Airway Stents Research Articles

A novel ex vivo tracheobronchomalacia model for airway stent testing and in vivo model refinement

ObjectivesWe sought to develop an ex vivo trachea model capable of producing mild, moderate, and severe tracheobronchomalacia for optimizing airway stent design. We also aimed to determine the amount of cartilage resection required for achieving different tracheobronchomalacia grades that can be used in animal models. MethodsWe developed an ex vivo trachea test system that enabled video-based measurement of internal cross-sectional area as intratracheal pressure was cyclically varied for peak negative pressures of 20 to 80 cm H2O. Fresh ovine tracheas were induced with tracheobronchomalacia by single mid-anterior incision (n = 4), mid-anterior circumferential cartilage resection of 25% (n = 4), and 50% per cartilage ring (n = 4) along an approximately 3-cm length. Intact tracheas (n = 4) were used as control. All experimental tracheas were mounted and experimentally evaluated. In addition, helical stents of 2 different pitches (6 mm and 12 mm) and wire diameters (0.52 mm and 0.6 mm) were tested in tracheas with 25% (n = 3) and 50% (n = 3) circumferentially resected cartilage rings. The percentage collapse in tracheal cross-sectional area was calculated from the recorded video contours for each experiment. ResultsEx vivo tracheas compromised by single incision and 25% and 50% circumferential cartilage resection produce tracheal collapse corresponding to clinical grades of mild, moderate, and severe tracheobronchomalacia, respectively. A single anterior cartilage incision produces saber-sheath type tracheobronchomalacia, whereas 25% and 50% circumferential cartilage resection produce circumferential tracheobronchomalacia. Stent testing enabled the selection of stent design parameters such that airway collapse associated with moderate and severe tracheobronchomalacia could be reduced to conform to, but not exceed, that of intact tracheas (12-mm pitch, 0.6-mm wire diameter). ConclusionsThe ex vivo trachea model is a robust platform that enables systematic study and treatment of different grades and morphologies of airway collapse and tracheobronchomalacia. It is a novel tool for optimization of stent design before advancing to in vivo animal models.

External beam radiotherapy inhibits stent related granulation hyperplasia in rabbit trachea

Endobronchial stent exacerbates the formation of granulation tissue. Radiotherapy maybe a durable treatment option for granulation hyperplasia. In this study, we explore the results of external beam radiotherapy (EBRT) for granulation hyperplasia after airway stent placement. A total of 30 New Zealand rabbits were assigned in three groups, Control group (n = 12), low dosage (LD, 12 Gy in 4 fractions and twice a week) group (n = 9) and high dosage (HD, 20 Gy in 4 fractions and twice a week) group (n = 9). Post-stenting 1 week, LD and HD group started to receive EBRT. Bronchoscopy, Haematoxylin–eosin (HE), Masson’s trichrome (MTS), Safranin O (SO) and immunohistochemical (IHC) staining protocols were performed to evaluate the histopathological changes of trachea. A total of 30 stents were successfully implanted in 30 rabbits. No procedure-related death and complications happened. Post-stenting 4 w, 8 w and 12 w, the ventilate area ratio (VAR) and qualitative histological scoring (QHS) in the LD group and HD group lower than the Control group. Post-stenting 12w, the immunohistochemical results revealed that the positive percentage of TGF-β and VEGF in the LD group and HD group were lower than the Control group. In conclusion, the present study investigated the efficacy of EBRT in reducing stent related granulation tissue formation in the rabbit trachea. Higher dosage EBRT with a better result in inhibiting granulation hyperplasia.

Laryngotracheal Reconstruction Outcomes in Children Born Extremely Premature.

