Acquired laryngotracheal stenosis

ACQUIRED LARYNGOTRACHEAL
STENOSIS
SCOTT BROWN LEARNING 2020
Volume-2(PEDIATRICS)
Chapter-31, Page 347-366
PRESENTER: Dr.MONISHA RM
MODERATOR: Prof.Dr.THANGARAJ MS,DLO

PEDIATRIC LARYNGEAL ANATOMY
Compared with the adult larynx, the infant larynx lies high in the neck,
with the hyoid bone overriding its superior aspect.
The narrowest point in the infant airway is the cricoid ring.
In a term newborn, the diameter of the subglottis is between 4.5 and
5.5 mm. If the airway diameter in the term newborn is less than 4 mm,
SGS is present.
The superior margin of the supraglottis comprises the superior edge of
the epiglottis, the aryepiglottic folds and the arytenoids, while the
inferior margin is at the level of the true vocal folds.

The glottis comprises the true vocal folds and the glottic chink.
In the infant, the posterior 50% of the true vocal fold consists of the
vocal process of the arytenoid.
The subglottis lies between the undersurface of the vocal fold and
the lower border of the cricoid cartilage.
The subglottic mucosa is lined with respiratory epithelium. A
transition to squamous epithelium occurs at the free edge of the true
vocal fold.

HISTORY
A child with laryngeal stenosis may present with
-stridor
-extubation failure
-tracheotomy dependency
In a child presenting with stridor, the duration of stridor must first be
ascertained.
If acute, stridor is a medical emergency. When it is more chronic, its
mode of onset should be ascertained and the determination of
whether it is stable or progressive should be made
The aetiology of the child’s compromised airway should also be
sought

In an intubated child, the reason for intubation should be assessed,
as should any medical problems that could contribute to extubation
failure.
The relevant history should include
-length of time the child was intubated
-the size of the endotracheal tube
-the number of attempts at extubation
-whether extubation failure abruptly occurred following ET
tube removal
-due to gradual and progressive respiratory compromise
necessitating reintubation.

In a child with tracheotomy dependency, the aetiology requiring
initial placement of a tracheotomy should be ascertained and the
duration of cannulation and size of the tracheotomy tube should be
determined.
Any history of airway reconstructive surgery is also extremely
important.
Another significant aspect of a thorough assessment is an
evaluation of voice quality and the ability to tolerate a speaking
valve.

PHYSICAL EXAMINATION
The presence of stridor and retractions at rest should be
assessed.
The nature of the stridor — INSPIRATORY/EXPIRATORY/BIPHASIC
Assessment of voice quality
>supraglottic stenosis - muffled or ‘throaty’ voice
>anterior glottic webbing - very hoarse voice.
>posterior glottic stenosis and SGS - normal voice quality.

IMAGING STUDIES
Imaging studies fall into two time-related categories: those that are
performed prior to endoscopic evaluation and those that are best
after endoscopic evaluation.
Prior to endoscopy, soft-tissue airway films of the neck and chest
should be performed in both lateral and anterior/posterior
projections.
These are useful in evaluating laryngeal stenosis and may also give
timely warning of a possible tracheal stenosis. Anterior/posterior
and lateral chest films indicate possible underlying lung pathology

Barium swallow study
>ability to swallow
>the relative risk of aspiration
>need to evaluate the airway for a posterior laryngeal cleft or a
tracheoesophageal fistula.
>child’s propensity to gastro-oesophageal reflux
>vascular compression of the airway
>presence of an oesophageal foreign body.

CT AND MRI
Spiral computed tomography (CT) scanning of the airway with
contrast enhancement provides a useful view of intrathoracic
vasculature. If relevant, 3D reconstruction of CT axial images may be
valuable in evaluating the intrathoracic airway.
Although both magnetic resonance imaging (MRI) and magnetic
resonance angiography (MRA) also provide excellent views of
intrathoracic vascular anatomy, they require more time to perform
and are more likely to require sedation or anaesthesia.
In children with upper airway compromise, sleep fluoroscopy or cine
MRI may provide a valuable dynamic airway assessment.

ENDOSCOPIC EVALUATION
The most important information to be sought relates to vocal cord
movement
The ability of the vocal cords to normally abduct is critical information
prior to any consideration of laryngeal reconstructive surgery, whether
movement is compromised by unilateral or bilateral vocal cord paralysis,
posterior glottis stenosis, or cricoarytenoid joint fixation.
Although the risk of inducing laryngospasm is low, it is recommended that
the nasopharyngoscope should not be advanced below the level of the
glottis.
Although the precise mechanism is unclear, even children with bilateral
true vocal fold paralysis may have laryngospasm.

RIGID ENDOSCOPY
In a child with a compromised airway who does not have a tracheotomy
tube, preoperative administration of dexamethasone, 0.5 mg/kg up to a
maximum of 20 mg, is a prudent precaution.
‘gold standard’ for paediatric airway evaluation, and this evaluation should
begin with an assessment of the supralaryngeal airway.
The possible presence of retrognathia
glossoptosis
difficulty of laryngeal exposure
tonsillar hypertrophy
evidence of pharyngeal scarring should be assessed

The supraglottic larynx should be carefully assessed for scarring,
laryngomalacia, short aryepiglottic folds and arytenoid prolapse.
The glottis should be evaluated for scarring, anterior glottic webbing
and posterior glottic stenosis, and care should be taken to exclude the
presence of a posterior laryngeal cleft.
If vocal motion is clearly seen, it can be assumed that neither true
vocal cord is paralyzed.
If, however, movement is not observed, nasopharyngoscopy with the
patient awake should be performed.

