Keywords
airway stenosis - inspiratory stridor - laryngeal malformation - airway surgery - tracheal reconstruction - laryngeal reconstruction
1. Clinical anatomy
The term “laryngotracheal junction” originates from the clinical observation of some
of the peculiarities that this section of the upper airway shows, which is only a
few centimeters long. Anatomically, it is the zone that begins cranially at the
inferior border of the subglottic shelf of both vocal folds and extends over the
cricoid cartilage to the first tracheal rings. The caudal boundary is not clearly
defined. This area takes on special significance as a predilection site for some
clinical pictures that either predominantly or even exclusively occur here. These
include infantile “pseudocroup” in acute viral infections, true croup in the setting
of diphtheria, respiratory manifestations of granulomatosis with polyangiitis
(formerly Wegener’s disease), idiopathic progressive subglottic stenosis, and the
numerically particularly significant scarred subglottic stenosis, such as after
long-term intubation, tracheostomy, or caused by other trauma. The laryngotracheal
junction thus describes the actual subglottis and the beginning of the cranial
trachea as a biologically homogeneous but anatomically heterogeneous unit. The
submucosal tissue on the cricoid plate seems to be of special importance. The
cricoid has the anatomical peculiarity of being the only section in the airway to be
completely cartilaginous over the entire circumference. Contrary to its name, the
cricoid cartilage is usually elliptically shaped. Dorsally, it forms the articular
surfaces for the arytenoid cartilage and thus supports the dorsal glottis. It is
elastically connected to the thyroid cartilage via the cricothyroid membrane; by
means of contraction of the cricothyroid muscles, the only laryngeal muscle
innervated by the superior laryngeus muscle, it tilts the arytenoid cartilages
dorsally and thus pretensions the vocal folds (frame tension). At the level of the
cranial cricoid cartilage, the recurrent nerve leaves its sulcus between the trachea
and the esophagus and, after branching in a number of different ways, moves to the
back of the cricoid cartilage plate in order to reach the interior of the larynx via
its cranial edge.
2. Diagnostics
The leading symptom of laryngotracheal junction disease is inspiratory stridor.
However, it is not possible to draw any further conclusions about the type and
extent of the stenosis auditorily. Simple indirect laryngoscopy often misses
subglottic changes, and transnasal flexible endoscopy offers greater diagnostic
certainty. Nevertheless, despite typical symptoms, the correct diagnosis is
surprisingly often made rather late; the misdiagnosis of bronchial asthma, in
particular, is not uncommon. The most reliable diagnostic measure is endoscopic
examination under short anesthesia with the aid of rigid optics or surgical
microscope. Only in this way can all details be comprehensively identified and taken
into account. Another advantage is the possibility of palpatory examination or
manipulation. Preoperative diagnostic endoscopy is the most important measure for
correct diagnosis and, consequently, for correct selection of the therapeutic
procedure. Its importance, as well as the importance of precise, accurate and
reproducible execution, can therefore hardly be overestimated.
The simplest and often most sufficient technique is brief inspection in apnea. In
more complex situations or simultaneous interventions, jet ventilation should be
preferred as a reliable and cost-effective procedure. Alternatively, intermittent
intubation with a thin tube is possible. In this case, care should be taken to
perform a primary endoscopy before the first intubation to avoid tube-related
changes that may thwart an accurate diagnosis. Provided airway stenosis is
investigated with some regularity, more advanced ventilation techniques should be
available to safely manage even highly complex ventilation situations. These include
tubeless supraglottic interposed simultaneous high- and low-frequency jet
ventilation, apnea oxygenation with high-flow oxygen, and the Ventrain system.
Specially adapted jet ventilation devices ensure good oxygenation over longer
periods even in very young children and neonates.
The patient is positioned in the same way as for microlaryngoscopy: with the head
extended and the neck flexed (sniffing position). The often observed simultaneous
extension of the neck and support of the shoulder area with a positioning pillow
should be avoided, as they complicate the exposure of the larynx [7].
The anesthesiologist’s spatula laryngoscope is used to expose the larynx, and
visualization is performed with a 0° optic of 30 cm length, correspondingly shorter
in children. Routine video projection and recording is highly recommended. It allows
all participants to be informed simultaneously about the current examination and
thus about any risk situations. The interdisciplinary discussion of the case on the
basis of the recorded high-resolution videos is extremely helpful for exact
diagnostics and therapy planning.
After optimizing the image parameters and aspirating secretions, a slow camera
movement is carried out from supraglottic to carina and back. The topographic
relation of the pathology can be reliably established by markings on the endoscope
via a fixed point (row of teeth).
Assessment of airway stenosis should follow a structured and reproducible procedure.
The most important parameters here are severity of stenosis, stenosis length,
involvement of cricoid cartilage and vocal fold level, consistency and degree of
activity. A recent consensus paper from the ELS provides a good guide for the
evaluation of airway stenosis [17]. Based on
the Cotton-Myer classification, an ELS classification was created that is easy to
use and memorize ([Table 1]), yet provides
more information and higher prognostic value [27].
Table. 1 Classification of an airway stenosis according to the
European Laryngological Society (ELS). Sub-locations.
Supraglottic/glottis/subglottic/tracheal. The sum of the sub-locations
is given with a letter (a=1 location, b=2 locations etc.). Comorbidity:
the presence of cardiopulmonary concomitant diseases is coded with “+”.
Example: an isolated subglottic stenosis with 60% obstruction in a
patient with COPD corresponds to grade IIIa+.
|
Grade I
|
Grade II
|
Grade III
|
Grade IV
|
|
<50% Narrowing of the cross-sectional area
|
50–70% Narrowing of the cross-sectional area
|
70–99% Narrowing of the cross-sectional area
|
Complete atresia
|
|
Number of sub-localizations
|
Number of sub-localizations
|
Number of sub-localizations
|
Number of sub-localizations
|
|
comorbidity
|
comorbidity
|
comorbidity
|
comorbidity
|
In adults, thin-slice computed tomography (with contrast enhancement if necessary) is
the primary imaging modality, especially for stenoses of the laryngotracheal
junction. Special attention is given to changes in the cricoid cartilage and cricoid
plate. Magnetic resonance imaging is often good at visualizing the near
pathognomonic submucosal soft tissue thickening in progressive idiopathic subglottic
stenosis. Three-dimensional reconstructions may facilitate rapid assessment of the
topography of the stenosis.
In infancy and especially toddlerhood, on the other hand, imaging techniques are only
of importance for special questions due to the weak contrast between cartilage
structures and surrounding soft tissue.
3. Airway stenosis in adults
3. Airway stenosis in adults
3.1 Intubation-related stenosis
In adults, the development of tracheal stenosis by intubation is a rare event
([Video. 1]). In addition to the
duration of tube insertion [20], any
intubation trauma is of particular importance, as it may occur especially in
emergency situations. The underlying pathomechanism has not been conclusively
clarified, but a multifactorial genesis can be suspected. Additional risk
factors are an individual disposition and esophago-laryngeal reflux.