There has been a notable increase in the number of neonates born 28 weeks gestational age or younger in the United States. Many of these patients require tracheostomy early in life and subsequent laryngotracheal reconstruction (LTR). Although extremely premature infants often undergo LTR, there is no known study to date examining their post-surgical outcomes. To compare decannulation rates, time to decannulation and complication rates between LTR patients born extremely premature to those born preterm and term. We identified 179 patients treated at a stand-alone tertiary children's hospital who underwent open airway reconstruction from 2008 to 2021. A Chi Squared test was used to detect differences in categorical clinical data between the groups of patients. A Mann-Whitney test was used to analyze continuous data within these same groups. Time to decannulation analysis was performed using Kaplan Meier analysis and evaluated with log-rank and Cox proportional hazards regression. Children born extremely premature were more likely to incur complications following LTR (OR = 2.363, p = 0.005, CI 1.295-4.247). There was no difference in time to decannulation (p = 0.0543, Log-rank) or rate of decannulation (OR = 0.4985, p = 0.05, CI 0.2511-1.008). Extremely premature infants were more likely to be treated with an anterior and posterior grafts (OR = 2.471, p = 0.004, CI 1.297-4.535) and/or an airway stent (OR = 3.112, p < 0.001, CI 1.539-5.987). Compared with all other patients, extremely premature infants have equivalent decannulation success, but are at an increased risk for complications following LTR. 3 Laryngoscope, 133:3608-3614, 2023.

(895) Airway Stenting for Tracheal Anastomotic Dehiscence after a Combined Heart-Lung Transplant

(895) Airway Stenting for Tracheal Anastomotic Dehiscence after a Combined Heart-Lung Transplant

Extracorporeal membrane oxygenation in critical airway interventional therapy: A review.

Extracorporeal membrane oxygenation (ECMO) is widely used during refractory cardiac or respiratory failure, and some case reports described ECMO utilization in critical airway interventional therapy. Eligible reports about patients receiving airway interventional therapy under ECMO were retrieved from Web of Science, Embase, Medline, and Cochrane databases up to 1 August 2022. Forty-eight publications including 107 patients who underwent ECMO for critical airway problems met the inclusion criteria. The critical airway problem that was reported the most was tumor-associated airway obstruction (n = 66, 61.7%). The second most reported etiology was postoperative airway collapse or stenosis (n = 19, 17.8%). The main interventional therapies applied were airway stent placement or removal (n = 61, 57.0%), mass removal (n = 22, 20.6%), and endotracheal intubation (n = 12, 11.2%) by bronchoscopy. The median ECMO duration was 39.5 hours. Eleven patients had ECMO-associated complications, including seven cases of airway hemorrhage, one case of arteriovenous fistula, one case of vein rupture and hematoma, one case of foot ischemia, and one case of neuropraxia of the cannulation site. In total, 91.6% of the patients survived and were discharged from the hospital. ECMO appears to be a viable form of life support for patients undergoing interventional therapy for critical airway problems.

A single-tube-braided stent for various airway structures.

Background: Airway stent has been widely used in airway procedures. However, the metallic and silicone tubular stents are not customized designed for individual patients and cannot adapt to complicated obstruction structures. Other customized stents could not adapt to complex airway structures with easy and standardized manufacturing methods. Object: This study aimed to design a series of novel stents with different shapes which can adapt to various airway structures, such as the "Y" shape structure at the tracheal carina, and to propose a standardized fabrication method to manufacture these customized stents in the same way. Methods: We proposed a design strategy for the stents with different shapes and introduced a braiding method to prototype six types of single-tube-braided stents. Theoretical model was established to investigate the radial stiffness of the stents and deformation upon compression. We also characterized their mechanical properties by conducting compression tests and water tank tests. Finally, a series of benchtop experiments and ex vivo experiments were conducted to evaluate the functions of the stents. Results: The theoretical model predicted similar results to the experimental results, and the proposed stents could bear a compression force of 5.79N. The results of water tank tests showed the stent was still functioning even if suffering from continuous water pressure at body temperature for a period of 30days. The phantoms and ex-vivo experiments demonstrated that the proposed stents adapt well to different airway structures. Conclusion: Our study offers a new perspective on the design of customized, adaptive, and easy-to-fabricate stents for airway stents which could meet the requirements of various airway illnesses.

