|Year : 2016 | Volume
| Issue : 2 | Page : 56-62
Flexible bronchoscopic insertion of self-expanding metal stents in malignant tracheal lesions without fluoroscopic guidance
Karan Madan, Kavitha Venkatnarayan, Anant Mohan, Vijay Hadda, GC Khilnani, Randeep Guleria
Department of Pulmonary Medicine and Sleep Disorders, All Institute of Medical Sciences, New Delhi, India
|Date of Web Publication||10-Jun-2016|
Department of Pulmonary Medicine and Sleep Disorders, All India Institute of Medical Sciences, Ansari Nagar, New Delhi - 110 029
Source of Support: None, Conflict of Interest: None
Background: Self-expanding metal stents (SEMS) are a well-accepted treatment modality for malignant tracheobronchial obstruction or malignant tracheoesophageal fistulae (TEFs). The traditional approach to SEMS insertion in central airway obstruction (CAO) has been rigid bronchoscopy performed under general anesthesia. Fluoroscopic guidance is sometimes utilized. Safe and accurate placement of tracheobronchial SEMS has also been described using flexible bronchoscopy. We herein describe our experience with tracheal SEMS insertion using flexible bronchoscopy without fluoroscopic guidance. Methods: A retrospective analysis of the bronchoscopy records was undertaken for the duration June 2012 to June 2014. Patients with malignant CAO or malignant TEF who underwent tracheal SEMS insertion using flexible bronchoscopy were included. Procedures were performed under mild sedation. Fluoroscopic guidance was not utilized. Results: Eleven patients were identified. The mean age was 60.9 (12.8) years. There were 6 males and 5 female patients. Most common indication for tracheal SEMS was CAO (9/11) followed by TEF (2/11). Stent deployment could be accomplished successfully and at the desired location in all the patients. All patients reported immediate symptomatic relief. Two patients experienced peri-procedural respiratory failure that recovered within 24 h. There was no procedure related mortality or other major complications. Conclusion: Insertion of tracheal SEMS in patients with malignant CAO/TEF using flexible bronchoscopy under minimal sedation is a safe and efficacious modality that can be performed without fluoroscopic guidance.
Keywords: Bronchoscopy, central airway obstruction, esophageal cancer, lung cancer, self-expanding metal stents, stents
|How to cite this article:|
Madan K, Venkatnarayan K, Mohan A, Hadda V, Khilnani G C, Guleria R. Flexible bronchoscopic insertion of self-expanding metal stents in malignant tracheal lesions without fluoroscopic guidance. J Assoc Chest Physicians 2016;4:56-62
|How to cite this URL:|
Madan K, Venkatnarayan K, Mohan A, Hadda V, Khilnani G C, Guleria R. Flexible bronchoscopic insertion of self-expanding metal stents in malignant tracheal lesions without fluoroscopic guidance. J Assoc Chest Physicians [serial online] 2016 [cited 2021 Aug 3];4:56-62. Available from: https://www.jacpjournal.org/text.asp?2016/4/2/56/168619
| Introduction|| |
Central airway obstruction (CAO) particularly tracheal obstruction is a life-threatening emergency resulting from a number of pathological conditions of which malignant conditions are the commonest. Apart from airway obstruction, the clinical course of these patients is often complicated by tracheoesophageal fistulization that can have a significant negative impact on the quality of life (QOL). Prompt and judicious clinical decision making is often required, as the time window for the performance of a palliative/therapeutic procedure is minimal. Though the definitive management is surgery, it is often not feasible in patients with advanced malignancies with coexistent comorbid illnesses and poor general condition. Interventional bronchoscopic procedures are indispensible therapeutic modalities that are associated with improvements in QOL.
In emergent CAO, rigid bronchoscopy with relief of tumor obstruction (using mechanical coring with barrel of the rigid bronchoscope or using additional thermo-ablative modalities like laser/electrocautery/argon plasma coagulation) with/without subsequent airway stenting (silicon or self-expanding metal stents [SEMS]) is the usual procedure of choice., Insertion of SEMS has also been described with exclusive use of flexible bronchoscope in malignant tracheobronchial stenosis/tracheoesophageal fistula (TEF). We herein describe our preliminary experience with insertion of tracheal SEMS without fluoroscopic guidance performed under sedation in patients with either malignant CAO or tracheoesophageal fistulization.
| Methods|| |
A 2 years retrospective review of bronchoscopy records was undertaken for the duration June 2012 to June 2014. Patients were selected wherein tracheal self-expanding metallic stents had been inserted with the exclusive use of the flexible bronchoscope for malignant CAO or malignant TEFs. The procedures were performed at the Department of Pulmonary Medicine and Sleep Disorders in the All India Institute of Medical Sciences, New Delhi, India. Procedures were performed as part of the routine clinical protocol and written informed consent for the procedure was obtained from all the patients. All procedures were performed in the bronchoscopy suite under sedation.
