roentgenologic compatible
plicated The
findings with
both
were
lung
fields.
evaluated
a subglottic
The
as being
narrowing
by a patchy pneumonia
pneumonia. responded
Case i. Sagittal the extrathoracic appears normal.
section
to
com-
antibiotic
appear-
preserved
(Fig.
On the basis of the roentgenologic findings as well as the history of stnidor, a diagnosis of subglottic stenosis was made. Tracheal intubation performed because of increasing dyspnea brought immediate relief but during the night the tracheal catheter came out and respiratory arrest occurred. The infant was resuscitated, but expired soon after. Postmortem examination revealed a normal i).
epiglottis, aryepiglottic folds and cricoid cartilage. Beneath the true vocal cords, in the conus elasticus region, a symmetrical thickening of the wall covered with mucosa was seen narrowing the airway for a length of 8 mm, leaving a lumen of 1-2 mm in width. This tube-
like
formation,
color,
was
passage.
which
similar
The to
thick
wall segment
from
extrathoracic Microscopic
was
the
in the conus
unusual mass by connective encroaching on the
origin
the
narrow
air
seg-
elasticus
region
of striated muscle tissue beneath the lumen.
subglottic due
a grayish-red
tracheal lumen was examination of the
2).
The
of
obstructing
an
Comment. genital
was a ring
transition
ment abrupt revealed separated mucosa
the (Fig.
to
stenosis to
of con-
excessive
muscle
tissue. CASE
II.
A twelve
month
old
male
infant
from
FIG.
2.
and tricle
through
trachea. Severe
of the subglottic air-way tween the narrow lumen trachea.
with and
the
Morgagni’s concentric
a sharp the
larynx venstenosis
border extrathoracic
be-
Downloaded from www.ajronline.org by New York Medical College on 10/22/15 from IP address 64.118.223.43. Copyright ARRS. For personal use only; all rights reserved
VOL.
Congenital
No.
125,
treatment Repeat narrowing present. to the narrowed
Stenosis
879
-
but the inspiratory stridor persisted. roentgenograms showed that the of the subglottic segment was still Endoscopy revealed that the entrance subglottic region was concentrically with smooth borders. The patient
subsequently
was
Subglottic
hospitalized
several
times
because of increasing stridor. During one of these hospitalizations elsewhere, a tracheostomy was performed which improved the dyspnea. The patient succumbed at home during an episode ofpneumonia, and necropsy was not performed because of the family’s objection.
Comment. tal
origin
with
Subglottic stenosis a superimposed
*
of congenipneumonia.
DISCUSSION
Roentgenologic investigation of the stridulous infant is today a sine qua non. Whereas instrumental examination, such as indirect or direct laryngoscopy, is always potentially dangerous in a patient having stridor of unknown origin,’ roentgenologic investigation is a harmless procedure which can provide a great deal of information and can be of considerable assistance in establishing the cause of stridor. There are two major origins of congenital subglottic stenosis: anomalies of the cnicoid cartilage; or soft tissue anomalies in the walls of the conus elasticus in the subglottic region.5 Case I, in which the stenosis was
due
to
an
excess
of
striated
muscle
tissue beneath the mucosa, belongs to the latter category. The roentgenologic and endoscopic findings in Case II also favor this etiology. This condition can be diagnosed very early in life on the basis of the roentgenologic findings and should be suspected in any infant presenting a persistent inspiraTABLE THE
DIFFERENTIAL SUBGLOTTIC
I. 2.
3. 4.
I
DIAGNOSIS 5TENOSIS
Hemangioma Laryngeal
OF DURING
CONGENITAL INFANCY
or lymphangioma or subglottic web
Paralysis of the vocal cord Acute laryngotracheobronchitis
1
Lk FIG.
3. Case
laryngeal region. (A) Anteroposterior position and (B) lateral position. Narrow subglottic segment beneath the II.
