Timing of silicone stent removal in patients with post-tuberculosis bronchial stenosis

Management of post-traumatic tracheal stenosis with silicone stent placement

Benign airway stenosis often poses a therapeutic challenge and requires a multidisciplinary approach involving interventional pulmonologists and thoracic surgeons. We report the case of a man who presented with thoracic trauma following a road traffic accident. His chest X-ray showed complete collapse of the right lung, while screening flexible bronchoscopy revealed pooled secretions and asymmetric mid-to-lower tracheal stenosis. After thorough clinicoradiological evaluation and multidisciplinary discussion, we proceeded with therapeutic rigid bronchoscopy and silicone stenting of the tracheal stenotic lesion. Post-procedure, the patient improved clinically and also showed radiological improvement. Subsequently, he underwent stent removal and remains in follow-up. While surgery is a definitive modality for management of benign tracheal stenosis, most patients with advanced disease, pneumonia or with poor general condition are unfit to tolerate general anaesthesia or surgery. In such patients, minimally invasive bronchoscopic techniques that are generally safe to perform have led to substantial improvement in symptoms and long-term quality of life.

Temporary Stenting for Anastomotic Stenosis after Tracheal Resection of Adenoid Cystic Carcinoma: A Case Report

A 51-year-old man who noticed discomfort in the pharynx was found to have a tracheal tumor on physical examination. He was diagnosed as having adenoid cystic carcinoma by a transbronchial biopsy and underwent tracheal segmental resection via a collar incision. He was additionally treated with radiation therapy owing to a positive surgical margin, and he subsequently developed anastomotic tracheal stenosis. Silicon stent placement to open the airway was performed for the tracheal stenosis. One year after stent placement, the trachea was dilated, so the stent was removed, and he is still under follow-up without recurrence free 1.5 years after stent replacement.

Clinical Factors for Successful Removal of Airway Silicone Stents in Patients With Post-Tuberculosis Tracheobronchial Stenosis

BACKGROUND

After relieving stenosis with an airway silicone stent in post-tuberculosis bronchial stenosis (PTTS), stent removal is attempted if it is determined that airway patency can be maintained even after stent removal. However, the factors affecting airway stent removal are not well known. We investigate the factors that enable the successful removal of airway silicone stents in patients with PTTS.

METHODS

We retrospectively analyzed PTTS patients who underwent bronchoscopic intervention from January 2004 to December 2019. Successful stent removal is defined as airway patency maintained when the stent is removed, so that reinsertion of the stent is not required. A multivariate logistic regression analysis was used to identify independent factors associated with successful stent removal at the first attempt.

RESULTS

Total 344 patients were analyzed. Patients were followed up for a median of 47.9 (26.9-85.2) months after airway stent insertion. Approximately 69% of PTTS patients finally maintained airway patency after the stent was removed. Factors related to successful stent removal at the first attempt were older age and male sex. Absence of parenchymal calcification, segmental consolidation & bronchiolitis, and no trachea involved lesion were relevant to the successful stent removal. Stent dwelling for 12-24 months was associated with successful stent removal compared to a duration of less than 12 months.

CONCLUSION

For patients whose airway patency is determined to be maintained even without a stent, it is necessary to attempt stent removal in consideration of factors related to successful stent removal.