All patients with suspected CAO were initially evaluated with a computed tomography (CT) scan examination of the thorax and neck (to ascertain the nature and extent of the underlying condition) followed by a diagnostic flexible bronchoscopic examination. The CT reconstruction images allowed assessment of the transverse and anteroposterior tracheal diameter of the uninvolved trachea above and below the diseased/obstructed segment and the length and diameter of the appropriate SEMS was decided accordingly. Length of the diseased segment was measured by slowly withdrawing the bronchoscope from distal to proximal end of the malignant stenosis/fistula wherever it was possible to obtain a distal visualization beyond the obstruction else the decision was undertaken based on the CT images. All the stents deployed were covered self-expanding metallic stents (Ottomed stent, Mitra Industries, India). A complete hemogram including the platelet counts, prothrombin time and activated partial thromboplastin time values were obtained prior to the procedure. Other relevant investigations as appropriate were performed in all patients.
The patient was kept nil per orally preferably for at least 4 h (ideally for 6–8 h if the clinical condition permitted) prior to the therapeutic bronchoscopy procedure. The decision to administer/dose of sedation was based on the clinical judgment of the operator. All procedures in our study were performed under sedation. Peripheral intravenous access was secured. Topical spray of 10% lignocaine was applied to the posterior pharyngeal wall. Intravenous sedation included either a short acting benzodiazepine (midazolam) or opioid (fentanyl) either singly or in combination. Supplemental oxygen was given through nasal cannula.
Flexible bronchoscopy was performed using either the Olympus BF-1T-180 video-bronchoscope or the Olympus BF-TE2 fiber optic bronchoscope (Olympus Medical Corporation, Japan). With the patient in supine or semi-recumbent (or sitting position if patient was unable to lie supine), flexible bronchoscope was introduced through the oral route after insertion of a bite block and was advanced across the vocal cord into the trachea till above the diseased segment. Topical lignocaine was administered as “Spray as you go” method. A guide-wire was inserted through the working channel to pass distal to the obstruction, and the bronchoscope was withdrawn leaving the guide-wire in place. The stent loaded within the stent deployer was gently threaded over the guide-wire via the oral route. Visualization during the insertion of the stent deployer was obtained by the flexible bronchoscope inserted via the nasal route. It was positioned and guided just proximal to the distal tip of the stent deployer. The deployer was advanced beyond the stenosis and stent deployment was performed. The deployer along with the guide-wire was removed and the bronchoscope was introduced into the lumen of the stent to ascertain correct deployment [Figure 1] and [Figure 2]. Fluoroscopic guidance was not employed. Repositioning if required was done by grasping the threads at either end of the stent using a flexible grasping forceps. Following correct positioning of the stent and suctioning to clear the bronchial secretions, the flexible bronchoscope was removed.
|Figure 1: Steps involved in flexible bronchoscopic insertion of tracheal self-expanding metal stents. Panel (a) - Guide-wire inserted into the trachea and positioned in one of the distal bronchial segments; Panel (b) - Stent deployer being negotiated across the vocal cord under bronchoscopic visualization; Panel (c) - Stent deployer negotiated into the trachea; Panel (d) - Stent being deployed/opened at the distal end of the endoluminal lesion; Panel (e) - Completely opened distal end of the self-expanding metal stent after successful insertion; Panel (f) - Bronchoscopic image showing the proximal end of inserted self-expanding metal stent|
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|Figure 2: Panel (a) - Bronchoscopic image showing 80% tracheal luminal narrowing due to extrinsic compression and submucosal infiltrative lesion in a patient with small cell lung cancer; Panel (b) - Restoration of tracheal lumen after successful self-expanding metal stent insertion, carina is normally visualized; Panel (c) - Bronchoscopic image of endotracheal exophytic growth causing 90% narrowing of tracheal lumen in a patient with adenoid cystic carcinoma; Panel (d) - Tracheal self-expanding metal stent seen completely covering the endotracheal lesion with restoration of tracheal luminal patency|
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Hemodynamic monitoring included monitoring of heart rate, blood pressure, ECG, and pulse oximetric saturation throughout the procedure and the immediate postprocedure duration. All the patients were observed for a minimum of 24 h duration in the hospital. A chest radiograph (over penetrated film) was performed 3–4 h later to ascertain correct positioning [Figure 3]. A check bronchoscopic examination was performed prior to discharge. Follow-up bronchoscopy was scheduled 4 weeks later. Patients were advised to take saline nebulization or steam inhalation at home to ease in expulsion of secretions.
