Keywords
central airway obstruction - endobronchial stenting - tracheoesophageal fistula -
SEMS
Background
Central airway obstruction can be of benign or malignant etiology, of which malignancy
is the more common cause. Malignant central airway obstruction occurs in ∼20 to 30%
of patients with lung cancer and is usually associated with poor prognosis. Timely
therapeutic intervention, endobronchial debulking and tracheobrochial stenting give
immediate relief to the patient by improving the airway lumen and hence a better quality
of life.
Tracheoesophageal fistula (TEF) is a pathological communication of the trachea and
the esophagus. It can be congenital or acquired. It can be further classified as benign
etiology or malignant etiology. Thoracic malignancy such as carcinoma lung or esophagus
can lead to TEF by direct extension of the tumor, as a result of surgery, chemotherapy,
radiotherapy or pre-existing stent erosion into the adjacent structures. Due to the
advanced stage of malignancy, most patients will be eligible only for palliative procedures
such as endobronchial stenting as compared with surgery. Hereby, we present three
such scenarios of tracheobronchial stenting for palliative purpose.
Case Presentation
Case 1
A woman in her late 40s presented with a diagnosis of carcinoma middle one-third of
the esophagus with systemic hypertension presented with a history of cough, expectoration,
and exertional dyspnea since 4 weeks. Expectoration was mucoid in consistency, nonfoul
smelling, and not blood-stained. There were no complaints of fever, chest pain, orthopnea,
or paroxysmal dyspnea. She also had complaints of dysphagia, generalized weakness,
and loss of weight. Her dysphagia was more to solids than liquids. She was diagnosed
with squamous cell carcinoma esophagus 1 year ago for which she had received radiotherapy
and chemotherapy. On examination, she had a saturation of 90% in room air, a heart
rate of 100 bpm, a respiratory rate of 25 breaths per min, biphasic stridor, and respiratory
distress. She had made multiple hospital visits for recurrent respiratory infections
and was under follow-up with her oncologist for regular chemotherapy and radiation
therapy. She underwent a diagnostic bronchoscopy in her local hospital that revealed
the central airway obstruction secondary to the extension of the esophageal growth
into the trachea. She was referred to our center for further management of the endotracheal
obstruction.
All relevant investigations were done. A blood workup showed leukocytosis. Liver and
renal function tests were within normal limits. CECT showed soft tissue density-enhancing
mass lesion measuring 20 × 23 × 27 mm in the upper thoracic esophagus at D1 and D2
levels. Anteriorly, it is seen infiltrating the tracheal lumen causing luminal stenosis
The patient was started on oxygen via nasal cannula at 2 L/min, antibiotics, steroids
and bronchodilator nebulization. Oxygen tapered to room air gradually. Repeat CT thorax
and 3D reconstruction of the central airways were done to find out the extent of the
lesion. The lesion was located at a distance of 52.9 mm from the subglottis and the
extent of the lesion was 17.2 mm. The lesion caused a near-total occlusion of the
trachea leaving behind a narrow opening of 2.4 mm for ventilation ([Figs. 1]–[2]) A flexible self-expanding metallic stent of 6 cm in length was chosen to have a
margin of 2 cm on either side of the lesion. The patient was intubated with the rigid
tracheoscope under general anesthesia in the operating room. Under direct vision with
the telescope, the guidewire was passed through the narrow lumen beyond the lesion
and a self-expanding stent was deployed. ([Fig. 3]) The patient was extubated on the table, she tolerated the procedure well. Post-procedure
repeat CT thorax was done to assess the stent expansion and placement. Tracheal lumen
patency was re-established. The patient's respiratory distress reduced and was discharged
the next day on steroids, antibiotics, and antihypertensives. She was advised to follow
up on her chemotherapy and radiotherapy course.
Fig. 1 Pre procedure airway measurements – Distance of the stenosis from subglottis - 52.9 mm.
Length of stenosis – 17.2 mm. The patent lumen at the stenosed part – 2.4 mm.
Fig. 2 Bronchoscopic view of the intraluminal growth in the trachea causing near-total obstruction.
Fig. 3 Post procedure – post endotracheal stenting CT thorax view of the stenosed part.
The patient presented after 5 months of tracheal stent placement with complaints of
cough and expectoration since 4 weeks. On examination, saturation was 95% in room
air with bilateral equal air entry, and normal vesicular breath sounds. Repeat chest
X-ray and repeat bronchoscopy were done, which confirmed the position of the stent.
She was treated symptomatically and is undergoing regular chemotherapy.
Case 2
The second case is about a female patient in her late 50s who presented with a history
of cough, expectoration since 4 months. She had gradually progressive breathlessness
since 2 months. She also had an evening rise in temperature and loss of weight. However,
there was no dysphagia, hoarseness of voice, or abdominal complaints. On examination,
oxygen saturation was 98% in room air, pulse rate was 90 bpm, blood pressure was 120/80
mmHg, respiratory rate was 20 breaths per min. Respiratory system examination revealed
bilateral equal air entry, no added sounds. Patient had undergone flexible bronchoscopy
in another hospital which diagnosed an intraluminal growth in the lower end of the
trachea causing luminal narrowing histopathologically diagnosed as nonsmall cell lung
cancer – squamous cell carcinoma. CT thorax and image 3D reconstruction of the central
airways was performed to confirm the obstruction, examine for distal airway patency,
and find the extent of the lesion. The intraluminal lesion was located in the lower
end of the trachea arising from the right later wall of the trachea. The lesion extended
for 22.4 mm with the narrowest part of the lumen measuring 1.3 mm. Under general anesthesia,
rigid bronchoscopic intubation was done, a flexible bronchoscope was used to pass
the guidewire beyond the lesion. Self-expanding metallic stent deployed under fluoroscopic
guidance ([Fig. 7]). It is worth noting the difficulty while deploying the stent that the stent was
getting deployed much proximally as expected. The stent had to be withdrawn out through
the rigid bronchoscope to be reloaded and redeployed much distally to the expected
stent placement location. The stent position was confirmed by a flexible bronchoscope
and chest X-ray. Tracheal lumen re-established thereby immediately relieving the patient's
symptoms ([Fig. 4]). The patient was referred to a medical oncologist for further management.