The subglottis should be evaluated, and any stenosis or scarring
noted.
If stenosis is present, its severity, length, position and physical
characteristics should be noted.
It may be characterized as soft or firm, as concentric or with lateral
shelving, and with mucosa appearing either quiescent or actively
inflamed.

If there is a sufficient lumen to allow passage of the endoscope,
the trachea is next assessed.
An assessment is made of the upper trachea, including the
tracheotomy stoma site, looking for suprastomal collapse or
the presence of a suprastomal granuloma.
Assessment is also made of possible tracheomalacia and
vascular compression of the airway.
Although complete tracheal rings are rare, their possible
presence should be evaluated cautiously, so as not to induce
oedema within an already compromised segment of airway.
The carina and mainstem bronchi are also evaluated

If SGS has been identified, the area of stenosis should be graded
according to the Myer–Cotton classification
This is best carried out utilizing endotracheal tubes, with a small tube
being placed initially.
If this tube leaks at less than 20 cm of water pressure through the
subglottis, the next larger size is placed.
It should be noted that the Myer–Cotton grading system is not
designed to address supraglottic, glottic or tracheal stenosis

ANAESTHETIC TECHNIQUE DURING
BRONCHOSCOPY
A collaborative relationship with the anaesthetist is essential in deciding
upon the specific anaesthetic technique to be used when performing
rigid endoscopy.
Possible options include spontaneous ventilation, assisted ventilation,
jet ventilation, total intravenous anaesthesia (TIVA) and apnoea with
intermittent bag and mask ventilation
We prefer to use the Hopkins rod telescope, exposing the larynx with a
straight anaesthetic laryngoscope blade. The child spontaneously
ventilates a mixture of sevoflurane and oxygen through an endotracheal
tube placed in the oropharynx, and with additional intravenous
anaesthesia provided by propofol bolus.

FLEXIBLE BRONCHOSCOPY
Rigid bronchoscopy provides a superior assessment of the larynx,
especially the posterior glottic area.
Flexible bronchoscopy is often extremely valuable in assessing a
larynx that is difficult to access with rigid instrumentation and may
provide valuable information about airway dynamics, such as the
degree of pharyngeal collapse, glossoptosis and the presence of
laryngomalacia, tracheomalacia or bronchomalacia.
 Flexible bronchoscopy also permits evaluation beyond the eighth
generation of bronchi in older children and allows specific lavage of
bronchial subsegments, which may provide information about silent
aspiration if lipid-laden macrophages are found.

GASTROINTESTINAL EVALUATION
OESOPHAGOGASTRODUODENOSCOPY,
OESOPHAGEAL BIOPSY AND PH PROBE
In selected cases, particularly in patients with complex underlying medical
conditions or in those who have failed previous airway reconstruction,
oesophagogastroduodenoscopy may be beneficial in the assessment of a
child prior to airway reconstruction.
It can provide information about oesophagitis, gastritis, and the status of
the lower oesophageal sphincter, especially in regard to whether a
previous fundoplication is still functional.
Pre-operative evaluation of gastro-oesophageal reflux with dual probe pH
or impedance monitoring and/or oesophageal biopsy is advisable and
should be mandatory in a child with an active larynx or recalcitrant airway
stenosis following previous reconstruction.

Oesophageal biopsy will also provide information about oesophagitis
including the possibility of eosinophilic oesophagitis, and is currently
the best method of diagnosing and monitoring this condition.
Patients should be off antireflux medication for at least 1 week prior to
pH probe placement.
The impedance probe not only measures acid but can also provide an
indication of the volume of a reflux bolus and the height in the
oesophagus to which it progresses.
Impedance technology also allows evaluation of non-acid reflux. This
enables a child to remain on antireflux medication prior to evaluation.

EVALUATION OF ASPIRATION
Recurrent pneumonia
Insidious drop in a child’s baseline oxygen saturation
A history of previous aspiration or current aspiration is extremely
important.
In a child who is tracheotomy-dependent, copious tracheotomy
secretions or secretions stained by food material indicate chronic
aspiration.

SLEEP EVALUATION
A formal sleep evaluation may be a useful method to evaluate a child’s respiratory
efforts and oxygen needs, whether or not a tracheotomy is in place. The primary aim
of laryngotracheal reconstruction is decannulation, and this operative procedure is
rarely warranted if decannulation cannot be achieved.
 In children with tracheotomy dependency, it is important to evaluate whether
surgical correction of laryngeal stenosis will permit decannulation.
In children with significant lung disease, particularly bronchopulmonary dysplasia or
in those who are dependent on a ventilator or CPAP, decannulation may be
imprudent.
Similarly, children with progressive neuromuscular disorders, diaphragmatic
weakness or central hypoventilation syndrome may not be candidates for
decannulation.
If results of a sleep evaluation indicate pulmonary compromise that precludes
decannulation, laryngeal reconstruction may be futile.

VOICE EVALUATION
Voice evaluation in children with laryngeal stenosis, tracheotomy
dependency or following laryngotracheal reconstruction is in its infancy
and is poorly understood.
It is clear, however, that laryngeal reconstruction frequently has a
negative impact on the voice, particularly in children requiring
supraglottic or glottic surgery and in those in whom a laryngofissure is
required to reconstruct the airway.
What is unclear is which underlying pathologies and reconstructive
procedures place the voice at greatest risk, and also the extent to which
a voice disorder relates to the initial aetiology of the laryngotracheal
stenosis.