Central airway stenting in oncology

Introduction. Malignant central airway obstruction and malignant tracheoesophageal fistula in the context of tumor development are potentially life-threatening conditions which usually require immediate intervention. Airway stenting is one of the safest and most effective methods of airway patency restoration in patients with malignant obstruction of the central airways and restoration of continuity in patients with malignant tracheoesophageal fistula.Aim. To evaluate the significance of self-expandable metal stents in palliative treatment of patients with malignant central airway obstruction and malignant tracheoesophageal fistula.Materials and methods. Between 2017 and 2021 at the N. N. Blokhin National Medical Research Center of Oncology, 55 patients were observed and treated and underwent trachea stenting per the results of bronchoscopy in combination with esophagogastroduodenoscopy. The 1st group included 25 patients with malignant tracheoesophageal fistulas, the 2nd group included 30 patients with malignant central airway obstruction.Results. In the 1st group, stenting was successful in 25 (100 %) cases which allowed to adequately seal the fistula. Stent migration was observed in 1 (4 %) patient with tracheoesophageal fistula in the context of stenosing cancer of the thoracic esophagus. In the 2nd group, stenting was successful in 30 (100 %) cases. Stent migration was not observed in this patient group. In both groups, there were no complications after stent implantation. Installation of tracheal stent allowed to improve patients’ quality of life and provide a possibility for successful special treatment through low-trauma manipulation.Conclusion. According to the obtained data, endoscopic trachea stenting is the most important method of palliative treatment of tumor-related trachea lesions with development of tracheoesophageal fistulas, malignant central airway obstructions and associated sub- and decompensated pulmonary insufficiency.

Forbearance with endobronchial stenting: cognisance before conviction.

Endobronchial stenting is an important aspect of the practice of interventional pulmonology. The most common indication for stenting is the management of clinically significant airway stenosis. The list of endobronchial stents available on the market continues to grow. More recently, patient-specific 3D-printed airway stents have been approved for use. Airway stenting should be considered only when all other options have been exhausted. Due to the environment of the airways and the stent-airway wall interactions, stent-related complications are common. Although stents can be placed in various clinical scenarios, they should only be placed in scenarios with proven clinical benefit. The unwarranted placement of a stent can expose the patient to complications with little or no clinical benefit. This article reviews and outlines the key principles of endobronchial stenting and important clinical scenarios in which stenting should be avoided.

CODE BLUE in a patient with tracheal stent: Are we fully equipped?

Sir, Airway stents have long been used to maintain luminal integrity of compromised airway in case of obstruction and malignancy.[1] The complications associated with airway stent placement are malposition, haemorrhage, airway rupture during placement, migration, impaction, formation of granulation tissue, and stent fracture.[2] We present here a challenging case of an airway emergency in a patient with a tracheal stent inserted for a malignancy. A 29-year-old woman diagnosed with adenoid cystic carcinoma of trachea 2 years back had undergone debulking of tumor, tracheal stenting with a metallic stent, and chemo-radiotherapy elsewhere. On the second day of admission, CODE BLUE was activated in view of acute onset biphasic stridor, with air hunger and low oxygen saturation. Despite resuscitation measures, the patient had persistent tachycardia, tachypnea, and hypoxia with non-rebreathing mask (15 L/min of O2). A review of Computed Tomography (CT) neck revealed a tracheal narrowing 1.7 cm distal to vocal cords with narrowest diameter of 6 mm [Figure 1a], complicating an imminent intubation for the patient. She was pre-oxygenated with a non-invasive ventilation mask. Intravenous boluses of fentanyl 75 mcg, muscle relaxant (suxamethonium 100 mg) was given and intubated with a 5.0 mm ID cuffed endotracheal (ET) tube through direct laryngoscopy. A chest x-ray confirmed the position of the ET tube but it fell short of bypassing the tracheal stent, which was reflected in decreased tidal volumes and increased peak pressure. As the length of the 5.0 mm ET tube (23 cm) was not enough to bypass the stent, we had to increase the length by rail roading another 6.5 mm ID tube at the distal end, after removing the connector [Figure 1b]. This step significantly improved the tidal volumes (350-400 ml) without much rise in peak pressure with marked improvement in the oxygenation of patient in the blood gas analysis. Patient underwent bronchoscopic biopsy and excision of mass around the stent after putting on veno-venous extracorporeal membrane oxygenation for oxygenation. Post-procedure ET tube was removed after suctioning and intubated with 7.0 mm ID ET tube for postoperative ventilation and eventually extubated.Figure 1: (a) image showing CECT neck with tracheal stent in situ. (b) image showing the proximal end of 6.5 mm ID tube is cut and railroaded over 5.0 mm ID tube to increase the lengthSecuring airway in an in-hospital CODE blue needs quick thinking and swift action. This case highlights a unique situation where a tracheal stent precluded a “conventional intubation.” A tracheostomy could damage the stent and a supraglottic airway device risked aspiration.[3] A fibre-optic bronchoscope is essential and the best available option to ensure correct position of the tube within the stent or just above the stent. It can also avoid stent-related complications but is not readily available everywhere.[4] No formal guidelines are available in terms of airway management with tracheal stents in situ. A literature search also revealed paucity of data with regard to management in similar case scenarios. Microlaryngeal surgery (MLS) tubes can be made available in the CODE BLUE kits anticipating such scenarios, as they are longer than conventional ET tubes with same internal diameter.[5] This case though uncommon highlights the need to incorporate airway management in cases of tracheal stents as part of our teaching curriculum. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Broadening the scope for three-dimensional printed airway stents.