Rigid Bronchoscopy for Post-tuberculosis Tracheobronchial Stenosis

The healing process of tracheobronchial tuberculosis (TB) results in tracheobronchial fibrosis causing airway stenosis in 11% to 42% of patients. In Korea, where pulmonary TB is still prevalent, post-TB tracheobronchial stenosis (PTTS) is one of the main causes of benign airway stenosis causing progressive dyspnea, hypoxemia, and often life-threatening respiratory insufficiency. The development of rigid bronchoscopy replaced surgical management 30 years ago, and nowadays PTTS is mainly managed by bronchoscopic intervention in Korea. Similar to pulmonary TB, tracheobronchial TB is treated with combination of anti-TB medications. The indication of rigid bronchoscopy is more than American Thoracic Society (ATS) grade 3 dyspnea in PTTS patients. First, the narrowed airway is dilated by multiple techniques including ballooning, laser resection, and bougienation under general anesthesia. Then, most of the patients need silicone stenting to maintain the patency of dilated airway; 1.5 to 2 years after indwelling, the stent could be removed, this has shown a 70% success rate. Acute complications without mortality develop in less than 10% of patients. Subgroup analysis showed successful removal of the stent was significantly associated with male sex, young age, good baseline lung function and absence of complete one lobe collapse. In conclusion, rigid bronchoscopy could be applied to PTTS patients with acceptable efficacy and tolerable safety.

Trends and an Online Survey on the Use of Rigid Bronchoscopy in Korea

BACKGROUND

Although almost all interventional pulmonologists agree that rigid bronchoscopy is irreplaceable in the field of interventional pulmonology, less is known about the types of diseases that the procedure is used for and what difficulties the operators face during the procedure. The purpose of this study is to evaluate what diseases rigid bronchoscopy is used for, whether it is widely used, and what challenges the operators face in Korea.

METHODS

We enrolled 14 hospitals in this retrospective cohort of patients who underwent rigid bronchoscopy between 2003 and 2020. An online survey was conducted with 14 operators to investigate the difficulties associated with the procedure.

RESULTS

While the number of new patients at Samsung Medical Center (SMC) increased from 189 in 2003-2005 to 468 in 2018-2020, that of other institutions increased from 0 to 238. The proportion of SMC patients in the total started at 100% and steadily decreased to 59.2%. The proportion of malignancy as the indication for the procedure steadily increased from 29.1% to 43.0%, whereas post-tuberculous stenosis (25.4% to 12.9%) and post-intubation stenosis (19.0% to 10.9%) steadily decreased (all P for trends < 0.001). In the online survey, half of the respondents stated that over the past year they performed less than one procedure per month. The fewer the procedures performed within the last year, the more likely collaboration with other departments was viewed as a recent obstacle (Spearman correlation coefficient, r_s = -0.740, P = 0.003) and recent administrative difficulties were encountered (r_s = -0.616, P = 0.019).

CONCLUSION

This study demonstrated that the number of patients undergoing rigid bronchoscopy has been increasing, especially among cancer patients. For this procedure to be used more widely, it will be important for beginners to systematically learn about the procedure itself as well as to achieve multidisciplinary consultation.

Prognostic Factors for Tracheal Restenosis after Stent Removal in Patients with Post-Intubation and Post-Tracheostomy Tracheal Stenosis

PURPOSE

Long-term tracheal stent placement can increase the risk of stent-related complications; hence, removal of the stent after stabilization is attempted. However, little evidence has been established regarding the risk factors for tracheal restenosis. We aimed to identify the risk factors for tracheal restenosis in patients with post-intubation tracheal stenosis (PITS) and post-tracheostomy tracheal stenosis (PTTS).

MATERIALS AND METHODS

We retrospectively analyzed patients with PITS and PTTS between January 2004 and December 2019. Patients were classified into a success or failure group according to treatment outcomes. Patients with successful stent removal were defined as patients who did not require additional intervention after stent removal during the follow-up period. Multiple logistic regression analysis was performed to identify the factors associated with tracheal restenosis.

RESULTS

Among 269 stented patients, 130 patients who had removed the stent were enrolled in this study. During the follow-up period, 73 (56.2%) patients had a stable clinical course; however, 57 (43.8%) patients had restenosis. The proportion of trauma-induced intubation was higher in the success group than in the failure group (p=0.026), and the median stent length was shorter in the success group (45 mm) than in the failure group (50 mm, p=0.001). On multivariate analysis, trauma-induced intubation [adjusted odds ratio (aOR), 0.329; 95% confidence interval (CI), 0.117-0.927; p=0.036], and stent length <50 mm (aOR, 0.274; 95% CI, 0.130-0.578; p=0.001) were associated with a decreased risk of restenosis.