Children have a tremendous drive to communicate, which often
compensates for severe anatomic dysfunction.
Some children will retain a surprisingly good-quality voice, even with
a grade III SGS. However, children with a grade IV SGS are aphonic
unless they have learned oesophageal speech techniques.
In these children, laryngotracheal reconstruction may be extremely
beneficial in terms of regaining voice, even if decannulation is not
achieved

CONSIDERATIONS PRIOR TO LARYNGEAL
RECONSTRUCTION
Oxacillin or methicillin-resistant Staphlococcus aureus (MRSA)
screening prior to open airway surgery is also recommended, as post-
operative infection may greatly compromise the surgical repair.
In some of these children, azithromycin given as an anti-
inflammatory drug on a Monday, Wednesday, Friday dosing regimen
may be effective in reducing inflammation in up to 50% of children
with an idiopathic active larynx.

Although weight is a less important factor than the overall health
status of a child and the child’s laryngeal disease, it is a frequently
used criterion for postponement of airway reconstruction.
While laryngotracheal reconstruction can be effectively performed in
children less than 3 kg if other criteria permit, a 10 kg guideline is
often used

MEDICAL THERAPY
In the inflamed or active larynx, however, medical therapy plays an
important role in alleviating potential for a successful operative
outcome.
Medical therapy for an inflamed larynx revolves around treatment of
gastro-oesophageal reflux disease or eosinophilic oesophagitis.
If reflux is diagnosed or even suspected, then a low threshold for
treatment with H2 antagonists or proton pump inhibitors is
recommended.
In children with recalcitrant acidic reflux or significant nonacid reflux,
consideration should be given to performing fundoplication.

Eosinophilic oesophagitis has a characteristic appearance on
oesophagogastroduodenoscopy, with oesophageal furrows often
having microscopic white plaques noted.
However, the definitive diagnosis is made on biopsy, with greater than
20 eosinophils per high-power field being noted.
In children with eosinophilic oesophagitis, evaluation for underlying
food allergies is indicated. In children in whom a food allergy is not
proven, treatment with oral fluticasone is suggested.
An initial dosing regimen of 440 μg, sprayed on the tongue twice a day
and swallowed, is usually efficacious.
Follow-up oesophagoscopy with further biopsies to confirm resolution
of disease is suggested prior to undertaking laryngeal reconstruction,
which is usually delayed for 6 months.

TRACHEOTOMY
In a child with an unsafe or unstable airway in whom laryngotracheal
reconstruction is not immediately advisable, temporary placement of a
tracheotomy tube is advisable to secure an adequate airway until laryngeal
reconstruction can be performed.
Placement of a tracheotomy should be performed with a view to the
subsequent laryngeal reconstruction that may be required.
A high tracheotomy close to the cricoid increases the risk of exacerbation of
stenosis, but it may make subsequent cricotracheal resection (CTR) simpler, as
a shorter segment of airway can then be resected.
Tracheotomy through the second to fourth tracheal rings is still
recommended.

Although a tracheotomy provides a safer airway in a child with
laryngotracheal stenosis, the airway is by no means completely safe.
Tracheotomy-related deaths continue to occur in children who could
otherwise anticipate good long-term quality of life, and the greater
the degree of obstruction, the greater the risk.
A tracheotomy is a marked compromise on both a child’s and a
family’s quality of life and emotional health.

ENDOSCOPIC MANAGEMENT OF SUBGLOTTIC
STENOSIS
Children with grade I or II stenosis and no history of endoscopic
failure have a higher likelihood of successful endoscopic
management, whereas those with more severe SGS or multilevel
stenoses are more likely to require open reconstruction

BALLOON DILATION
Balloon dilation of the airway using high-pressure noncompliant
balloons has evolved considerably in recent years and is now
considered an invaluable addition to the tools used to manage
SGS,reportedly reducing the need for open airway surgery by as much
as 80%.
Purely radial force over the circumference of the stenosis, thus
minimizing the risk of airway rupture or mucosal trauma.

Pressures of over 20 atmospheres may be applied by some balloons.
By using a device that incorporates a pressure gauge, they also allow
the surgeon to fine-tune the force applied to the stenosis.
A third advantage is that balloon dilation catheters are long, narrow
and flexible — all of which allow the surgeon to steer through a
severe stenosis.
Selection of balloon size is based on the expected size of the normal
airway.

Repeated dilation at 1- to 3-week intervals on up to four occasions is
recommended.
 Adjunctive interventions such as steroid injection and scar division
may provide additional benefit, especially in patients with established
thicker stenosis.
Scar division may be performed utilizing a sickle knife, microlaryngeal
scissors or a laser.

Children who are likely to respond well to this technique are those
with thin or web-like and soft stenoses consisting of immature scar
tissue.
In contrast, patients with firm or mature scar tissue, cartilaginous
airway narrowing, and structural problems of the airway exoskeleton
(e.g. subglottic lateral shelves, missing cartilage) are less likely to
respond.
Dilation is also less likely to yield positive outcomes in longer
stenoses and in patients with additional airway lesions.