The ideal airway stent is still not available. Indications for 3D stents currently are limited to rare cases. Therefore, further research is required to investigate whether personalised airway stents will perform better than conventional stents. https://bit.ly/3GLjPa4.

Determination of patient-specific airway stent fit using novel 3D reconstruction measurement techniques: a 4-year follow-up of a patient.

Managing complex benign airway disease is a major challenge in interventional pulmonology. With the introduction of additive manufacturing in the medical field, patient-specific (PS) implants are an innovate prospect for airway management. Historically, stents were oversized to resist migration. However, the optimal degree and impact of stent oversizing remains unclear. The ability to design stents based on computed tomography (CT) invites opportunity to understand sizing. Here, we report a novel three-dimensional (3D) image reconstruction tool to quantify fit repeatedly over time. Analysis of CT imaging before and after successive stent implants in a single patient with different areas of stenosis and malacia was done. Nine PS airway stents over 4 years (five left mainstem and four right mainstem) were studied. The distance between the airway model and stent was calculated. The CT images were correlated to stent designs in CloudCompare software (v2.10-alpha) for novel analysis. Heat map was exported depicting the distances between the airway and the stent to the clinician's prescribed stent model. Corresponding histograms containing distances, mean, and standard deviation were reported. It is possible to measure stent fit based on heat map quantification on patient imaging. Observation of the airway over time and stent change suggests that the airway became more open over time requiring increased stent diameters. The ability to design and measure stent fit over time can help quantify the utility and impact of PS silicone airway stent. The airway appears to display plasticity such that there is notable change in stent prescription over time.

Airway stent intervention in a high-volume center: safe procedures and educational perspectives.

Airway intervention, including stenting, can rapidly improve a patient's respiratory condition, but the procedure requires highly specialized techniques and expertise. Therefore, educating young endoscopists and passing on the techniques are major issues. However, the best way to educate new doctors on these techniques remains unclear. This study analyzed our educational system for airway intervention and its outcomes. Patients who underwent airway intervention regarding airway stents under general anesthesia in our department between January 2010 and September 2023 were included. The outcomes of interventions related to airway stents in our hospital were evaluated retrospectively, including from an educational perspective. A total of 96 patients (76 undergoing stenting for airway stenosis, 8 stenting for airway-esophageal fistula, and 12 stent removal) were analyzed. The median experience level of the main physician was 5 (range, 1-17) years, and that of the supervising physician was 18 (range, 5-23) years. The median number of physicians who participated in the interventions was four. A rigid bronchoscope was used in 86.5% of cases. The procedure success rate was 95.8%. Intraoperative complications occurred in 8.3% and postoperative complications in 10.5% of cases, and there was 1 procedure-related death (1.3%). In the analysis of factors related to the development of complications, the years of experience of the main physician had no influence. These findings indicate that our method of airway intervention is safe. Young endoscopists were able to master the technique by gaining experience under the supervision of experts.