Differentiation, especially from idiopathic subglottic stenosis, can be
difficult. As a basic rule, if there is a time interval of more than 2 years
between intubation and the first appearance of symptoms, a connection must be
considered unlikely. Typically, intubation-associated stenosis manifests at the
level of the cricoid cartilage and is short-stretched. In the early stage of
stenosis formation, before completion of complete scarring, endoscopic therapy
may be successful.
3.2 Idiopathic progressive subglottic stenosis (IPSS)
IPSS affects almost exclusively women of childbearing age ([Video. 2]). The symptomatology of
inspiratory stridor usually develops over years, but accelerated courses are
possible [29]. A precipitating event must
be ruled out by careful history taking; intubation more than 2 years ago may be
considered etiologically insignificant. Particular attention should be paid to
exclusion of systemic disease, especially polyangiitis with granulomatosis
(Wegener's disease). Accelerated disease progression is typical during
pregnancy. In combination with the clear gender predisposition, this has always
been interpreted as an indication of a possible connection with the metabolism
of female sex hormones. Studies to date have been contradictory in this regard,
but recently there has been evidence that an imbalance between different types
of estrogen and progesterone receptors may be etiologically significant, the
importance of which for wound healing has been documented elsewhere [4]
[5]
[6]. The endoscopic
appearance is inconsistent, but always shows an inconspicuous epithelial
surface, mostly with submucosal, corkscrew-like scar strands. Almost
pathognomonic is an increase of submucosal tissue especially in the area of the
cricoid cartilage plate, which cannot be explained nosologically. Numerous
etiologic models are discussed in the literature, ranging from esophagotracheal
reflux to microtrauma due to coughing attacks to chronic mycoplasma infections
[3]
[8]
[9]. However, none of these
explanatory models can plausibly explain the clinical presentation, the course
of the disease, and especially the sex distribution. Proposals for therapy are
correspondingly inconsistent. Some authors interpret IPSS as fibrotic
inflammation in the sense of a limited or localized systemic disease, from which
it is concluded that surgical repair does not adequately address the
pathophysiologic processes. However, the application of endoscopic procedures,
usually consisting of laser-based interventions, possibly in combination with
high-pressure balloon dilatation as well as intralesional injections with
corticosteroids, show rather disappointing results in many series with, in
particular, high treatment frequency with only short symptom-free intervals
[19]
[23].
Open surgical reconstruction aims to remove the zones of pathology as completely
as possible. The procedure of choice is cricotracheal resection (CTR, see
section on surgical procedures) – corresponding data in the literature show
predominantly good to very good results [1]
[2]
[10]. On the other hand, however, it is more
time-consuming and the risk of complications should not be underestimated,
especially in this patient group, which is distinguished from other forms of
stenosis by a higher tendency to re-stenosis.
3.3 Tracheostomy
The most common form of tracheostomy-associated tracheal stenosis is the
so-called “A-frame” deformity ([Video.
3]). The cause is a loss of tracheal anterior wall as it develops
iatrogenically due to an overly generous resection (especially with a necrotized
Björk flap) or after perioperative infection with subsequent necrosis. The lack
of anterior wall stability leads to instability of the tracheal sidewalls, which
then medialize in the shape of the letter A. The apt term “pseudoglottic”
stenosis has also been coined for this condition. Another significant risk
factor is injury to the cricoid during tracheostomy, leading to chronic
perichondritis with subsequent stenosis. Depending on the individual situation,
other patterns of injury are of course encountered. The initially suspected
higher frequency of laryngotracheal stenosis after dilated puncture tracheotomy
cannot be verified neither statistically nor by our own observations [14].
3.4 Systemic diseases
In the majority of cases, the diagnosis of systemic diseases can be confirmed by
a detailed history or by the presence of other manifestations. In particular,
polyangiitis with granulomatosis may result in a larval initial finding in the
subglottic larynx [28]. Endoscopic
diagnosis shows a typical picture in most cases, whereas both biopsies and
serological parameters may not always provide clarity, especially in the early
phase. To clarify idiopathic subglottic stenosis, which can be difficult to
differentiate from larval systemic diseases, a complete diagnosis in the sense
of an exclusion procedure is obligatory.
4. Airway stenoses in pediatric patients
4. Airway stenoses in pediatric patients
4.1 Subglottic stenoses
The cricoid cartilage is the only section in the airway that is completely
cartilaginous and already physiologically has the smallest cross-section.
Together with numerous other factors, this makes the cricoid a predilection site
for the development of stenoses. Accordingly, the largest number of all acquired
and congenital clinical pictures that can lead to a narrowing of the lumen are
found here. Intubation-associated lesions remain by far the largest group.
In perinatal medicine, the avoidance of a tracheostoma is a high objective.
Unlike in adult intensive care, longer intubation times are also acceptable for
this purpose. This is not only based on the understandable desire to avoid
additional traumatization and stigmatization of the child and the relatives.
Rather, neonatologists are aware that an early tracheostomy poses a considerable
risk to the child. This is true not only for the surgical procedure itself,
which is technically quite different from procedures performed at older ages and
is challenging even for a skilled surgeon. For even after successful creation
and healing of a tracheostoma, a significant risk remains: The combination of
small neck dimensions with mostly well-developed subcutaneous adipose tissue and
overall low reserve during apneic episodes leads to a high risk compared to
accidental cannula dislocation. In infants, after removal of the tracheostomy
tube, the tracheostomy canal is immediately functionally occluded by the
surrounding soft tissues of the neck. Not infrequently, this is unnoticed until
the compensatory reserve is already depleted. Therefore, deaths due to
obstruction or dislocation of a cannula in an otherwise irritation-free
tracheostoma occur again and again. Unlike at any other age, the tracheostoma in
infants therefore poses a risk that requires special attention. From this
derives the need for permanent monitoring of respiration. Because of this
increased mortality, the insertion of a tracheostoma at the age of up to 18
months should only be undertaken in the absence of alternatives. This article
presents other, possibly also costly appearing therapy procedures, which should
be intensively applied and exploited in order to come as close as possible to
the goal of tracheostoma avoidance.
4.2 Glottic stenoses
Interarytenoid fibrosis is a typical but widely unknown complication after
intubation. Scarring in the posterior commissure results in mechanical fixation
and/or ankylosis of the arytenoid cartilages. Differentiation from neurogenic
vocal fold arrest is clinically difficult; testing passive mobility of the
arytenoid cartilages during microlaryngoscopy is the diagnostic gold standard
([Video. 4]). Surgical therapy, as
with all glottic stenoses, must aim to achieve the best possible compromise
between voice and breathing. Although tracheostomy largely avoids this dilemma,
it is mostly perceived as unacceptable, so some voice deterioration is accepted
as the price of tracheostomy avoidance. Numerous individual factors determine
the choice of surgical approach; in most cases, at least a subtotal
arytenoidectomy is required. If this is not sufficient, an expansion of the
cricoid cartilage plate in the sense of a posterior laryngotracheal
reconstruction (LTR, see section on Surgical Procedures) must be performed. Only
in carefully selected cases of mild interarytenoid fibrosis surgical scar
separation by laser division alone can be sufficient, but this must then always
be combined with passive laterofixation.