|Figure 3: Panel (a) - Computed tomography thorax showing eccentric endotracheal growth causing central airway obstruction in a patient with squamous cell carcinoma; Panel (b) - Chest radiograph showing tracheal self-expanding metal stent after deployment in the same patient (arrow)|
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A descriptive analysis was performed. Categorical variables were expressed as frequency (percentages) and quantitative variables were expressed as mean (standard deviation) or median (interquartile range).
| Results|| |
During the study period, 11 patients underwent tracheal SEMS placement under flexible bronchoscopy. There were 6 males (55%) and 5 females (45%). The mean age was 60.9 (12.8) years ranging from 32 to 75 years. Indications for the procedure included malignant tracheal obstruction in 9 patients (82%) and TEF in 2 (18%) patients. These details are summarized in [Table 1].
|Table 1: Baseline characteristics, indications, procedure details, and follow-up of patients undergoing tracheal SEMS insertion|
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Common symptoms at the time of presentation included dyspnea and stridor (72%), dysphagia (36%) and paroxysmal coughing on swallowing (18%). One patient had clinical and radiological evidence of superior vena cava obstruction. Both the patients with TEF were diagnosed with advanced stage esophageal squamous cell carcinoma. The etiological diagnoses in the remaining patients included esophageal carcinoma with tracheal involvement (4 patients – 36%), small cell lung cancer (2 patients – 18%), nonsmall cell lung cancer (4 patients [1 adenocarcinoma, 3 squamous cell carcinoma] – 36%] and adenoid cystic carcinoma of the trachea in 1 patient – 9%. In 9 of the 11 patients (91%), a histological diagnosis was already available at the time of presentation. In the remaining two patients, tracheal stenting was performed for immediate airway stabilization. Definitive diagnosis of malignancy was subsequently established by transbronchial needle aspiration (1 patient) [Figure 4] and cervical lymph node biopsy (1 patient).
|Figure 4: Bronchoscopic image showing transbronchial needle aspiration being performed from the subcarinal station after successful tracheal self-expanding metal stent insertion in a patient with small cell lung cancer|
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The mean duration of the procedure was 32.5 (5.26) minutes. The mean dose of midazolam used was 3.09 (0.5) mg and fentanyl was 61.3 (13.0) mcg. Endobronchial electrocautery debulking (using hot biopsy forceps and coagulation electrode) was utilized as an adjunct prior to tracheal stenting in 1 patient. Cryotherapy was additionally employed in one patient. In all the remaining patients, tracheal SEMS insertion was the only procedure performed. Of the 11 patients, 8 patients (72%) presented with emergent CAO wherein the procedure had to be performed immediately.
Overall, SEMS placement could be accomplished successfully in all the patients. Minor complications included mild postprocedural hemoptysis (3 patients – 27%) which improved spontaneously. Others included sensation of poststenting chest discomfort and cough that improved. None of the patients had stent migration or pneumothorax/pneumomediastinum following the procedure.
Uncomplicated successful deployment of the tracheal SEMS could be accomplished during the initial attempt in 10 of the 11 patients. Procedural complications occurred in 2 patients (18%). Both these patients had presented with critical airway narrowing of the trachea and were hypoxemic at presentation. In one patient (nonsmall cell lung cancer), though the tracheal SEMS could be deployed successfully and tracheal patency was achieved during the initial attempt, the patient had worsening respiratory acidosis immediately poststenting and required mechanical ventilation for 24 h. The patient was successfully extubated the following day. However, the patient expired a week later due to hospital acquired pneumonia and sepsis. In the second patient with esophageal carcinoma, worsening hypercapnia during the bronchoscopic examination necessitated bronchoscopic intubation and assisted mechanical ventilation. SEMS insertion was performed 24 h later following which the patient could be immediately liberated from the ventilator and discharged home after 2 days.