The recommended technique for balloon dilation is having the
patient not be forcefully breathing during the procedure; therefore,
after an initial evaluation of the airway, the patient is pre-oxygenated
and then either briefly paralyzed or given a bolus of propofol to
minimize spontaneous respiration.
The balloon is introduced with direct visualization with a Hopkins rod
endoscope, and then inflated to the rated burst pressure.
Care should be taken that the balloon does not displace (watermelon
seeding).
The balloon is kept inflated for 2 minutes or until the patient
desaturates to 90%, and it is then deflated and removed

COMPLICATIONS
Negative pressure pulmonary oedema
Airway rupture
Distal displacement
Success rate is lower than that seen with open airway reconstruction.
If after four or five dilations the airway diameter has not significantly
improved, then open surgery should be considered.
Given that balloon dilation is relatively simple, fast and low-risk in
children with mild to moderate degrees of SGS, it should be seriously
considered prior to open airway reconstruction.

LARYNGEAL RECONSTRUCTION
The mainstay of laryngotracheal reconstruction is expansion cartilage
grafting
In the subglottis, an alternative to this approach is resection and
reanastomosis.
Stenosis involving the supraglottis and anterior glottis is amenable to
laryngoplasty without cartilage grafting.
Whether congenital or acquired, tracheal stenosis may be best
managed by a slide tracheoplasty

GRAFT MATERIALS
Costal cartilage is the most widely used grafting material, with
excellent results noted on prolonged followup
The usual donor site is the right fifth or sixth rib
The harvested graft should include the perichondrium on the lateral
aspect of the graft, while leaving the inner perichondrial layer intact
at the donor site
Once the graft is harvested, filling the wound with saline and
performing a Valsalva manoeuvre will ensure that a breach of the
pleura has not occurred.

When the graft is carved to the desired shape, the perichondrium
should face the lumen of the airway; lateral flanges will prevent
prolapse of the graft into the airway.
When only a small graft is required, thyroid ala is a useful material.
This is usually taken from the upper aspect of the thyroid cartilage on
one side, at least 1 mm above thelevel of the true vocal cord.
Thyroid ala has the advantage of being quickly and easily harvested
from within the surgical field.
However, only a limited amount of grafting material is available and it
is not amenable to being carved with flanges

Auricular cartilage is also useful, in particular for the management of
suprastomal collapse as part of a single stage procedure.
It is easily harvested and reasonably abundant.
It makes an ideal cap or overlay graft, particularly over a stoma site,
but it is comparatively weak and not appropriate for insertion
between the cut edges of the cricoid.
In both adults and older children, there is no cosmetic donor site
deformity; however, in children younger than 1 year of age it is
common to have some residual asymmetry of the ears

Other grafting materials include buccal mucosa, septal cartilage, and
a pedicled hyoid bone interposition graft.
The results utilizing these grafting materials in children have been
disappointing. Another described technique is the use of a clavicular
periosteal graft, with its vascularity maintained by swinging the graft
up on a pedicle of sternocleidomastoid muscle.
This is a useful graft for older children in whom there is a significant
deficit of tracheal cartilage, as after several months the graft will start
to ossify, thereby providing support to the airway.
In prepubescent children, the graft unfortunately seems less
amenable to ossification, leaving the airway malacic

STENTS
Not all laryngotracheal reconstruction techniques require stent
placement.
Stenting maintains a lumen and prevents graft prolapse during post-
operative healing, and it may remain in place for days to months.
Longer-term stents are advisable when the laryngeal repair is
unstable or in a recalcitrant larynx that has failed previous
reconstruction

The most commonly used stent is the silicone Rutter suprastomal stent
although Abouker, Monnier and Mehta stents are also available.
The Rutter stents are soft and deformable and do not interfere with
placement of the tracheotomy tube.
They tend to incite less granulation tissue at the distal end of the stent, and
there is less dead space between the distal end of the stent and the
tracheotomy tube in which scarring can occur.
The proximal end of the stent is trimmed to the level of the false vocal cord
and then plugged with a rounded cap that is less likely to induce epiglottic
granulation tissue.
Unlike the rigid Abouker Teflon stents, these soft silastic suprastomal stents
may remain in place for longer than 6 weeks.
There is a corresponding restriction of speech, as they permit only very
limited air passage.

For longer-term stenting, tracheal T-tubes are recommended.
Although T-tubes with an outer diameter of 5 mm are commercially
available, because of the risk of crusting and obstruction, we do not
routinely place T-tubes with an outer diameter of less than 8 mm.
An 8 mm tube may be placed in a child as young as 4 years of age.
Following laryngeal reconstruction, the upper end of a T-tube is generally
passed through the vocal cords.
Aspiration is therefore a significant risk and is expected for 2 weeks
following stent placement. A supraglottic swallow technique is readily
achieved by most children, minimizing the risk of aspiration.
Unlike tracheotomy tubes, T-tubes cannot be easily changed. Meticulous T-
tube care is thus essential.

SINGLE STAGE RECONSTRUCTION
In children in whom a stenting period of less than 2 weeks is anticipated,
an option to be considered is intubation, with the endotracheal tube
acting as the stent.
Intubation for longer than 2 weeks, however, risks redevelopment of
posterior glottic stenosis or SGS
Most children can be extubated within 2–7 days of a CTR or an anterior
costal cartilage graft. Those with anterior/posterior cartilage grafts are
usually intubated for 7–14 days. The older the child, the more forgiving the
airway and the briefer the period of intubation required.
For more complex airway surgery, a prolonged period of intubation is
required.