4.3. Supraglottic stenoses
4.3. Supraglottic stenoses
4.3.1 Laryngomalacia
The most common cause of stridor in newborns is changes in the supraglottis
leading to a tendency to collapse on inspiration. The term laryngomalacia has
become accepted as a generic term describing the functional interaction of
immaturity of the juvenile larynx resulting in instability of the epiglottis and
relative hypertrophy of the mucosa in the region of the arytenoid cartilages.
There is also usually a shortening of the aryepiglottic folds in the sense of a
discrete malformation. The unstable epiglottis and hypertrophic mucosa of the
arytenoid cartilages can be sucked into the glottis by the flow of respiratory
air ([Video. 5]).
Laryngomalacia is found to be the primary cause in up to 60% of infants with
stridor. The stridorous breathing sound typically begins on the day of birth or
a few days later. The worsening of symptoms is particularly noticeable with
exertion, such as drinking or crying. The voice is completely unaffected. The
breathing sound may be position-dependent and usually decreases in a prone
position. Inspiratory stridor, which is usually low frequency, usually increases
during the first months of life and reaches a maximum 3 to 6 months after birth
if untreated. As the child grows, there is usually a spontaneous improvement in
the breath sound, so that in more than 90% of cases there are no longer any
abnormalities after the 18th month of life. However, in approximately
10% of cases, chronic airway obstruction can lead to apneas, impaired feeding
with failure to thrive, weight loss, and pulmonary distress. This severe form of
laryngomalacia requires further evaluation to consider possible surgical
treatment options. However, milder forms may also be an indication for minimally
invasive therapy, especially if the parents are constantly concerned about the
breath sounds they perceive as threatening.
The different forms of laryngomalacia have found expression in numerous
classifications. The generic term supraglottoplasty covers all measures to
stabilize the laryngeal entrance. The cutting of the mostly shortened
aryepiglottic folds leads to a reduced tendency to prolapse in the direction of
the glottis due to the natural elasticity of the epiglottis. In cases of mucosal
hypertrophy in the region of the cartilagines cuneiforme and corniculata, their
reduction is indicated with strict sparing of the posterior commissure. In rare
cases, it is necessary to “trim” the epiglottis by means of reduction of the
mucosa at its free edges.
Supraglottoplasty ([Video. 6]) is a
reproducible procedure of manageable difficulty. Optimal exposure and maximum
tissue-conserving technique are essential. Complications can only occur if the
procedure is too aggressive. The local tissue reaction remains so low that
extubation is possible immediately after the procedure. The occurrence of
dysphagia is rarely observed and then only transitory.
The most serious complication is the development of supraglottic stenosis due to
excessive scarring. The best prophylaxis consists of restrained mucosal
resection and meticulous protection of the posterior commissure.
The high success rates of more than 95%, the minimal invasiveness, and the
possibility of simultaneous performance during diagnostic endoscopy make
supraglottoplasty an elegant and effective procedure that should be indicated at
a low threshold.
5. Malformations
5.1 Glottic web
Congenital “web” describes a congenital synechia of both vocal folds, typically
affecting the ligamentous portions of the glottis. The diagnosis is usually
obvious endoscopically, but less pronounced findings are not infrequently missed
on flexible endoscopy because the vocal folds appear to be passively attached to
each other. Although it usually appears as a delicate and short-stretched
membrane, it is a complex malformation of varying extent that always reaches the
cricoid cartilage anterocaudally ([Video.
7]). Therapy depends on the extent of the finding: if the glottic
stenosis is respiratory, normalization of breathing is the primary goal. In the
long term, however, the goal of minimally disrupted voice production must be
considered. Therefore, transection or even piercing alone is not adequate and
should be used only in an emergency. Inadequate sole transection of the membrane
may lead to an increase of stenosis up to complete atresia of the glottis. The
treatment of choice is endoscopic separation of the synechia with passive
insertion of a placeholder. Tracheostomy, even transitory, should be avoided.
This procedure is readily available when the patient weighs about 10kg or more.
Up to this point, a transitory glottic dilatation may be useful. Primary
definitive reconstruction is only indicated in individual cases of simultaneous
laryngeal malformations, especially subglottic stenosis.
5.2 Congenital vocal fold immobility
Congenital bilateral vocal fold immobility is probably neurogenic in origin. A
precise pathophysiologic explanation is not known. The position of the immobile
vocal folds may vary widely and provide for different clinical distress in the
children.
Even for the experienced examiner, assessment of vocal fold mobility in the
newborn can be very difficult and represents one of the few clear indications
for flexible endoscopy in the awake infant. Co-manifestation of vocal fold
immobility and laryngomalacia occurs regularly. Therefore, when evaluating
stridor in laryngomalacia, the mobility of the vocal folds should be
assessed.
Electromyography is not useful at this age.
The spontaneous onset of glottic motility has been described and demonstrated
several times in our own patients. Therefore, ablative glottic dilatations
should not be considered until after 12 months of age. Up to this time,
depending on the clinical symptoms, the insertion of a tracheostoma may be
unavoidable, although this is associated with a considerable morbidity,
especially in this age group. In individual cases, a transitory lateralization
of a vocal fold by means of a traction cord can improve respiration and help to
avoid placing a tracheostoma.
5.3 Congenital subglottic stenosis
Genuine hypoplasia of the cricoid cartilage results in a reduced diameter which,
depending on its severity, can lead to primary obstruction of the
newborn's breathing. If this obstruction leads to emergency intubation
of the infant after birth, the stenosis is later almost indistinguishable from
intubation trauma.
Congenital cricoid stenosis is characterized by predominantly inspiratory stridor
occurring immediately postpartum or a few weeks after birth. External causes and
especially intubation are typically not present. For diagnosis, rigid endoscopy
with preserved spontaneous breathing is the tool of choice. This must be done
with special care, as only mild additional mucosal swelling can lead to complete
occlusion of the remaining lumen. Imaging techniques are not helpful in
diagnosis.
If intubation is unavoidable, it should be performed with the thinnest possible
tube and for a short time. Tracheostomy can and should be avoided as much as
possible, since cricoid dilatation is possible immediately after diagnosis. The
gold standard in the treatment of congenital cricoid stenosis is laryngotracheal
reconstruction (LTR-S, see section on surgical procedures) with autologous
thyroid cartilage ([Fig. 1a-c]). This is
also possible in premature infants from 1,000 g birth weight.
Fig. 1 Classification of laryngeal clefts according to Benjamin
and Inglis.