Symptomatic relief was reported by all patients immediately after the procedure. There was no procedure related mortality or other major complications. One patient expired 1-week following stenting due to nosocomial infection. All the remaining patients had subjective improvements in QOL. At 4 weeks of follow-up bronchoscopic examination in the remaining patients, none had stent migration or granulation tissue formation requiring bronchoscopic intervention.
| Discussion|| |
CAO refers to luminal compromise of the trachea or the major bronchi. Most common etiologies are malignancies including lung cancer, lymphomas, esophageal cancer, thyroid cancer, and metastases. Malignant CAO may be due to endoluminal growth or extrinsic compression of the airways or a combination of both. Malignant CAO often presents as a life-threatening airway emergency requiring emergent intervention. Patients often seek medical attention late as dyspnea occurs when the tracheal lumen is reduced to <8 mm and respiratory distress at rest when the lumen is <5 mm. Interventional bronchoscopy is the treatment modality of choice in surgically inoperable patients with emergent CAO and improves the QOL in addition to the relief of dyspnea. Options include mechanical coring with the barrel of the rigid bronchoscope, laser ablation, electrocautery, and stenting., In nonemergency situations, options like intraluminal brachytherapy, cryotherapy, and photodynamic therapy may be considered., Surgery is frequently not possible in many patients with malignant CAO as performance status is poor and respiratory failure necessitates an emergent bronchoscopic life-saving measure to restore airway patency.
Malignant TEFs are a complication of esophageal or lung cancer and lead to persistent communication between the esophagus and trachea causing recurrent aspiration. They are associated with high mortality with mean survival of 1–6 weeks. Most of the patients are inoperable at the time of presentation with severely compromised QOL. Palliative stenting of the esophagus or the trachea leads to sealing of the defect and improvement in symptoms and improvement in QOL., Combined stenting of the airway and the esophagus has been shown to improve survival compared to single stent placement.
Airway stenting is usually done with the following intent: Establishing airway patency, sealing fistulas or to stabilize weakened airway walls.
SEMS are made of nitinol, an alloy containing nickel and titanium, with properties similar to the tracheal cartilage. It is highly elastic, biocompatible, kink resistant, offers less resistance to cough and has “shape memory” facilitating retention of its original shape following compression., It has been shown to have a low complication rate and can be used even in complex airway stenoses. The stents also have threads at the end that can be held with forceps for manipulation and proper positioning. It is easier to pull a distally deployed stent with the help of these threads than reposition a proximally deployed stent. SEMS have the advantages of easy deployment, stability in position, preserved mucociliary clearance (in uncovered SEMS) and adaptation to tortuous irregular airways. However, retrieval is difficult, and formation of granulation tissue and tumor ingrowth can occur over the course of time. If stent retrieval is deemed necessary at any point, bronchoscopic removal can be attempted which usually involves the use of a rigid bronchoscope and extraction using the rigid forceps. In some patients, surgical intervention and rarely thoracotomy may be required for the same.
Traditionally airway stenting was performed using a rigid bronchoscope under general anesthesia. However, expertise in rigid bronchoscopy is available only at a few centers. The availability and training in flexible bronchoscopy are however available more widely. With the introduction of SEMS, successful flexible bronchoscopic airway stenting under conscious sedation has been described., The initial cases of tracheobronchial SEMS insertion using flexible bronchoscopy were reported in 1994. In a single center retrospective analysis, McGrath et al. showed that SEMS were safe and effective in the management of inoperable tracheobronchial stenoses. It offered immediate symptomatic relief and prolonged survival. It was also highlighted that it can be easily performed in a respiratory unit under sedation without general anesthesia.
Conventionally fluoroscopy was used to confirm the position of the stent. But this requires specialized equipment and additional staff. It also carries the risk of radiation exposure to the patients and the medical personnel. Few studies have reported the safety of insertion of SEMS under direct vision without fluoroscopy. This has further simplified the procedure of airway stenting and minimizes radiation exposure. It has also been shown to be safe in mechanically ventilated patients and help in liberation from ventilator. In patients wherein bronchoscopic visualization distal to the obstruction is possible, fluoroscopy is not required and stent deployment can be performed under direct visualization. We believe that fluoroscopy may be useful in patients wherein bronchoscopic visualization distal to the obstruction is not possible and therefore the use of fluoroscopy can enable correct positioning of the guide-wire over which the SEMS can be threaded and eventually deployed.
It should however be noted that airway stenting using the flexible bronchoscope in patients with CAO is a challenging procedure and requires training and expertise. Incorrect patient selection and failure to have a back-up plan (like rigid bronchoscopy standby) may be associated with deleterious outcomes. Therefore operator experience and adequate training of the bronchoscopy staff is of paramount importance. The procedure of tracheal stenting in patients with uncomplicated malignant TEF without significant airway compromise is less complicated.
Our study highlights that airway stenting using flexible bronchoscopy is a safe and effective option for patients with inoperable malignant airway obstruction. It offers the advantage of abating the need for general anesthesia. It can also be done safely in the absence of fluoroscopic guidance thus avoiding radiation exposure, and the position of the stent can be confirmed by direct vision. SEMS offer the advantage of easier deployment with minimal complications.
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