A prerequisite for single-stage laryngotracheal reconstruction is an
excellent intensive care unit (ICU) in which staff are familiar with the
management of airway patients.
It is undesirable for a child to have an unplanned self-extubation, and
security of the nasotracheal tube is paramount.
Therefore, in younger children, the use of arm restraints and sedation is
usually required. Most children younger than age 3 require sedation, and
children who have been previously intubated for long periods may require
heavy sedation.
Paralysis is undesirable, as in the event of accidental decannulation, the
child is unable to maintain an airway and reintubation must be emergent.
Since any child undergoing a single-stage procedure risks the need for
reintubation, single-stage procedures should not be performed on children
who are difficult to intubate.
In the sedated child, commonly encountered problems include lung
atelectasis, fluid overload from heavy sedation, pneumonia and narcotic
withdrawal following extubation.

In children older than age 3 years with no major cognitive problems,
sedation may not be required.
Some of these intubated children may be able to ambulate, eat and
visit the playroom. A fully awake child does not require ventilatory
support and is less likely to have pulmonary complications from the
intubation
The day prior to extubation, returning to the theatre to inspect the
airway and downsize the tracheotomy tube is advisable.
If the airway appears adequate to support extubation, a dose of
dexamethasone, 0.5 mg/kg, is administered the night before
extubation, and the patient is extubated while fully awake

Poor candidates for singlestage reconstruction include
children with poor pulmonary function
those who are difficult to intubate
those with recalcitrant airway disease who have failed previous
reconstruction
those with complex disease involving multiple levels of obstruction.

SUPRAGLOTTIC STENOSIS
rare, difficult to treat, and is
frequently associated with supraglottic
collapse.
While severe supraglottic stenosis may
present with stridor, the primary
complaint is more commonly
obstructed breathing during sleep.
Therefore, a sleep study may be
extremely useful in the non-
tracheotomized patient or in the
patient in whom the tracheotomy can
be capped, even if for a brief period.

The underlying aetiology is often traumatic, due to severe direct
airway trauma or airway burns, or is of iatrogenic origin.
Supraglottic stenosis with associated collapse is a feature of the
airway that has undergone numerous laryngeal reconstructions.
Rigid endoscopic evaluation with the larynx suspended by a
laryngoscope may distort the appearance of the larynx, providing
false reassurance about the supraglottic airway.
Flexible endoscopic evaluation with the patient spontaneously
ventilating allows for superior evaluation of the airway dynamics

In children with mild to moderate supraglottic stenosis and collapse,
nocturnal CPAP may be very beneficial.
The most common patterns of supraglottic compromise are
arytenoid prolapse and epiglottic petiole prolapse.
Arytenoid prolapse is a dynamic instability of the arytenoid, either
unilateral or bilateral. It is characterized by its anterior displacement
during inspiration, which may cause significant airway obstruction.
This problem most commonly follows previous CTR or previous
laryngotracheal reconstruction involving division of the posterior
cricoid plate.

Arytenoid prolapse is usually managed endoscopically, using a laser
to perform a partial arytenoidectomy.
The preferred technique is to raise a mucosal flap and debulk the
prolapsing cartilage of the arytenoid without damaging the mucosal
‘diamond’ of the laryngeal inlet.
Injudicious use of the laser in the laryngeal inlet predisposes patients
to scar formation, fibrosis and narrowing of the supraglottic airway.

EPIGLOTTIC PETIOLE COLLAPSE
obscuring the anterior true vocal folds and foreshortening the
anterior/posterior diameter of the laryngeal inlet.
This problem is most commonly seen in children who have had repeated
previous laryngofissure and is a consequence of damage to the
thyroepiglottic ligament
Epiglottic petiole prolapse is rare, and challenging to treat. Injudicious use
of a laser in the endolarynx tends to exacerbate the problem, with further
scarring narrowing the laryngeal inlet.
Suspension of the epiglottic base to the hyoid bone provides some benefit,
but is technically challenging and causes the patient significant pain on
swallowing for several weeks post-operatively.

Our current management of this challenging problem is to perform a
complete laryngofissure and reposition the epiglottic petiole back up
to the inner surface of the thyroid ala.
The laryngofissure is then closed over a T-tube or suprastomal stent
and left in position as a translaryngeal stent for at least 2 months.
These patients may have problems with aspiration for some weeks
post-operatively

ACQUIRED ANTERIOR GLOTTIC WEBS
Anterior glottic webs are most commonly congenital in origin, and
are usually associated with a subglottic extension of the web resulting
in coexistent SGS
Acquired anterior glottic webs are less common and are post-
traumatic in origin.
There are two common aetiologies: anterior neck trauma, often
associated with a fractured larynx; and iatrogenic damage, often
associated with injudicious use of a laser at the anterior commissure
while managing laryngeal papillomatosis

The management of acquired anterior glottic stenosis differs significantly
from the management of the congenital anterior glottic web.
The latter has normal mucosa within the remaining glottic inlet, and during
reconstruction there may be sufficient mobility of the mucosal layer to
reconstruct the anterior commissure without requiring the use of a
laryngeal keel.
In contrast, acquired anterior glottic stenosis is, by definition, associated
with fibrosis and scarring.
As such, during reconstruction, following laryngofissure, the mucosa is
fibrotic and not amenable to reconstruction of the anterior commissure.
Therefore, reconstruction with placement of a laryngeal keel is mandatory
while the raw surfaces on either side of the laryngofissure remucosalize

The usual technique for repair of an acquired anterior glottic web is an
open approach with complete laryngofissure, and it is recommended that
this is performed with endoscopic guidance.
With the laryngofissure complete, the demucosalized raw scar of the
anterior vocal folds is noted and, in some cases, there may be enough
mucosal mobility to place a pexing suture from the cut edge of the mucosa
on either side towards the thyroid ala
An appropriate size laryngeal keel, such as the Montgomery Keel,™ is then
selected and trimmed.
The vertical limb of the keel should not impinge into the posterior
commissure. The vertical height of the keel should separate the raw
surfaces of the laryngofissure.
The upper limit of the keel should not be so high as to disrupt the insertion
of the epiglottic petiole.