Fig. 4 Re-established lumen after endotracheal stenting.
Case 3
The third case was a male patient in his sixth decade presented with a cough since
1 month, vomiting since 1 month, fever episodes on, and off since 1 week. The patient
also had a history of weight loss and loss of appetite. On examination, he had an
oxygen saturation at 96% in room air, pulse rate was 95 beats per min, and respiratory
rate was 18 breaths per min. Respiratory system examination revealed equal air entry
bilaterally and crepitations in infra scapular and mammary areas. Upper gastrointestinal
scopy was done with a biopsy from the middle-third of the esophagus, which turned
out to be squamous cell carcinoma. The patient was referred to look for a trachea
esophageal fistula. Flexible bronchoscopy was done, which showed a fistulous opening
connecting the trachea and esophagus at the lower end of the trachea just above the
carina ([Figs. 5] and [6]). Rigid bronchoscopy was done under general anesthesia. The challenge during the
stent placement was that after deployment of the stent, the polyvinyl bead at the
distal end of the stent deployer dislodged and remained behind in the airway. The
polyvinyl bead of the stent deployer had to be removed. Because the conical part was
difficult to grasp with rigid forceps, fogarty balloon was passed distal to it and
slowly withdrawn. The stent was reloaded and deployed under fluoroscopic guidance.
The rent in the airway was covered by the stent. The patient's presenting symptoms
reduced.
Fig. 5 Tracheo esophageal fistula in the lower end of the trachea.
Fig. 6 Conical distal end piece of the stent deployer.
Discussion
Malignant central airway obstruction refers to a neoplastic narrowing of the trachea,
right and left main bronchus. Obstructive lesions are classified into intraluminal
(intrinsic), extraluminal (extrinsic), or a combination of both. The neoplastic etiology
can be a primary lung tumor or adjacent tumors such as esophageal, laryngeal, mediastinal
tumors, or lymphoma. Symptoms are dyspnea, cough, hemoptysis, wheezing, or post obstruction
pneumonia. Our patient had cough, wheezing, exertional dyspnea along with swallowing
difficulty.
Diagnosis is by flexible bronchoscopic examination and visualization of the trachea
bronchial obstruction. Once diagnosed, treatment is challenging due to the following
reasons a) difficult to debulk the tumor with a flexible bronchoscope owing to bleeding
and the need for rigid bronchoscopy and b) the risk of airway compromise and need
for a pre-decided plan of hemostasis such as electrocautery and APC.[1] The aim of treatment in malignant central airway obstruction is to re-establish
the patency of the airway lumen. In case of an intrinsic obstruction, this can be
achieved by tumor debulking by cryoprobe, multiple biopsies, and coring the tumor
with the beveled edge of the tracheobronchoscope. To maintain patency and prevent
the lumen to be compromised, a tracheobronchial stent may be placed. In case of an
extrinsic compression causing airway luminal narrowing, the patient benefits by the
placement of an airway stent along with treating the cause.[2] In our case, the patient underwent a check bronchoscopy with flexible bronchoscope,
followed by rigid bronchoscopy and tracheal stenting with a self-expanding metallic
stent.
A rigid tracheo-bronchoscope is the instrument of choice in case of airway manipulation
due to its larger lumen and ability to use varied instruments along with ventilation.[2] Because the lesion of interest in our case was in the mid-part of the trachea, a
rigid tracheoscope was used.
Airway stents have an important role in rapid and effective symptom-relieving in central
airway obstruction. Stents can be silicone, metallic, or hybrid material. Further
metallic stents are classified into uncovered, covered, and partially covered stents.
The choice of stent depends on the patient's pathology.[3] Metallic stents are difficult to remove as compared with silicone stents due to
the ingrowth of granuloma and tumor tissue around the stent. The general consensus
is that metallic stents are used in malignant obstruction as the stent will be left
in place for the rest of the patient's lifetime, whereas silicone stents can be removed
easily in the benign condition once the cause is treated. The US FDA recommends against
using metallic stents in benign conditions.[4] The commonest type of stent being used around the world is the covered self-expandable
metal stents (SEMS). Covered SEMS mean use was 44%, followed by the silicone stents
(37%), Y stents (15%), uncovered SEMS (12%), and Montgomery T tube (5%).[5]
TEF often occurs with tracheal and esophageal malignancies. Approximately 5 to 15%
of patients develop TEF due to esophageal malignancy, while 1% are caused by bronchogenic
carcinoma.[6] Patients usually present with cough while having food or fluids, purulent bronchitis,
and pneumonia. In view of advanced disease in malignancy patients, surgery is often
not possible. Such patients are ideal for tracheal stenting with or without esophageal
stenting.