Bronchoscopic interventions for bronchopleural fistulas

Bronchopleural fistula is a potentially fatal disease most often caused after pneumonectomy. Concomitant problems such as pulmonary infection and respiratory failure are typically the main contributors to patient mortality because of the improper contact between the bronchial and pleural cavity. Therefore, bronchopleural fistulas need immediate treatment, which requires the accurate location and timely closure of the fistula. Currently, bronchoscopic interventions, because of their flexibility and versatility, are reliable alternative therapies in patients for whom surgical intervention is unsuitable. Possible interventions include bronchoscopic placement of blocking agents, atrial septal defect (ASD)/ventricular septal defect (VSD) occluders, airway stents, endobronchial valves (EBVs) and endobronchial Watanabe spigots (EWSs). Recent developments in mesenchymal stem cells (MSCs) transplantation technology and three-dimensional (3D) printed stents have also contributed to the treatment of bronchopleural fistula, but more research is needed to investigate the long-term benefits. This review focuses on the effectiveness of various bronchoscopic measures for the treatment of bronchopleural fistula and the directions for future development.

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

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. 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. 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. 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.

A prediction model for risk of low oxygen saturation in patients with post-tuberculosis tracheobronchial stenosis during bronchoscopy

Background: Low oxygen saturation (LOS) is a frequent occurrence for patients with post-tuberculosis tracheobronchial stenosis (PTTS) during bronchoscopic procedures. However, there are currently no systematic assessment tools to predict LOS risk in PTTS patients during bronchoscopy. Objectives: This study aimed to develop an effective preoperative predictive model to guide clinical practice. Design: Retrospective cohort study. Methods: Data was retrospectively collected from PTTS patients who underwent bronchoscopic interventions between January 2017 and December 2022. Among all patients included in this study, patients between January 2017 and December 2021 were used as training cohort for the logistic regression model, and patients between January 2022 and December 2022 were utilized as validation cohort for internal validation. We used consistency index (C-index), goodness-of-fit test and calibration plot to evaluate the model performance. Results: A total of 465 patients who met the inclusion criteria were enrolled in the study. The overall incidence of LOS was 26.0% (121/465). Comorbidity, degree of stenosis, bronchoscopist level, thermal ablation therapy, balloon dilation, and airway stenting, as independent risk factors for the presence of LOS, were used to construct the nomogram prediction model. The C-index of training cohort was 0.827 (95% CI, 0.786–0.869), whereas that of validation cohort was 0.836 (95% CI, 0.757–0.916), combining with the results of the calibration plot and goodness-of-fit test, demonstrating that this model had good predictive ability. Conclusion: The predictive model and derived nomogram with good predictive ability has been developed to preoperatively predict the risk of LOS in PTTS patients during bronchoscopy, allowing for individualized interventions for high-risk patients.

Effect of Bronchoscopic Spray Cryotherapy and Ultra-low Temperature on Physical Properties of Metallic and Silicone Airway Stents.

Bronchoscopic spray cryotherapy (SCT) is utilized in the field of interventional pulmonology for treating benign and malignant airway stenosis as a standard tool to maintain airway patency. Stent-related complications include tumor overgrowth, granulation tissue, and epithelialization. Thermal ablation can have a limited role in such scenarios due to the risk of airway fire and damage to the existing stent. SCT is a potential therapy using ultra-low temperatures that can allow stents to remain in place during treatment. However, there has been no study demonstrating the safety of SCT on the integrity and physical properties of tracheobronchial stents. We report the results of the first study demonstrating the safety of SCT utilized to treat stent-associated granulation or malignant airway disease. The aim of this study was to demonstrate the effects of SCT on the physical properties of airway stents in an ex vivo environment. Various types of airway stents were subjected to multiple intervals of SCT for up to 30 seconds, and then the cycle was repeated 3 times. After every cycle, we compressed the stents to 60% of their original size, and compression and expansion force data was collected immediately after, at 3-minute and 5-minute intervals, and compared with the baseline readings. There was no significant change in the association between diameter and compression/expansion force, including any derangement in returning to the original diameter or any physical damage to any of the stents even after 3 prolonged SCT sessions of 30 seconds. Our study provides the first evidence that the use of SCT in conjunction with existing silicone/metal stents is feasible and does not cause any physical damage to the stents or alters their ability to maintain the original diameter.