The keel is then sewn into place and the laryngofissure closed. This
procedure is normally performed as a two stage procedure, although
a single-stage procedure may be performed with the patient
intubated and with the endotracheal tube lying on one side of the
vertical limb of the keel.
In some children, there is an associated component of SGS, and a
decision should be made as to whether the cricoid can be closed
adequately over an age-appropriate endotracheal tube.
If this is possible, the lower end of the keel should not extend beyond
the cricothyroid membrane.
If it is not possible, an anterior cartilage graft is placed in the anterior
cricoid, distal to the keel.

The keel is removed through an open approach between 10 days and 4
weeks post-operatively. The resultant midline deficit in the thyroid ala is
then closed with laterally placed mattress sutures, as the cartilage edges of
the laryngofissure are friable and easily damaged if sutures pull out.
For this reason, antibiotic coverage and antireflux measures are advised
during the period that the keel is in place, and for an additional few days
after keel removal.
Endoscopic placement of the laryngeal keel is increasingly a consideration.
The keel may be fashioned from a thin piece of silastic sheeting, with a
central suture orientated in the anterior midline across the divided web,
and with the silastic sheet placed like the leaves of a book over the divided
mucosa.
The suture may be placed as an ‘inside-out’ technique using a
Lichtenberger needle driver or as an ‘outside-in’ technique using a Keith
needle and hollow angiocath

POSTERIOR GLOTTIC STENOSIS
Posterior glottic stenosis is frequently
misdiagnosed and often confused with bilateral
true vocal cord paralysis.
It may exist as an isolated entity or in
combination with SGS. The most frequent
aetiology of this condition is prolonged
intubation, with the older child being at greater
risk than the neonate.
The posterior glottis is also susceptible to
damage from thermal injury caused by
inhalational or airway fires or to iatrogenic
damage from use of the laser in the posterior
commissure.
Occasionally, posterior glottic stenosis may be a
result of direct laryngeal trauma.

If not already tracheotomy-dependent, patients present with stridor
and exertional dyspnoea. Normal vocal function is usually preserved
and, in this regard, presenting symptomatology is similar to that seen
in bilateral vocal cord paralysis or cricoarytenoid joint fixation
Definitive diagnosis requires assessment with rigid bronchoscopy,
which confirms the presence of posterior glottic scarring, as a rigid
telescope provides excellent visualization of the posterior glottis.
Posterior glottic stenosis can, however, be misdiagnosed on
bronchoscopy if the telescope is passed directly through the vocal
folds to evaluate the subglottis without proactive inspection of the
posterior glottis.
Bronchoscopic evaluation should also include assessment of the
subglottis, which is frequently involved with scarring.

Flexible bronchoscopy provides a poor view of the posterior glottis
and is an inadequate method of diagnosing posterior glottic stenosis
The usual finding is that the vocal folds are mobile but tethered and
unable to abduct.
The differential diagnosis for posterior glottic stenosis commonly
includes SGS (which frequently may also be present), an
interarytenoid scar band, and cricoarytenoid joint fixation.
Bilateral vocal cord paralysis and posterior glottic stenosis rarely
coexist.

Placement of a posterior costal chondral graft is the mainstay of
management and is a highly effective way of achieving an adequate glottic
airway.
This procedure is best performed through an anterior approach,
traditionally through a complete laryngofissure.
This approach allows excellent exposure of the posterior glottis and direct
visualization of the posterior glottic scar band. The posterior glottis is then
infiltrated with 1% Xylocaine with adrenaline.
The needle is guided through the posterior plate of the cricoid in the
midline until it can be felt to pop through into the space between the
posterior cricoid and the oesophagus. A further small amount of Xylocaine
and adrenaline may then be injected in two or three positions down the
cricoid.
This has the advantage of providing not only haemostasis in the postcricoid
region but also an additional buffer zone between the posterior cricoid
plate and the oesophagus.

The posterior cricoid can then be split vertically for its entire length,
ensuring that the incision is kept completely in the midline.
It is important that the interarytenoid scar band is completely divided.
The incision may be continued superiorly through the interarytenoid
muscles (which are frequently fibrosed) upto the level of the interarytenoid
mucosa itself.
Care must be taken not to inadvertently form a posterior laryngeal cleft.
Following the posterior split, the cricoid should be easily distracted
laterally.
A costal cartilage graft is then harvested and carved so that its height is
approximately the height of the cricoid split and its depth allows the graft
perichondrium to lie reasonably flush with the cut mucosa of the posterior
cricoid.

The graft may be sewn in place with 4.0 Monocryl™ sutures on a P2
needle.
An alternative approach is to form a flanged graft that can be snapped into
place and stabilized with a small amount of fibrin tissue glue.
With the posterior graft in place, the laryngofissure is then closed over an
age-approximate endotracheal tube. If the cricoid does not easily close
anteriorly, a further segment of costal cartilage is used as an anterior
cricoid graft.
A posterior graft rarely needs to be more than 6 mm wide as the primary
aim of surgery is to incise the scar tissue and hold the raw edges apart
while healing takes place.
A graft surpassing this width carries an increased risk of aspiration and a
poor vocal outcome.