5.4 Dorsal laryngotracheal cleft
A cleft in the dorsal larynx becomes clinically conspicuous with aspiration,
recurrent respiratory infections and failure to thrive [16]. The edges of the clefts passively
attach to each other; palpation of the cricoid cartilage plate with active
spreading of the posterior commissure is crucial for diagnosis; and is only
possible during microlaryngoscopy. Testing for the presence of a laryngeal cleft
should also always be considered during endoscopic diagnosis of esophageal
atresia due to a coincident association of the two [13].
The clinical classification of cleft severity was defined by Benjamin and Inglis
([Fig. 1]) on the basis of anatomic
and prognostic criteria and has proven effective in practice.
More extensive forms with cleft formation beyond the cricoid (type III according
to Benjamin and Inglis) or extending into the intrathoracic trachea (type IV)
usually lead to respiratory insufficiency already in the neonatal period due to
recurrent aspirations and pulmonary infections because of the lack of separation
of esophagus and airway over a long distance. Posterior dislocation of the
endotracheal tube is a typical sign of intubation, which is usually necessary;
often only endoscopic intubation is successful.
Type IV clefts are extremely rare and usually associated with other malformations
or genetically defined syndromes [24].
Reported comorbidities include prematurity, other tracheo-bronchial
malformations, microgastria, and various gastrointestinal or cardiac
malformations in addition to neurological impairments [24]. These require a multidisciplinary
diagnostic and therapeutic approach that usually includes, among many other
things, tracheostomy and chronic home mechanical ventilation and percutaneous
tube feeding usually via PEJ over the first years of life. However, the severity
of other tracheobronchial malformations as well as comorbidities in other organ
systems should be meticulously analyzed before a decision for surgical therapy
is made ab initio.
Mild forms (grades I and II according to Benjamin and Inglis) can be approached
endoscopically ([Video. 10]). If the
entire cricoid cartilage plate is affected (grade III), open reconstruction via
laryngofissure offers much higher chances of success. Surgical reconstruction of
low-grade laryngeal fissures is performed immediately after diagnosis regardless
of age if there are no other contraindications (e. g., low body weight in
premature infants).
Neonates with type IV clefts require initial intensive care stabilization and
sequential therapeutic approach based on clinical tolerance and stability. The
historical mortality of more than 90% could be reduced to less than 20% in
specialized centers. Tracheostoma and surgical correction of at least the
intrathoracic tracheal portion of the fissure to secure the tracheal cannula
position, as well as the creation of a gastrostoma with jejunal limb, are first
emergency measures. These procedures require the use of a heart-lung machine or
ECMO, for which a certain body weight must first be achieved. Surgical closure
of the laryngeal fissure is performed in a further step usually about 2 to 3
months later depending on the clinical course.
6. Neoplasms
6.1 Hemangiomas
The congenital neoplasms are predominantly hemangiomas, which occur
preferentially in the subglottis. Laser surgical therapy of connatal hemangiomas
([Video. 8]) in the airway, which was
frequently indicated in the past, has now been completely superseded by drug
therapy with propanolol. The clinical appearance of subglottic hemangiomas is
often relatively nonspecific and thus difficult to distinguish from other
lesions. Because of the localization, sampling is prohibited. Therefore, in case
of clinical suspicion, probatory weight-adapted drug treatment with a
beta-blocker is the therapy of choice. If the suspicion is correct, an initial
improvement can be expected within a few days. In the few cases that do not
respond to conservative therapy, the reconstructive surgical options described
in the following sections can be applied.
6.2 Cysts of the Morgagni recess/laryngoceles
An outpouching of the Morgagni recess between the vocal fold and the false vocal
fold can assume considerable proportions and lead to obstruction of the airway.
Such an outpouching is encapsulated in the sense of a cyst in infancy. Therapy
in most cases involves marsupialization of the cyst. This is usually adequately
drained thereafter.
6.3 Subglottic cysts
Subglottic cysts are presumably degenerative, distended mucosal glands that may
typically occur in the laryngotracheal junction in premature infants ([Fig. 2]). These are singular but can also
be found in several locations and can cause significant respiratory obstruction
if they increase in size. Therapy includes marsupialization and, if necessary,
balloon dilatation of the lumen in the affected area. Because these are usually
very young infants, collaboration between anesthesiologists and
otolaryngologists during the procedure can be very challenging.
Fig. 2 Subglottic cysts in a former premature infant.
6.4 Papillomatosis
Juvenile papillomatosis of the upper respiratory tract is a relatively rare
disease, but should always be considered in the differential diagnosis of
stridor in infancy ([Video. 9]). Due to
the complexity of the clinical picture, it cannot be presented in depth within
the scope of this paper.
7. Surgical procedures
7.1 Endoscopic therapy options in airway stenoses
Endoscopic therapy procedures have the great advantage that they can be directly
followed by the diagnostic steps. Another advantage is the lower morbidity
compared to open surgical procedures.
On the other hand, they are particularly challenging for the entire
interdisciplinary team, especially with regard to airway management. In the case
of very young children or high-risk interventions, very closely coordinated
cooperation between anesthesiologists and surgeons is therefore indispensable.
This includes precise planning, including the postoperative phase, of the
treatment and video-based presentation to the entire team in the operating
room.
7.2 High-pressure balloon dilation
In this procedure, high-pressure balloons are applied and inflated at the level
of the stenosis during direct (micro)laryngoscopy ([Video. 11]). The products available on the
market serve a very narrow therapeutic niche and are correspondingly expensive.
The characteristics of the various balloons are defined by their approvals and
are offered in different sizes and pressures.
The procedure is technically simple and low-risk. Compared to classical
bougienage techniques, the success rate is much higher because balloon
dilatation involves an eccentric, radial application of force, which avoids
tangential shear forces. Therefore, balloon dilatation is considered a
low-threshold initial procedure with a wide range of indications [32]. As a basic rule, the fresher the
stenosis, the better the results ([Video.
12]). Prior to dilatation, targeted incision of circular scars to
improve scar destruction may be helpful.
In the case of completely scarred stenoses, dilatation alone is unsuccessful.
However, balloon dilatation has also established itself as an adjuvant measure
after open reconstructions, because it is excellent for squeezing out
postoperative edema and for stopping incipient restenosis at an early stage.
Lateral displacement of a vocal fold/laterofixation
Bilateral vocal fold obstruction may be congenital or acquired.
Congenital immobility is highly variable in clinical expression, depending on the
position of the immobile vocal folds. Treatment is required when the general
development of the child is impaired. In principle, the onset of mobility of the
vocal folds can be expected in the course of the first years of life. Since the
individual spontaneous improvement tendency cannot be predicted, the
aggressiveness of therapy is based on the child's distress.
Acquired glottic immobility may be the result of surgical procedures on the heart
or esophagus. The cause of the immobility is trauma to the neural supply and,
depending on its extent, may be irreparable. In these cases, permanent
endoscopic glottic dilation may be necessary.