CONCLUSION

Trauma-induced intubation and stent length were associated with successful stent removal.

Diagnostic performance of digital tomosynthesis to evaluate silicone airway stents and related complications

Background

Digital tomosynthesis (DTS) is an imaging technique with benefits in reconstructing sequential cross-sectional images. We evaluated the diagnostic performance of DTS for silicone airway stents and stent-related complications in patients who underwent bronchoscopic intervention.

Methods

This retrospective study included patients who underwent bronchoscopic intervention after chest radiography (CXR) and DTS examinations from September 2013 to August 2020. The interval between CXR, DTS, and bronchoscopic intervention was a maximum of 10 days. CXR and DTS images were evaluated using a bronchoscopic view as a reference. We calculated the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value for assessing the diagnostic performance.

Results

The total CXR, DTS, and bronchoscopic intervention-matching datasets comprised 213 cases from 119 patients and, silicone stents were present in 167 of them. The ability of DTS to detect silicone stents was better than that of CXR (sensitivity, 92.8% vs. 71.3%, P<0.001). Of the 167 cases with silicone stents, 53 experienced stent migration and 121 experienced stent obstructions due to granulation tissue or fibrosis. The sensitivity for detecting stent migration was also higher with DTS than with CXR (45.3% vs. 24.5%, P=0.025). The sensitivity for detecting the stent obstruction was better with DTS than with CXR (64.5% vs. 19.0%, P<0.001).

Conclusions

DTS was more sensitive and accurate in revealing silicone airway stents and silicone stent-related complications than CXR. However, there were limitations in confirming stent migration and obstruction with DTS due to granulation tissue growth and fibrosis.

Surgical repair for post-tuberculosis tracheobronchial stenosis

AIM

Post-tuberculosis tracheobronchial stenosis is rare but one of the most dangerous complications of tracheobronchial tuberculosis. Balloon dilatation, stent insertion, laser photoresection, argon plasma coagulation, and cryotherapy are some of the initial treatments recommended for mild to moderate cases. Here, we report a case series of patients who underwent segmental resection and end-to-end anastomosis for bronchial stenosis and a sliding technique for severe and long-segment tracheal stenosis.

METHODS

We retrospectively reviewed the medical records of patients with post-tuberculosis tracheobronchial stenosis operated on in our thoracic surgery department. Of the 7 cases that were treated, two had severe tracheal stenosis stretching over 50% of the tracheal length, one was operated on using resection and end-to-end anastomosis, and the other had sliding tracheoplasty. The other 5 cases of bronchial stem stenosis were treated with segmental resection and end-to-end anastomosis.

RESULTS

All five patients with bronchial stenosis had a good outcome; the ipsilateral lung was well ventilated and respiratory function was good. One patient with tracheal stenosis, treated with segmental resection and end-to-end anastomosis, died after the surgery, and the other patient, treated with slide tracheoplasty, had a good recovery.

CONCLUSION

The treatment plan for patients with post-tuberculosis tracheobronchial stenosis should be on a patient-by-patient basis. Sliding tracheoplasty can be a treatment option in patients with long-segment tracheal stenosis.

Angulated Stents-A Novel Stent Improvisation to Manage Difficult Post-tuberculosis Bronchial Stenosis

Post-tuberculosis bronchostenosis (PTBS), a complication of endobronchial tuberculosis is currently treated by bronchial stenting. However, in cases of angulated bronchial stenoses, difficulty is often encountered in stent insertion and maintenance, resulting in stent migration, granulation tissue overgrowth, and restenosis. To accommodate the angulated alignment of the stenosis, we devised an "angulated stent"-a novel improvisation of the conventional stent via splicing and suturing to achieve a resultant angulated shape. A retrospective review was undertaken to evaluate the performance of this stent. Among 283 PTBS patients who underwent interventional bronchoscopy at our center from 2004 to 2014, 21 were treated with at least one angulated stent. Clinical outcomes, including the stenting duration were investigated. After a median follow-up of 26 months, stent removal was successful in 7 (33.3%) out of 21 patients. In patients managed with angulated stents, the median duration to stent change or eventual removal was longer than those treated with straight tube stents (392 days vs. 86 days; p < 0.05). Angulated stents are a feasible treatment option in patients with angulated PTBS by reducing complications and prolonging the stent-changing interval.