This technique can even be used in small children.
Posterior cricoid grafting may be performed as a single or two-stage
procedure. Other variations of open reconstruction include scar
excision alone, buccal mucosal grafting and a posterior cricoid split
without graft placement.
However, a posterior split without a graft normally requires a
considerable period of stenting before full stability is achieved.
A posterior cricoid split without graft placement is most effective in
children younger than 9 months of age, and even then, in a single
stage procedure, usually requires a 10-day period of intubation.

A posterior costal cartilage graft may be placed endoscopically, and
this approach has become increasingly popular over the last 10 years.
Patient selection requires no anterior component of SGS, and a larynx
that can be adequately exposed. The posterior cricoid may be split
with a laser of a sickle knife, and balloon dilation may be used to
distract the posterior split.
Pockets are created behind the posterior plate of the cricoid to
accommodate the posterior flanges of the graft.
Significant force is required to place the graft, and balloon dilation
may assist with graft placement. This technique may be used to
expand the posterior cricoid in posterior glottis stenosis, SGS, or
bilateral vocal cord paralysis.

Other endoscopic techniques may also be efficacious; however, they
are generally not as reliable as the open approach.
Although a laser posterior cordotomy with or without partial
arytenoidectomy is effective, there is a significant chance of
restenosis.
In order to prevent restenosis, the use of mitomycin C is a
consideration, as well as placement of a temporary transglottic stent.
Other described techniques for the endoscopic management of
posterior glottic stenosis include mucosal advancement flaps,
microtrap-door flaps, vocal cord lateralization, and botulinus toxin
(Botox) injections

Whether reconstruction is open or endoscopic, there is a restenosis
rate of 10–20%.
This rate is higher in children who have had thermal injury to the
posterior glottic stenosis. If a child has failed an endoscopic
procedure, then open reconstruction is appropriate.
Conversely, if a child has failed an open procedure, endoscopic
management may be appropriate.
In a recalcitrant airway, it is possible to place a second posterior
costal cartilage graft if required.

POSTR GLOTTIC STENOSIS
Interarytenoid adhesion is a distinct variant of posterior glottic stenosis,
with presentation similar to this condition or to bilateral true vocal cord
paralysis.
An interarytenoid adhesion results from prolonged intubation, when
tongues of granulation tissue lying anterior to the endotracheal tube in the
region of the vocal process unite in the midline to form a fibrous scar band.
While this usually progresses to form posterior glottic stenosis, mucosal
sparing of the posterior commissure sometimes occurs, resulting in the
formation of an interarytenoid scar band
Endoscopic evaluation confirms a small posterior commissure air passage
and a larger anterior glottic airway passage.

However, there may be a marked limitation to the size of
endotracheal tube that can be used for intubation if there is not a
tracheotomy tube already present.
Endoscopic resolution of this problem is simple and effective.
In most cases, microlaryngeal scissors are used to excise the scar
band, with immediate resolution of symptoms.
In some children, this problem may coexist with either or posterior
glottic stenosis

SUBGLOTTIC RECONSTRUCTION
REPAIR TECHNIQUES
Anterior cricoid split
In the neonate who has failed extubation, the anterior cricoid split procedure is an
alternative to tracheotomy
The criteria for anterior cricoid split are
• failed extubation on at least two occasions
• weight >1500 g
• extubation failure secondary to laryngeal pathology
• no assisted ventilation for 10 days before evaluation
• supplemental O2 requirement <35%
• no congestive heart failure for 1 month prior to evaluation
• no acute upper or lower respiratory tract infection at the time of evaluation
• no antihypertensive medication for 10 days before evaluation.

The procedure involves an anterior incision of the trachea from the
second tracheal ring, up through the cricoid and into the lower third
of the thyroid cartilage, just below the insertion of the anterior
commissure.
The child is then left intubated for 10 days, with the neck wound left
at least partly open to minimize the risk of subcutaneous air build-up.
A thyroid alar interposition graft is a modification that permits earlier
extubation.
Currently, infants requiring intubation and subsequently failing
extubation are far more likely to be affected by extreme prematurity
or to have other genetic or congenital comorbidities and, as a
consequence, success rates for the anterior cricoid split are
significantly lower.

Laryngotracheal reconstruction: anterior cartilage graft
Mild to moderate SGS is well managed with costal cartilage grafting to the
anterior cricoid
The anterior airway is split from the tracheotomy site to the lower aspect
of the thyroid cartilage.
An age-appropriate sized endotracheal tube or suprastomal stent is then
inserted, and a measurement is taken of the size of graft needed to
comfortably close the deficit in the anterior airway.
A costal cartilage graft is then harvested and carved to allow a boat-shaped
and perichondrium-lined insert to distract the anterior cricoid.
An outer flange prevents graft prolapse into the airway. This technique is
also useful for managing suprastomal collapse or narrowing of the upper
trachea.

Laryngotracheal reconstruction: posterior cartilage graft
Costal cartilage grafting of the posterior cricoid for SGS may be
performed in an identical fashion as for posterior glottic stenosis.
If the anterior cricoid can then close comfortably over an appropriate
sized endotracheal tube or stent, the additional anterior grafting is
not required
If the anterior cricoid cannot comfortably close over an appropriately
sized endotracheal tube or stent, then an additional anterior graft is
required, as previously described.
This is necessary for most grade III and all grade IV stenoses.

Cricotracheal resection
Cricotracheal resection (CTR) has an increasing role in the
management of SGS. This procedure requires the removal of the
subglottic scar tissue, with the anastomosis of healthy trachea to a
healthy larynx.
This is a technically more challenging operation than laryngotracheal
reconstruction with cartilage grafts
CTR with primary anastomosis is a safe and effective procedure for
the treatment of severe SGS in infants and children.