Passive lateralization can help gain time and avoid a tracheostomy if spontaneous
improvement could be expected.
Lateralization of one vocal fold is performed under endoscopic or microscopic
control by means of a thread looped around the vocal process. It is pulled
through laterally and either tied to the skin via a silicone button or hidden
subcutaneously. In permanent ablative glottic dilation, part of the dorsal
glottis of the affected side is resected by laser surgery prior to
lateralization.
7.3 Use of laser
The use of different laser techniques for the treatment of stenosis in children
has been discussed intensively and controversially in the past. In the meantime,
all major centers agree that the role of lasers in the pediatric airway is very
limited. It is true that with careful indication and technically accurate
application, low-grade subglottic stenoses can often be treated successfully.
However, this is contrasted by a high recurrence rate, which should in no case
lead to repeated laser surgery, as otherwise structural changes in the
surrounding cartilage are induced, leading to an increase in the degree of
stenosis as well as in the length of the stenosis. In the worst case, the
chances of success for open reconstruction are severely compromised. Therefore,
in case of restenosis after laser treatment, an open procedure should be used
for recurrent treatment. In the past, a variety of laser types were propagated,
but the broadest experience and best results were achieved with the
CO2 laser, which has the least thermal concomitant damage and is
particularly precise to use.
The use of a CO2 laser is typically carried out by means of coupling
to the optical system of a surgical microscope. The use via an optical fiber
does not provide any additional advantages and may only appear useful in
individual cases. The advantages lie in the bloodless and contact-free
procedure, which allows the resection of certain areas very precisely. Typical
applications include arythenoidectomy or ablative procedures for glottis
dilation. Supraglottoplasty can also be performed using CO2 lasers
([Video. 6]).
In infants, laser use is limited by the requirement to protect the ventilation
tube. The risk of tube burn should not be underestimated. This risk can be
eliminated by using jet ventilation.
Use of a “shaver”
The so-called "shaver" is an oscillating knife specially
developed for airway surgery with simultaneous aspiration. It sucks in soft
tissue and simultaneously cuts it off in a minimally invasive manner. The
"shaver" is very useful in the removal of small changes in the
mucosa, such as in papillomatosis, and allows fine work under endoscopic
control.
8. Open reconstruction of airway stenoses
Until the 1970s, the cricoid cartilage of the larynx was considered a
"no-man's land" that should be avoided surgically.
During the great diphtheria epidemics of the late 19th century it was
observed that even mild affections of the laryngotracheal junction could cause
high-grade airway stenosis, which could almost never be successfully
reconstructed with the means of the time. Furthermore, the cricoid cartilage was
apostrophized as the foundation of the larynx, which to weaken was associated
with a high risk of permanent laryngeal stability. In addition, the risk of
damaging the recurrent laryngeal nerves was considered to be almost inevitable
with procedures on the cricoid cartilage plate. In children, surgery on the
cricoid cartilage was not ventured until the early 1990s, the prevailing opinion
being that the risk of growth disturbance was high.
Basically, two different surgical strategies can be distinguished for
interventions at the laryngotracheal junction.
Ablating procedures ("resection") aim to completely remove the
pathology and reconstruct the airway through an end-to-end anastomosis. They are
technically demanding and have a serious potential for complications. In return,
they offer significantly superior success rates over all other techniques and
are usually feasible on a single-stage basis. Ideally, they allow simultaneous
resection of a preexisting tracheostoma.
Augmentative procedures ("reconstruction") leave the
stenosis-forming tissue in place and aim to dilate it by inserting cartilage
grafts, mostly from the rib. They are less complex technically and offer a
broader range of indications, but produce poorer results compared with resecting
procedures. They are typically performed 2-staged, i. e., with the tracheostoma
in place, which increases the patient burden but reduces the risk to the airway.
By leaving the tracheostoma in place, this procedure allows a newly created
lumen of the larynx, e. g., in case of atresia, to be splinted by a stent for a
longer period of time.
In individual cases, a combination of the above strategies in the sense of an
extended reconstruction of the airway may also be necessary.
The introduction of high-pressure balloon dilatation in recent years has further
improved postoperative follow-up after airway reconstructive surgery and thus
the chances of success, because it allows gentle treatment of incipient
restenosis or postoperative scarring even in a fresh anastomotic scar.
8.1 Cricotracheal resection (CTR)
For laryngotracheal stenoses with involvement of the cricoid cartilage but
without affection of the glottic level, cricotracheal resection is the procedure
of choice. This is true regardless of the underlying etiology and extent of
pathology. Cricotracheal resection (CTR) was first described for adult patients
almost simultaneously and independently by Pearson [21] and Grillo [11], but its translation to the pediatric
population did not occur until the late 1980s by Monnier [18].
The basic principle is complete resection of the laryngotracheal stenosis ([Fig. 3]) including the cricoid arch with
complete exposure ([Fig. 4]) of the
cricoid plate [31]. After appropriate
mobilization maneuvers, the distal trachea is partially adapted to the remaining
cricoid, predominantly to the thyroid ([Fig.
5]) (thyrotracheal anastomosis). A preexisting tracheostoma is usually
included in the resection unless 2–3 healthy tracheal cartilage rings remain
between the caudal stenotic margin and the cranial tracheostomal margin, which
are available for anastomosis. As a rule, the procedure is performed in a single
stage, i. e. without a new tracheostomy.
Fig. 3 Principle of cricotracheal resection (CTR). The stenosis of
the laryngo-tracheal junction is exposed and mobilized under
preservation of the nerves. Source: Created by S. Burger on behalf of
the Klinikum Stuttgart
Fig. 4 Principle of cricotracheal resection (CTR). The stenosis of
the laryngo-tracheal junction is resected completely under preservation
of the dorsal plate of the cricoid cartilage. Source: Created by S.
Burger on behalf of the Klinikum Stuttgart
Fig. 5 Principle of cricotracheal resection (CTR). The trachea is
mobilized and anastomosed into the preserved laryngeal structure.
Source: Created by S. Burger on behalf of the Klinikum Stuttgart
Whenever possible, ventilation is initially performed via a laryngeal mask. The
cricoid, thyroid and trachea are carefully exposed via a cervical approach.