Spot
films
of
the
normal-appearing Morgagni’s ventricle (black arrow in A) ; also well visualized in the lateral position (black arrow in B). The hypopharynx is distended with air (above black star).
tory stridor, as is demonstrated in the above two cases. It should be noted that the fluoroscopic finding of a widening of the mediastinal shadow during the respiratory phase is not pathognomonic of this entity, but indicates an incomplete respiratory obstruction above the tracheal bifurcation.3 From the roentgenologic point of view, the
differential
diagnosis
includes
several
other possibilities but these are easily ruled out (Table i). In cases of subglottic hemangioma or lymphangioma, the stenosis within the conus elasticus region is not symmetrical. With a laryngeal or subglottic web there is no narrow segment seen. Vocal cord paralysis, especially if unilateral, gives a picture of asymmetry of the vocal cords and of Morgagni’s ventricles. In acute laryngotracheobronchitis (croup) the stnidor
is
present
only
during
the
acute
Michael
Downloaded from www.ajronline.org by New York Medical College on 10/22/15 from IP address 64.118.223.43. Copyright ARRS. For personal use only; all rights reserved
88o phase signs
Gr#{252}nebaum
of the disease and the roentgenologic disappear when the stridor subsides.
Pediatric
Radiology
Beilinson
Medical
Petah-Tiqva,
Unit Center
4.
stenosis.
W. respiratory
EVANS,
J.
stridor: Radiol.,
J.,
SAUVEGRAIN,
children.
Ann.
radio/.
challenge 1973,
and
lesions diag.,
1973,
24,
MARE-
in infants 6, 293-
304.
5. PUVEENDRAM,
L. B. Congenital
BERGETROM,
7. Pediat.,
1973,
82,
case
282-
A.
Congenital
7. Laryng.
report.
subglottic
& Otol.,
1972,
atresia: 86, 847-
852.
284. 2.
D.,
C/in.
J. L. Laryngo-tracheal
SCHAL,
R. L., and
Respiratory
radiologist.
LALLEMAND,
and
subglottic
M.
for pediatric 485-490.
Israel
CUNDY,
1975
167-176.
3. GRIJNEBAUM,
REFERENCES .
DECEMBER,
A., JR. tract:
ROENTGENOL.
Congenital
tracheal & RAD.
obstructions
malformations. THERAPY,
1949,
of
6.
TAYBI,
AM.
trachea,
62,
Radio/.,
H.
Congenital bronchi
1967,
malformations and
I,
231-255.
lungs.
Frog.
of larynx, Pediat.
No.
125,
Downloaded from www.ajronline.org by New York Medical College on 10/22/15 from IP address 64.118.223.43. Copyright ARRS. For personal use only; all rights reserved
THE
4
ROENTGENOLOGIC INVESTIGATION CONGENITAL SUBGLOTTIC STENOSIS* By MICHAEL
GRUNEBAUM,
PETAH-TIQVA,
OF
M.D.
ISRAEL
ABSTRACT:
Congenital nosed
by
subglottic the
correlation
stenosis,
which
of
clinical
the
is life-threatening and
the
to the
infant,
roentgenologic
can
findings.
be
diag-
The
main
clinical sign is the persistence of stridor from birth. The indicative roentgenologic finding is a symmetrical narrowing of the subglottic segment which is constant form and length during the various phases of the respiratory cycle. Two cases are presented, one confirmed by postmortem examination and other by endoscopy. The etiology of this condition and the differential diagnosis discussed.
U
NTIL recently, congenital subglottic stenosis was considered a rare entity usually discovered only on necropsy by the pathologist.5 With the diagnostic tools now available, this disease can be recognized during life and the affected infant can be helped.”2’4’6 It is the purpose of this presentation to outline the roentgenologic approach and the roentgenologic signs which indicate congenital subglottic stenosis.
in the are
This air column is centrally placed and cone-shaped, with its apex extending to the vocal cord region, and does not change in appearance during respiration. On fluoroscopy, during the inspiratory phase there is a marked distention of the hypopharynx by air with a widening of the mediastinal shadow. The reverse is ohserved during the expiratory phase of the respiratory cycle. As above, however, there is no
change
subglottic
in
the
shape
of
the
narrowed
segment.
METHOD REPORT
The
roentgenologic examination includes two phases: (I) A roentgenogram of the chest and neck on one film, using a high KV technique. Roentgenograms are obtained in two planes; (2) Fluoroscopy of the neck and mediastinum with spot films of the laryngeal and tracheal regions taken in the anteroposterior and lateral positions during inspiration and expiration.
CASE
from
the Pediatric
Radiology
Unit,
Beilinson
Medical
Center
birth
admission
three
had
OF
CASES
month
old
presented
female
noisy
infant
breathing
a marked
severe
dyspnea
noted.