Diagnostic precision is essential, operative timing should be judged
carefully, and operative technique must be precise.
The reasons for the high success rate include the complete resection
of the stenotic segment with restoration of a lumen using a normal
tracheal ring, the preservation of normal laryngotracheal support
structures without disruption of the cartilaginous framework, and full
mucosal lining on both sides of the anastomosis, thus minimizing or
preventing granulation tissue and restenosis.

COMPLICATIONS OF CTR
Injury to the recurrent laryngeal nerve
Dehiscence of the anastomosis. This is most likely to happen if the
operative site gets infected or if there is tension at the site of the
anastomosis, or because of forceful reintubation if the endotracheal
tube becomes dislodged.
If granulation tissue is allowed to grow, there is also a risk of
restenosis.
For this reason, sutures through the cartilage should emerge
submucosally at the edge of the anastomosis.

Experimental data in primates show that when CTR and primary
tracheal anastomosis are performed with a good initial result, the
thyroid cartilage and tracheal ring sutured together continue to grow
normally.
A further advantage of the CTR technique may be that voice quality
should not deteriorate because the anterior commissure of the
larynx is maintained in its initial position and there is no widening of
the larynx posteriorly with an interposition graft.
However, in older children, CTR may limit the ability to tilt the thyroid
cartilage on the cricoid cartilage, in turn restricting cord tensioning
and leading to a loss of vocal range.

Slide tracheoplasty
The slide tracheoplasty was originally conceived as an operation to expand
a congenitally stenotic trachea due to complete tracheal rings and is
currently the operation of choice for the management of complete
tracheal rings.
It is a versatile operation and may also be employed for patients with
acquired laryngotracheal stenosis.
Although originally described using an intrathoracic approach, a cervical
approach allows access to the upper two-thirds of the trachea.
For patients with combined disease, if the associated SGS makes a graft to
the anterior cricoid an option, then the lower trachea may be slid into the
split anterior cricoid as an alternative to a costal cartilage graft.

The technique involves adequate exposure of the larynx and trachea, with
the stenotic segment then being delineated by an assistant performing
bronchoscopy (rigid or flexible) while the surgeon places a 30G needle into
the airway.
The proximal and distal aspects of the stenosis are marked on the anterior
airway, and the length of the stenosis is measured.
The trachea is then transected, typically with a bevelled transection
commencing on the anterior trachea proximal to the midpoint of the
stenosis, and extending over two rings distally, with the posterior
transection point being at or just distal to the midpoint of the stenosis.
The distal trachea is then split in the midline posteriorly to just beyond the
stenosis, while the proximal trachea is split anteriorly to just beyond the
stenosis – typically to thyroid cartilage.

The most damaged and stenotic segment of trachea tends to lie at the
midpoint of the stenosis, and this may be resected if desired.
The trachea is then anastomosed with a double-armed PDS suture,
typically a 4.0, with RB-1 needles in an older child or adult.
A running suture technique is employed, with no attempt to keep the
suture extraluminal but with care taken to tighten the running suture as
the anastomosis is completed.
A single proximal anterior knot completes the anastomosis. The airway is
leak-tested and then sealed with fibrin glue, and the patient is typically
extubated at the end of the procedure.
While it is feasible to perform a slide tracheoplasty into the posterior
cricoid, it is technically challenging, and the results are unpredictable.
Because of this, it is not recommended.

CONTRAINDICATIONS
All contraindications to airway reconstruction are relative. Usually, airway
reconstruction is not attempted unless decannulation is the goal.
Gastro-oesophageal reflux disease and eosinophilic oesophagitis should be
controlled pre-operatively, and pulmonary function optimized.
Operating on a child requiring pulmonary pressure support to ventilate
adequately is unwise. Single-stage reconstruction is inadvisable in a child who is
difficult to intubate.
In children with a history of sedation problems, past failure of airway
reconstruction or multiple levels of airway pathology, single-stage reconstruction
should be approached with caution.
In children undergoing CTR, the risk of anastomotic dehiscence seems higher in
the presence of Down syndrome, MRSA or a past history of distal tracheal
surgery.
The greatest disservice to a child is for airway reconstruction to cause or
exacerbate ongoing aspiration

COMPLICATIONS
Complications may be subdivided into intra-operative, early post-operative and late post-
operative.
Intraoperative complications include bleeding, pneumothoraxand loss of the airway with
resultant hypoxia. Early post-operative complications include infection, air leakage from
the operative site, dehiscence of an anastomosis and loss of a graft.
The risk of air leakage and graft loss is highest when systemic steroid use is continued
beyond two or three peri-extubation doses.
With single-stage procedures there is a risk of accidental extubation and risks associated
with paralysis or sedation.
Extubation may be compromised because of glottic oedema and granulation caused by
the endotracheal tube.
The most significant long-term complication is failure of the reconstruction with
restenosis of the subglottis, with an incidence between 10% and 20% in most series.

Revision airway surgery/the recalcitrant airway
Failure of laryngotracheal reconstruction or CTR does not preclude
further attempts at reconstruction but it may complicate further
reconstructive efforts.
In revision airway surgery, particular care should be taken to optimize
the outcome by careful pre-operative evaluation of the patient and
their airway.
Failed expansion cartilage grafting may still be amenable to either
further cartilage grafting or resection, while failed resection may still
be amenable to further resection or cartilage grafting.

Acquired laryngotracheal stenosis

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