Depending on the expected length of the resection, a supralaryngeal release is
performed by incising off the infrahyoid muscles. Dissection of the lateral
trachea is performed strictly along the cartilage, reliably avoiding damage to
the recurrent nerves. The use of surgical loupes is highly recommended,
especially for this substep. Below the stenosis, the trachea is incised and the
distal tracheal stump is intubated. The cranial incision is made in the membrana
cricothyroidea, the cricoid cartilage arch is transected obliquely on both sides
([Fig. 6]), and the mucosa on the
cricoid cartilage plate is incised depending on the level of the stenosis. The
cricoid cartilage plate is exposed to its caudal edge, and the stenotic segment
is separated from the esophagus and resected in toto ([Fig. 7]). Complete resection of the entire
pathologic portion is of high importance, as is generous mediastinal
mobilization of the distal trachea. The diamond drill is used to thin out the
cricoid cartilage plate to remove any residual pathology as well as to gain
additional space ([Fig. 8]). The distal
trachea is now placed tension-free on the cricoid cartilage plate and
anastomosed with absorbable suture material to the lateral aspects of the
cricoid, the mucosa of the interarytenoid region, and the thyroid ([Fig. 9]). This creates a primary
epithelialized anastomosis while avoiding exposed cartilaginous surfaces ([Fig. 9]). Prior to final knotting of the
anastomotic anterior wall, the ventilation tube is removed from the distal
trachea and the laryngeal mask still in place is reused for ventilation. The
main advantage here is the immediate check for any air leaks, which must be
meticulously closed. With few exceptions, spontaneous breathing is recovered on
the table, postoperative intubation is of no benefit. Chin-chest sutures make
physiologic breathing difficult and do not provide additional safety for
anastomotic integrity. They should therefore be considered obsolete.
Fig. 6 Intraoperative steps of CTR. Exposition of the cricoid
cartilage.
Fig. 7 Intraoperative steps of CTR. Exposition of the cricoid
cartilage plate after resection of the stenosed area.
Fig. 8 Intraoperative steps of CTR. Beginning of anastomosis
between trachea and larynx, sutures in place, not yet tied
Fig. 9 Intraoperative steps of CTR. End of anastomosis between
trachea and larynx.
The success rate of a technically accurate and correctly indicated CTR is well
over 90%, which has been reproduced by various working groups [12]
[26]
[33]. Nevertheless, this is
a complex, three-dimensional procedure of considerable difficulty that requires
a learning curve that should not be underestimated. Despite the excellent final
results, complications are not uncommon. Minor endoscopic corrections, such as
removal of fibrin layers or granulations, are required in almost 2/3 of all
patients, mostly only once. Severe complications such as anastomotic
insufficiencies or cartilage necrosis are very rare exceptions [22]. Despite the anatomical proximity,
injuries of the recurrent nerves are rare events due to accurate and precise
surgical technique.
8.2 Tracheal segment resection
Tracheal segment resection is the procedure of choice for stenoses of the
cervical and mediastinal trachea without cricoid cartilage involvement, which,
however, occur much less frequently compared to subglottic stenoses. If the
cricoid is involved, segmental resection is a contraindication! The unrecognized
and/or disrespected extension of the pathology into the level of the cricoid
regularly leads to restenosis, if nevertheless a pure segmental resection is
performed instead of the actually indicated CTR. In the narrower sense, this is
not an operation at the laryngotracheal junction, so this surgical technique
will be described only briefly.
Since isolated tracheal stenoses without involvement of the cricoid cartilage are
comparatively rare, but tracheal segment resection as "transverse
resection" is often used as a synonym for tracheal surgery, it can be
assumed that the indication is often made too uncritically. This is probably the
reason why tracheal segment resection has an unjustified reputation as a
procedure with little chance of success. With correct indication and precise
technical implementation, however, the success rates are excellent.
The access route is almost exclusively transcervical, even for stenoses quite
close above the bifurcation. Optimal exposure of the stenotic area with
circumferential preparation of the entire tracheal circumference is essential.
Separation between the esophagus and the pars membranacea is obligatory. Strict
attention must be paid to adequate mobilization of the distal and proximal
trachea to ensure a tension-free anastomosis, depending on the length of the
resection. After complete resection of all pathological parts, the anastomosis
is performed with absorbable suture material (PDS 2.0 or 3.0). Postoperative
intubation should only be performed in absolutely exceptional cases; chin-chest
sutures are obsolete.
8.3 Laryngotracheal reconstruction (LTR)
More than 100 years ago, in the case of diphtheria-related subglottic stenosis,
which was endemic at the time, an attempt was made to achieve dilatation of the
stenosed airway by permanent insertion of a placeholder. The name of Rethy is
associated with the technique of additional splitting of the cricoid cartilage,
by which the splinting dilatation was to be facilitated. In the 1970s, Cotton
first described a technique in which the split of the cricoid cartilage was
fixed anteriorly and posteriorly with an autologous graft of rib cartilage [15]. Under the term laryngotracheal
reconstruction, this procedure represented the gold standard in the treatment of
subglottic and glottic stenosis for the following 3 decades. The introduction of
cricotracheal resection also in children has relativized the importance of the
procedure. However, it remains the procedure of choice for all cases involving
the vocal fold level. Even in cases of higher grade interarytenoid fibrosis that
cannot be treated promisingly by endoscopy, laryngotracheal reconstruction (LTR)
remains the best form of therapy.
Compared with cricotracheal resection, LTR is a technically less complex
procedure that can be learned much more quickly [30]. The possible complications, although not less frequent, are less
dramatic. These are probably also the most important reasons why, especially in
childhood, CTR, which is fundamentally more promising, has only been able to
prevail over laryngotracheal reconstruction in terms of numbers at particularly
specialized centers. Another reason is the increasing number of complex stenoses
involving the glottic level.
Autologous transplantation of rib cartilage is reliably possible in childhood;
with increasing age, wound healing disorders with resorptions or rejections
occur increasingly. Nevertheless, LTR can be a quite reasonable treatment option
until the 4th decade of life, when resecting procedures are not
possible. However, the indication must be made very carefully.
The harvesting of rib cartilage is usually technically feasible after the age of
2. In the first 18 months of life, a special form of LTR with the use of
autologous thyroid cartilage can be performed [25] (see section LTR-S).
There are different modifications for the LTR depending on the author, so only
the basic features will be described here.
The thyroid, cricoid, and cranial trachea are visualized via an external approach
at the level of the cricoid cartilage. Unlike CTR, circumferential preparation
is not required, so there is no significant risk to the recurrent nerves. After
meticulous exposure of the laryngeal structures, the medial incision of the
cricothyroid membrane, the cricoid, and the upper 1–3 tracheal cartilage rings
is made. Depending on the exact location of the stenosis, a partial or even
total laryngofissure must also be performed. For atraumatic exposure, the use of
a special laryngofissure spreader is recommended ([Fig. 10]). After clear exposure of the
cricoid cartilage plate, the incision is made along the entire length until
there is a clear gap between the two halves of the cricoid cartilage. If
necessary, any additional interarytenoid fibrosis present must be separated with
microscissors, preserving a cranial mucosal boundary. The posterior graft is
prepared in a winner’s rostrum-shaped fashion with the "1st
place" facing lumenally, and should remain covered with rib
perichondrium to reduce the tendency for granulation. To accommodate the graft,
the posterior perichondrium of the cricoid cartilage plate is undermined. The
graft is then successfully inserted with significant preload; in the vast
majority of cases, additional fixation by suturing is not necessary or useful.