Physical
inspiratory
and
sternal
examination
stridor
was On with
retractions showed
the
was lungs
to be equally aerated with an inspiratory and expiratory wheeze. The remainder of the examination was without pathological findings. The roentgenologic investigation included chest-neck roentgenograms and Iluoroscopy of the mediastinum with spot-films of the laryn-
On the chest roentgenograms and spot films, an air laryngogram is well visualized. This demonstrates a symmetrical narrowing of the subglottic region which is 2-3 mm in width and extends for a length of at least mm. The passage from the constricted segment to the extrathoracic trachea is abrupt and sharply outlined. From
A
which became worse during crying. She hospitalized because of increasing dyspnea.
RESULTS
*
I.
geal region. ing of the
During inspiration mediastinal shadow
of the
hypopharynx.
obtained
during
On the
the respiratory
there with various
was widendistention spot-films cycles
and
from different directions, an air laryngogram demonstrated a long, narrow segment in the subglottic region. In its proximal part, this air and the Tel Aviv University Medical
877
School, Petah-Tiqva,
IsraeL
Michael
Downloaded from www.ajronline.org by New York Medical College on 10/22/15 from IP address 64.118.223.43. Copyright ARRS. For personal use only; all rights reserved
878
Gr#{252}nebaum
-b Casei. Inspiratory
Spot films of the phase and (B)
i.
Marked
constant,
subglottic transition
from
thoracic
trachea black star).
(above
column
had
(A)
region.
expiratory
phase.
narrowing
of the
(black
arrow) with an abrupt the narrow segment to the extraand a distended hypopharynx
a symmetrical
Morgagni’s
ance.
laryngeal
symmetrical
region
cone-shaped
ventricle
2975
birth was known to have a “barking” voice which was diagnosed as chronic laryngitis. He was hospitalized because of increasing dyspnea during an upper respiratory infection. The physical examination revealed a cyanotic infant with marked inspiratory stridor. Fine rales were heard over both lung fields. The remainder of the examination was negative. An extensive roen tgenologic investigation disclosed a constant, symmetrically narrowed segment in the subglottic region (Fig. 3). On fluoroscopy, during inspiration the hypopharynx became distended, with a widening of the mediastinal shadow. Pneumonic infiltrates
I FIG.
DECEMBER,
was
were
spread
throughout
roentgenologic compatible
plicated The
findings with
both
were
lung
fields.
evaluated
a subglottic
The
as being
narrowing
by a patchy pneumonia
pneumonia. responded
Case i. Sagittal the extrathoracic appears normal.
section
to
com-
antibiotic
appear-
preserved
(Fig.
On the basis of the roentgenologic findings as well as the history of stnidor, a diagnosis of subglottic stenosis was made. Tracheal intubation performed because of increasing dyspnea brought immediate relief but during the night the tracheal catheter came out and respiratory arrest occurred. The infant was resuscitated, but expired soon after. Postmortem examination revealed a normal i).
epiglottis, aryepiglottic folds and cricoid cartilage. Beneath the true vocal cords, in the conus elasticus region, a symmetrical thickening of the wall covered with mucosa was seen narrowing the airway for a length of 8 mm, leaving a lumen of 1-2 mm in width. This tube-
like
formation,
color,
was
passage.
which
similar
The to
thick
wall segment
from
extrathoracic Microscopic
was
the
in the conus
unusual mass by connective encroaching on the
origin
the
narrow
air
seg-
elasticus
region
of striated muscle tissue beneath the lumen.
subglottic due
a grayish-red
tracheal lumen was examination of the
2).
The
of
obstructing
an
Comment. genital
was a ring
transition
ment abrupt revealed separated mucosa
the (Fig.
to
stenosis to
of con-
excessive
muscle
tissue. CASE
II.
A twelve
month
old
male
infant
from
FIG.
2.
and tricle
through
trachea. Severe
of the subglottic air-way tween the narrow lumen trachea.
with and
the
Morgagni’s concentric
a sharp the
larynx venstenosis
border extrathoracic
be-
Downloaded from www.ajronline.org by New York Medical College on 10/22/15 from IP address 64.118.223.43. Copyright ARRS. For personal use only; all rights reserved
VOL.
Congenital
No.