Ventilation strategy and anesthesia management in patients with severe tracheal stenosis undergoing urgent tracheal stenting

BACKGROUND

Stenting of airway stenosis is a common procedure in specialized centers. The aim of this study was to summarize our clinical experience in ventilation strategy and anesthesia management of patients undergoing urgent tracheal stenting.

METHODS

Clinical data of 22 patients with severe tracheal stenosis who underwent urgent endoscopic placement of a tracheal stent during a 2-year period were retrospectively reviewed. The efficacy and safety of different ventilation strategies and veno-arterial extracorporeal membrane oxygenation (ECMO), individualized based on the cause and location of tracheal narrowing, were evaluated.

RESULTS

Sufficient ventilation was successfully established in all patients; ECMO was used in five patients with stenosis in the mid-trachea who were unable to tolerate conventional intubation; a laryngeal mask airway (LMA) was used in five patients with post-intubation tracheal stenosis; a cuffed tracheal tube was used in eight patients with lower tracheal stenosis; and low-frequency jet ventilation in rigid bronchoscopy was used in four patients with mid- or lower tracheal stenosis. Tracheal stents were successfully placed and there were significant improvements in dyspnea. There were significant increases in the partial pressure of carbon dioxide in patients ventilated with the LMA and cuffed tracheal tube. There was no hypoxia during the operative period.

CONCLUSION

Establishment of effective airway ventilation in patients with severe tracheal stenosis should be based on the cause, location, and severity of tracheal narrowing. Veno- arterial ECMO may be considered in patients with severe stenosis, if they are judged unable to tolerate conventional ventilation or jet ventilation.

Tuberculous tracheobronchial stenosis: avoiding resection-when less is more

A case of tracheobronchial stenosis due to tuberculosis in a young woman is presented. Compromised pulmonary function due to near-total obstruction of the proximal left main bronchus was diagnosed. Treatment options included surgical resection, endobronchial dilation or stenting, and argon photocoagulation. An approach was chosen to address symptoms without aggressive resection or commitment to stenting. She remains monitored and, while possibly committed to future intervention, no bridges have been burned with respect to more definitive and invasive therapies. We propose this "less is more" initial approach in all patients when possible. Reserving the more aggressive alternatives for high-risk surgical candidates and those that have been unresponsive to lesser procedures.

A new removable airway stent

Background

Malignant airway obstruction is a feared complication and will most probably occur more frequently in the future because of increasing cancer incidence and increased life expectancy in cancer patients. Minimal invasive treatment using airway stents represents a meaningful and life-saving palliation. We present a new removable airway stent for improved individualised treatment.

Methods

To our knowledge, the new airway stent is the world's first knitted and uncovered self-expanding metal stent, which can unravel and be completely removed. In an in vivo model using two anaesthetised and spontaneously breathing pigs, we deployed and subsequently removed the stents by unravelling the device. The procedures were executed by flexible bronchoscopy in an acute and a chronic setting – a ‘proof-of-principle’ study.

Results

The new stent was easily and accurately deployed in the central airways, and it remained fixed in its original position. It was easy to unravel and completely remove from the airways without clinically significant complications. During the presence of the stent in the chronic study, granulation tissue was induced. This tissue disappeared spontaneously with the removal.

Conclusions

The new removable stent functioned according to its purpose and unravelled easily, and it was completely removed without significant technical or medical complications. Induced granulation tissue disappeared spontaneously. Further studies on animals and humans are needed to define its optimal indications and future use.