The inherent tension of the cricoid cartilage results in a primary stable fit of
the rib cartilage ([Fig. 11]). In an
analogous manner, a second graft is inserted into the split cricoid, extending
into the cranial trachea or the caudal thyroid, depending on the individual
situation ([Fig. 12]).
Fig. 10 Surgical retractor developed specifically for the
exposition of laryngeal fissure. The branches are available in different
lengths and may be changed according the anatomical depth. Source:
Richard Wolf GmbH
Fig. 11 Principle of dorsal laryngo-tracheal reconstruction (LTR).
A cartilage graft of the rib is inserted in the split cricoid cartilage
plate. The exposition is most successful by means of the specifically
developed laryngeal fissure retractor. Source: Created by S. Burger on
behalf of the Klinikum Stuttgart
Fig. 12 Principle of anterior laryngo-tracheal reconstruction
(LTR). A cartilage graft of the rib is inserted frontally in the split
cricoid cartilage. Source: Created by S. Burger on behalf of the
Klinikum Stuttgart
LTR is a modular procedure that can also be used anteriorly only or posteriorly
only. Anterior LTR alone does not require stenting and can usually be performed
without a tracheostomy. Posterior LTR and combined anterior and posterior LTR,
on the other hand, should usually be performed in two stages, i. e., with
temporary tracheostomy or preservation of an existing tracheostoma.
Postoperative stenting to splint the reconstructive result is used with
increasing restraint. The Montgomery T-tube not infrequently leads to
considerable problems due to granulation formation and pressure lesions. The
"LT mold" developed by Monnier represents a considerable
improvement in all respects, but unfortunately is still not commercially
available. Alternatively, the Rutter stent is currently the best available
solution and is used by us as standard. This stent can be individually
shortened, but it is not adapted to the laryngeal anatomy. Overall, however, the
issue of postoperative stenting, especially in children, is still not
satisfactorily resolved in many aspects.
Granulation and edema formations occur relatively regularly on the lumen-facing
graft surfaces. A control endoscopy with the option of granulation removal
should be performed regularly after about 3 weeks. Persistent granulations can
often be improved very well by topical application of mitomycin-C (dosage 2
mg/ml). Finally, when successful airway reconstruction is confirmed during a
control endoscopy, the stepwise decannulation procedure can be performed.
Usually, this is done by first gradually reducing the cannula size (downsizing)
followed by unplugging the cannula. The final step is taping of the tracheostoma
prior to surgical tracheostoma closure. In adulthood, this process can usually
be significantly shortened.
9. Special surgical procedures in pediatric patients
9. Special surgical procedures in pediatric patients
9.1 Extended CTR
In cases of pathological changes in several segments involving the glottis
(multilevel stenoses), a combination of CTR and LTR may be indicated. In this
case, the subglottic portion is resected to just below the level of the
subglottic slope of both vocal folds. The glottic stenosis is widened by
splitting the cricoid cartilage plate with insertion of a rib cartilage graft in
the sense of a posterior LTR ([Fig. 13]).
The thyrotracheal anastomosis allows extensive mucosal coverage of the cartilage
graft, which prevents granulation formation. Due to the extensive
destabilization of the laryngeal skeleton, postoperative stenting becomes
necessary and thus also the preservation or reinsertion of a tracheostoma below
the anastomosis, which is closed bilaterally after normalization of respiratory
function ([Video. 13]). shows multilevel
stenosis in a child, ([Fig. 13])
demonstrates the principle of reconstruction, [Video. 14] shows the healed situation after extended CTR.
Fig. 13 Principle of extended CTR. The procedure uses the
advantages of the combination of CTR and LTR for the treatment of
multi-level stenoses with glottic involvement. Source: Created by S.
Burger on behalf of the Klinikum Stuttgart
9.2 Laryngotracheal reconstruction with autologous thyroid cartilage
Today, this procedure can be considered the gold standard in the treatment of
connatal cricoid cartilage stenosis. However, the consistently positive
experience has also led to its use in other indications. In submucosal
extirpation of subglottic connatal cysts, LTR-S is a useful prophylactic measure
to avoid scarring stenosis. However, stenosis because of intubation-associated
scars can also be treated in infancy with surprisingly good results.
In this procedure, an approximately 2x3 mm piece of cartilage is harvested from
the free upper margin of the thyroid cartilage via an external approach ([Figs. 14]
[15]
[16]). This can be done
elegantly in the same surgical area without an additional incision. The graft is
inserted into the split cricoid cartilage and fixed with sutures.
Postoperatively, the child remains intubated for 2–4 days. This procedure is
successful in over 95% of cases and is associated with minimal additional
morbidity [25]. Of particular importance,
however, is that all reconstruction options remain undiminished, both classic
laryngotracheal reconstruction with autologous rib cartilage and cricotracheal
resection. Even if this approach does not succeed in reconstructing a
permanently adequate airway, the procedure can still be very valuable in
avoiding a tracheostoma in the first months of life and in bringing the child
with adequate translaryngeal breathing to an age when open reconstructions can
be used with very good prospects of success and an acceptable risk profile.
Fig. 14 Principle of autologous LTR with thyroid cartilage – first
step. Source: Created by S. Burger on behalf of the Klinikum
Stuttgart
Fig. 15 Principle of autologous LTR with thyroid cartilage –
second step. Source: Created by S. Burger on behalf of the Klinikum
Stuttgart
Fig. 16 Principle of autologous LTR with thyroid cartilage – last
step. This intervention is very helpful in infants with cricoid
cartilage stenosis and it is associated with low morbidity. Source:
Created by S. Burger on behalf of the Klinikum Stuttgart
The procedure is only slightly invasive and significantly less stressful than,
for example, a complete cricotracheal resection, a significant advantage in the
often multimorbid, syndromic, or for other reasons such as prematurity unstable
small patients.
LTR-S is therefore the procedure of choice for the treatment of subglottic airway
stenosis up to 18 months of age, almost regardless of the underlying etiology.
In an astonishingly large number of cases, it is even sufficient as a sole
measure to reconstruct a permanently adequate and co-extensive airway.
9.3 Reconstruction of a dorsal laryngeal cleft
Surgical closure of a dorsal laryngeal cleft is a surgical challenge. The risks
for the success of the procedure are not so much to be seen in the technical
execution, but much more in the biological peculiarities of the anatomical
region. The mucosal gap to be closed is located between the respiratory and the
alimentary tracts and is accordingly stressed with each swallow or breath. As a
result, healing is subject to great risk. In order to reduce the risk of
regurgitation of gastric juice, it is regularly recommended to perform a
fundoplicatio or to insert a feeding tube prior to closing the gap.
Another challenge is the age of the patients. In the vast majority of cases,
treatment takes place in the first year of life. The majority of patients have
additional malformations that increase the complexity of the therapeutic
strategy.