125,
treatment Repeat narrowing present. to the narrowed
Stenosis
879
-
but the inspiratory stridor persisted. roentgenograms showed that the of the subglottic segment was still Endoscopy revealed that the entrance subglottic region was concentrically with smooth borders. The patient
subsequently
was
Subglottic
hospitalized
several
times
because of increasing stridor. During one of these hospitalizations elsewhere, a tracheostomy was performed which improved the dyspnea. The patient succumbed at home during an episode ofpneumonia, and necropsy was not performed because of the family’s objection.
Comment. tal
origin
with
Subglottic stenosis a superimposed
*
of congenipneumonia.
DISCUSSION
Roentgenologic investigation of the stridulous infant is today a sine qua non. Whereas instrumental examination, such as indirect or direct laryngoscopy, is always potentially dangerous in a patient having stridor of unknown origin,’ roentgenologic investigation is a harmless procedure which can provide a great deal of information and can be of considerable assistance in establishing the cause of stridor. There are two major origins of congenital subglottic stenosis: anomalies of the cnicoid cartilage; or soft tissue anomalies in the walls of the conus elasticus in the subglottic region.5 Case I, in which the stenosis was
due
to
an
excess
of
striated
muscle
tissue beneath the mucosa, belongs to the latter category. The roentgenologic and endoscopic findings in Case II also favor this etiology. This condition can be diagnosed very early in life on the basis of the roentgenologic findings and should be suspected in any infant presenting a persistent inspiraTABLE THE
DIFFERENTIAL SUBGLOTTIC
I. 2.
3. 4.
I
DIAGNOSIS 5TENOSIS
Hemangioma Laryngeal
OF DURING
CONGENITAL INFANCY
or lymphangioma or subglottic web
Paralysis of the vocal cord Acute laryngotracheobronchitis
1
Lk FIG.
3. Case
laryngeal region. (A) Anteroposterior position and (B) lateral position. Narrow subglottic segment beneath the II.
Spot
films
of
the
normal-appearing Morgagni’s ventricle (black arrow in A) ; also well visualized in the lateral position (black arrow in B). The hypopharynx is distended with air (above black star).
tory stridor, as is demonstrated in the above two cases. It should be noted that the fluoroscopic finding of a widening of the mediastinal shadow during the respiratory phase is not pathognomonic of this entity, but indicates an incomplete respiratory obstruction above the tracheal bifurcation.3 From the roentgenologic point of view, the
differential
diagnosis
includes
several
other possibilities but these are easily ruled out (Table i). In cases of subglottic hemangioma or lymphangioma, the stenosis within the conus elasticus region is not symmetrical. With a laryngeal or subglottic web there is no narrow segment seen. Vocal cord paralysis, especially if unilateral, gives a picture of asymmetry of the vocal cords and of Morgagni’s ventricles. In acute laryngotracheobronchitis (croup) the stnidor
is
present
only
during
the
acute
Michael
Downloaded from www.ajronline.org by New York Medical College on 10/22/15 from IP address 64.118.223.43. Copyright ARRS. For personal use only; all rights reserved
88o phase signs
Gr#{252}nebaum
of the disease and the roentgenologic disappear when the stridor subsides.
Pediatric
Radiology
Beilinson
Medical
Petah-Tiqva,
Unit Center
4.
stenosis.
W. respiratory
EVANS,
J.
stridor: Radiol.,
J.,
SAUVEGRAIN,
children.
Ann.
radio/.
challenge 1973,
and
lesions diag.,
1973,
24,
MARE-
in infants 6, 293-
304.
5. PUVEENDRAM,
L. B. Congenital
BERGETROM,
7. Pediat.,
1973,
82,
case
282-
A.
Congenital
7. Laryng.
report.
subglottic
& Otol.,
1972,
atresia: 86, 847-
852.
284. 2.
D.,
C/in.
J. L. Laryngo-tracheal
SCHAL,
R. L., and
Respiratory
radiologist.
LALLEMAND,
and
subglottic
M.
for pediatric 485-490.
Israel
CUNDY,
1975
167-176.
3. GRIJNEBAUM,
REFERENCES .
DECEMBER,
A., JR. tract:
ROENTGENOL.
Congenital
tracheal & RAD.
obstructions
malformations. THERAPY,
1949,
of
6.
TAYBI,
AM.
trachea,
62,
Radio/.,
H.
Congenital bronchi
1967,
malformations and
I,
231-255.
lungs.
Frog.
of larynx, Pediat.
