Discussion
In the pediatric population, intubation-related tracheal tear due to a
large endotracheal size is the most common mechanism of airway injury,
so selection of appropriate tube size is essential (3,4). Furthermore,
frequent manipulation of the tube without overinflation or deflation and
intubation performed by inexperienced clinicians are common causes of
tracheal tears (5).
Tracheostomy-related posterior tracheal tears occur infrequently and are
less commonly than intubation-related tracheal tear. They usually occur
during tracheostomy placement, use of cuffed tubes, and overinflation of
the cuff or tear following tracheal trauma during introducer insertion
(6,7,8). Tracheostomy-related tears are is mainly located proximal to
the carina and distal to the insertion point of the tracheostomy.(3,9)
Pediatric patients are at higher risk of iatrogenic tracheal tears than
adults due to anatomical differences: weaker intercartilaginous
membrane, higher cartilage elasticity, and smaller airway lumen. In
addition, the mortality rate in pediatric patients after iatrogenic
tracheal tears is as high as 75%, so the selection of the appropriate
tube size is essential (3). Short thick neck, kyphoscoliosis, and
emergency cases with difficult intubation increase the risk of tracheal
tears in pediatric patients (1,7,9).
Iatrogenic trachel lacerations may present immediately as impaired
ventilation or later in the postoperative period with the complications
of compressive pneumothorax, pneumomediastinum, or extensive
subcutaneous emphysema, especially during retching or coughing or in
mechanically ventilated patients (1,10). Furthermore, tracheobronchial
tears can lead to many other complications such as respiratory distress,
mediastinitis, tracheal stenosis, recurrent nerve injury, fistula, and
abscess. The gold standard for diagnosis is flexible or rigid
tracheobronchoscopy, which helps determine the site, extension, and
location of the tear with respect to the carina. Imaging studies such as
computed tomography (CT) can help identify complications such as
pneumothorax, pneumonia, pneumomediastinum, and mediastinitis. Chest and
lateral neck radiographs are helpful too, but they have a false negative
rate reaching 10% (1,2,5,9,10). In addition, esophagoscopy is essential
to rule out esophageal injuries (3,10). In 88% of cases, tears are
diagnosed intraoperatively because of emphysema in the mediastinum or
impaired ventilation (11).
Treatment can be conservative or surgical. Conservative treatment is
indicated for mechanically ventilated patients and hemodynamically
stable patients with uncomplicated and small (<3 cm) tears, no
protrusion of mediastinal structures into the tracheal lumen, and only
mild emphysema. Conservative treatment includes the insertion of
longer/adjustable-length tracheostomy tubes or endotracheal tube,
preferably under endoscopic guidance with an appropriate tube size,
which is placed distal to the tear site with continuous cuff pressure
measurement. If the tear is close to the carina, positioning the cuff
distal to the tracheal tear is challenging, so tube placement should be
performed under endoscopic guidance to ensure proper tube placement,
along with continuous cuff pressure measurement to avoid tear
enlargement (1,5,10,12-14). Furthermore, the approach to mechanical
ventilation is important as positive pressure ventilation can exacerbate
the injury. On the other hand, ventilation helps the tear to
spontaneously collapse, thus supporting tear healing. All this should be
done under the cover of a broad-spectrum antibiotic to reduce the risk
of infection (1,3,10). Surgical treatment is preferred for patients with
large or complicated tears, tracheal avulsion, and extensive emphysema
and those who are unstable during ventilation. Surgical repair should be
performed as soon as possible to decrease the risk of complications. The
choice of surgical approach should be guided by the anatomical site of
the tear. Using the tracheostomy opening is highly recommended because
the incision already exists and the laceration is almost always proximal
to the carina and rarely extends beyond it (1). Deganello et al.
described surgical repair of a large proximal tracheal tear that ended
above the carina in an adult patient through an extended tracheotomy
opening technique with interrupted sutures using a thoracoscopic needle
holder (1). Welter et al. described a repair of similar tear with no
surgical access using an optical needle holder with interrupted sutures
through rigid bronchoscopy (13). Chaaban et al. treated a large tear in
a surgically unfit tracheostomized adult patient using a customized
silicone stent, which was inserted under bronchoscopy guidance to bridge
the tear end. Then, at the level of the tracheostomy site, an anterior
window was made in the stent to insert the tracheostomy tube through the
stent (14). If the tear extends up to the bronchial tree, thoracotomy is
required. Tears involving the carina, right bronchial tree, and proximal
region of the left main bronchus necessitate right thoracotomy. Left
thoracotomy is required if the injuries lie in the left main bronchus
near the lung hilum and left bronchial tree (5). If significant tracheal
mucosa injury and concern of stenosis are present, tracheal segment
resection with end-to-end anastomosis may be performed. In addition,
sealing the tear at the anterior esophageal wall can help secure the
tear. After the repair of the tear, a soft noncuffed tube should be
used. If a cuffed tube is used, the cuff pressure need to be monitored.
To decrease peristaltic movement, nasogastric tube should be inserted
for at least 1 week. For both surgical and nonsurgical treatment,
multiple follow-up chest and lateral neck radiography is needed, as well
as regular serial endoscopic examinations, such as daily bedside
fiberoptic endoscopy and bronchoscopy for a few days. During assessment,
the endotracheal or tracheostomy tube should be carefully retracted to
check for healing, proper tube placement at a suitable level, and
evidence of stenosis or tracheoesophageal fistula (1,9,11).