The surgical strategy depends on the extent of the finding. Type I and type II
laryngeal clefts are usually amenable to endoscopic exploration, whereas most
type III and all type IV clefts require external access and the creation of a
tracheostoma. Type IVb clefts with extension caudal to the upper thoracic
aperture or laryngo-tracheal clefts require intraoperative extracorporeal
membrane oxygenation (ECMO), otherwise exposure of the surgical site is not
possible.
9.4 Endoscopic closure of dorsal laryngeal clefts
Regardless of the access route, the principle of gap closure is the same: the
mucosa of the open gap between the larynx and esophagus/hypopharynx must be slit
and then closed in two layers, laryngeally and pharyngeally, using absorbable
single-knot sutures ([Fig. 17]).
Fig. 17 Principle of two-layer closure of a laryngeal cleft. The
separation of the laryngeal mucosa from the esophageal mucosal layer
prior to suture of the cleft edges is central for a successful
intervention.
Endoscopic procedures are technically demanding and require very close
cooperation between the surgeon and the anesthesia team. In most cases, the
patients are very young and do not have a tracheostoma. Therefore, surgery is
only possible with the use of supraglottic jet ventilation. Alternatively, a
temporary tracheostomy may be unavoidable.
Adjustment of the dorsal larynx is best accomplished using a Lindholm
laryngoscope. There is one manufacturer of jet ventilators on the market that
allows controlled ventilation of infants from 1,000 g body weight using a
technology specially developed for this age group.
Free and complete exposure of the gap is an essential prerequisite for optimal
mucosal suturing. This is best achieved in our hands by using a vocal fold
spreader ([Fig. 18]), which is locked
inside the Lindholm tube with the handle facing upwards.
Fig. 18 Exposition of a dorsal laryngeal cleft of type III using a
vocal fold spreader. This instrument is also used for checking the
passive mobility of the glottis.
The mucosal slitting is performed under microscopic control using a
CO2 laser, whereby care must be taken to minimize carbonization
of the cut edges. The free mucosal edges are to be handled atraumatically so as
not to additionally jeopardize the healing of the anastomosis. The absorbable
sutures are advanced and then immersed one by one, using a knot pusher. The
technique requires patience and consideration for the respiratory needs of the
child, which must be closely coordinated with the anesthesia team.
If possible, insertion of a naso-gastric feeding tube should be avoided, as it
poses additional risks to the sutures due to mechanical stress and as a guide
for gastric juice.
9.5 Open closure of dorsal laryngeal clefts
The vast majority of type III and all type IV laryngeal clefts require an open
approach. For this purpose, the trachea is opened up to the caudal fundus of the
fissure, as well as the cricothyroid cartilage, the cricothyroid membrane and
the thyroid, in each case strictly in the midline. This complete laryngofissure
must be performed exactly in the center in the area of the anterior commissure
under visualization with surgical loupes, then later synechia of the vocal folds
is generally not to be feared. After insertion of the laryngofissure retractor,
the overview of the dorsal fissure formation is excellent. After decongestion
with topical suprarenin, the lateral portions are separated into an anterior and
a posterior flap. Particular attention must be paid to complete
de-epithelialization of the cleft, especially in the fundus of the cleft, as
this is the predilection site for recurrence. Then the two posterior mucosal
flaps are adapted first, followed by the two anterior mucosal flaps with single
button sutures. If sufficient mucosa is available and especially in revisions, a
graft can be interposed, such as sternal or tibial periosteum, more rarely
fascia lata, temporalis fascia or perichiondrium from the ear cartilage.
Closure of the laryngofissure is level-adjusted and almost never leads to wound
healing problems. Postoperative stenting is not necessary, but the creation of a
tracheostoma is. A gastric tube should be avoided in order to prevent additional
foreign body pressure on the reconstruction. The child should already have been
treated with a PEG or PEJ beforehand. Closure of the tracheostoma is possible
only after normalization of breathing and swallowing. Children tube-fed
immediately after birth often need many months to relearn the physiological
swallowing process, even if the anatomical situation could be reconstructed ad
integrum. [Video. 15] shows the
endoscopic diagnosis of a type III dorsal laryngeal fissure prior to
reconstruction via laryngofissure, [Video.
16] the same case during control endoscopy after wound healing has
been completed. In both cases, instrumental palpation is important to accurately
determine the extent or to detect remaining fistulas or insufficiencies.
9.6 Two-stage closure of laryngotracheal type IV clefts
The primary focus of care for neonates with type IV laryngotracheal clefts, which
typically extend just anterior to the tracheal carina, is respiratory
stabilization, achieving a safe airway as soon as possible, and preventing
aspiration. These are often premature infants with correspondingly low birth
weight, low tolerance to invasive procedures, and frequent multimorbidity due to
malformation of other organ systems. Therapeutic decisions should be made in
severe cases only after multidisciplinary discussion including a palliative care
perspective.
A first step is the creation of a gastrostoma with a jejunal part both to drain
gastric secretions and prevent gastroesophageal reflux and to provide jejunal
nutrition. Surgical correction of the intrathoracic tracheal cleft portion can
be accomplished with adequate safety only with the use of ECMO or
cardiopulmonary machine, for which a body weight of approximately 2,000 g is
usually required. The creation of a tracheostoma only makes sense if the
tracheal cleft is closed at least up to the level of the stoma to allow a safe
change of cannulae. The creation of a tracheostoma is therefore combined with
the closure of the tracheal portion of the cleft. Via a right-lateral thoracic
approach, the two lateral portions of the fissure are adapted using a technique
analogous to the one described in the previous section. Usually, the present
tissue material proves to be redundant with, as a consequence, often a
persistent tracheomalacia symptomatology. Another problem is the possible
formation of steps at the transition of the reconstructed pars membranacea to
the intact one at the fundus of the former fissure. In case of an unfavorable
choice of the tracheal cannula length, the cannula tip may come to rest in this
area, which may lead to relevant obstructions and mucosal lesions. Endoscopic
control of the surgical success as well as of the cannula position is therefore
already indicated intraoperatively.
Surgical closure of the laryngeal and any residual tracheal cleft can then
usually be performed after 6–12 weeks, depending on the stability and thriving
of the child. The surgical procedure corresponds to the one described in the
previous chapter.
In our experience, tracheal cleft recurrences are rare and typically occur at the
junction of the laryngeal and thoracic cleft [24]. In contrast, tracheomalacia is almost obligatory and may require
long-term ventilation.
In the course of often several years, after stabilization of the tracheomalacia
and growth of the child, weaning from home ventilation and later decannulation
is possible.
A pronounced failure to thrive despite probing of high-caloric food via
jejunostoma is observed in many children with type IV cleft. In this case,
additional caloric food fortification is required. Swallowing and esophageal
function may remain compromised for a long time. Recurrent aspiration and
subsequent respiratory infections may accordingly persist despite good surgical
success. Nevertheless, recurrence of cleft should be excluded.