Idiopathic double tracheal Stenosis mimicking asthma: a case report

Idiopathic tracheal stenosis (Idio-SS) is an extremely rare disease. Its diagnosis is of exclusion and could be misdiagnosed as asthma. Herein, we report the case of a 39-year-old woman who had been treated for asthma for several months. She has no history of endotracheal intubation or granulomatous disease. Flexible fiberoptic bronchoscopy and thoracic computed tomography revealed double tracheal stenosis. The patient had rigid bronchoscopy; the upper tracheal stenosis was dilated with insertion of a silicone airway stent at the level of the distal stenosis. The diagnosis of idiopathic stenoses was made according to the clinico-radiological features. Symptoms were completely relieved and no recurrence was observed after one year of follow-up. This case highlights the importance of clinical suspicion and early diagnosis of Idio-SS in patients with unexplained wheezing and dyspnea. It also illustrates the role of endoscopic procedures in this situation.

Risk Factors for Desaturation in Anesthetic Management During Airway Stenting.

Airway stenting involves a stent being inserted into a stenotic site in the airway. In patients with airway stenosis, the airway is the surgical field; therefore, anesthetic management is challenging, and avoiding hypoxia is important. Limited information is available on the anesthetic management of airway stenting. Risk factors for oxygen desaturation during airway stenting remain unknown. The present study was conducted to retrospectively examine patients who underwent airway stenting during a specific period and identify risk factors associated with oxygen desaturation. We performed univariate and multivariate analyses. The main evaluation items in a multivariate analysis were risk factors for desaturation (SpO2 ≤ 90%). Body mass index, preoperative orthopnea, the stenotic site of the airway, and severity of stenosis were selected for clinical usefulness. We analyzed 302 patients who underwent airway stenting at our hospital between July 2011 and June 2014 under general anesthesia with controlled ventilation. Total intravenous anesthesia with propofol target-controlled infusion and remifentanil was performed. Clinical data were extracted from electronic anesthetic records. The incidence of desaturation (SpO2 ≤ 90%) was 18.5% (56 out of 302 cases). Preoperative orthopnea (OR, 3.06)and stenosis distal to the bronchus (OR, 3.31) were identified as risk factors for desaturation in a multivariate analysis. We herein identified risk factors for desaturation during airway stenting. Anesthetic plans need to be carefully considered for patients with these risk factors.

Airway Stent in Lung Cancer: A Narrative Literature Review

Lung cancer complications are the leading cause of death in lung cancer patients. This study aimed to describe the prevalence of stent placement, indications for stent placement, success and complication rates, and prognosis of airway stent placement in patients with lung cancer. Malignant central airway obstruction (MCAO) is one of the significant complications. Insertion of airway stent can restore airway patency in more than 90% of patients with MCAO. Airway stent placement is indicated in patients with extrinsic lesions, obstruction of ≥ 50%, have patent airway below the obstruction, and are not in the terminal state. The technical success was reported to be very high and consistent with the range of 95-100%. Early complications were relatively rare; however, up to 87% of long-term complications were reported. Stent placement is a risk factor for lower respiratory tract infection, an adverse prognostic factor in lung cancer survival. Airway stents should be indicated and used with caution and discretion. With the advancement and development of technology, various materials and types of airway stents are being developed to minimize adverse outcomes.

Airway stenting using Ultraflex for central airway stenosis due to lung cancer: A case report

Airway stenting using Ultraflex for central airway stenosis due to lung cancer: A case report