Long-term follow-up of self-expandable metallic stents in benign tracheobronchial stenosis: a retrospective study

Systematic review comparing the efficacy and safety of covered and uncovered self-expanding metal stents in benign airway stenosis

BACKGROUND

Current United States Food and Drug Administration (FDA) guidelines established since 2005 recommend the usage of silicone stents over metal stents due to the risk of complications associated with the older generation of uncovered stents. Yet, with the advancement of technology, novel innovations of self-expanding metal stents (SEMS) have revolutionized the treatment of benign airway stenosis (BAS), where the insertion of SEMS is known to be easier than silicone stents.

AIM

To compare the efficacy and safety of covered SEMS against uncovered SEMS, and thereafter propose more direct trials comparing covered SEMS against silicone stents for consideration of revision of current FDA guidelines.

METHODS

A comprehensive literature review of MEDLINE and EMBASE was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Of 3002 articles, 64 publications met the eligibility criteria with a total of 900 patients (468 covered SEMS, 432 uncovered SEMS). The collected data were analyzed using Statistical Package for the Social Sciences version 11.5.

RESULTS

Covered SEMS showed a higher success rate of insertion (98.6% vs 88.2%) and lower complication rates of infection (1.3% vs 13.2%), restenosis (1.5% vs 10.6%), stent fracture (2.6% vs 7.4%), bleeding (0% vs 5.8%), and pneumothorax (0% vs 2.8%) compared to uncovered SEMS. However, covered SEMS compared to uncovered SEMS showed higher complication rates of stent migration (12.4% vs 6.9%) and granulation tissue formation (26.5% vs 20.1%).

CONCLUSION

Our study suggests that covered SEMS are an effective, safe, and viable option in the treatment of BAS. Thus, further consideration regarding the utilization of covered SEMS over other forms of stent types is appropriate.

Airway stenosis: classification, pathogenesis, and clinical management

Airway stenosis (AS) is a fibroinflammatory disease characterized by abnormal activation of fibroblasts and excessive synthesis of extracellular matrix, which has puzzled many doctors despite its relatively low prevalence. Traditional treatment such as endoscopic surgery, open surgery, and adjuvant therapy have many disadvantages and are limited in the treatment of patients with recurrent AS. Therefore, it is urgent to reveal the pathogenesis of AS and accelerate its clinical transformation. Based on the discovered pathogenesis, including fibrosis, inflammation, epithelial-mesenchymal transition, metabolic reprogramming, microbiome, genetic susceptibility, and other mechanisms, researchers have developed a series of treatments, such as drug therapy, gene therapy, stem cell therapy, growth factor therapy, protein therapy, and photodynamic therapy. This review introduces the classification of AS, explores the existing pathogenesis and preclinical treatments developed based on the pathogenesis, and finally summarizes the current clinical management. In addition, the prospect of exploring the interaction between different types of cells and between microorganisms and cells to identify the intersection of multiple mechanisms based on single-cell RNA sequencing, 16S rRNA gene sequencing and shotgun metagenomic sequencing is worth looking forward to.

Diagnosis and surgical treatment of tracheal cicatricial stenoses: literature review

OBJECTIVE

Aim: To study of the data about the results of tracheal cicatricial stenoses treatment with the goal of further improvement of its results on the basis of diagnosis enhancing, identification of factors of prognosis of the disease and by conducting a differential analysis of tactics of surgical treatment with the use of minimally invasive interventions.

PATIENTS AND METHODS

Materials and Methods: We have identified contemporary literature sources on the topic of modern directions of treatment of tracheal cicatricial stenoses and their complications. The studied material has been summarized and represented in the form of literature review in this article.

CONCLUSION

Conclusions: To increase the quality of treatment of patients with tracheal cicatricial stenoses and their surgical complications an important role is played by objective formation of groups at risk of complications development and prognosis of the disease dynamics. Successful solution of the problem is related mostly to the highly informative diagnostics, reliable determination of severity of disease, as well creation of multidirectional classification of tracheal cicatricial stenoses. These issues may not be considered completely solved, they require further study. All of the above dictates search of new effective methods of treatment of the indicated pathology and proves relevance of the topic. The stated information emphasizes necessity of improvement of surgical tactics of patients with tracheal cicatricial stenoses.

Novel approach for tracheal resection in Morquio a syndrome with end-stage critical airway obstruction: a UK case series

BACKGROUND

Mucopolysaccharidosis (MPS) type IVA is a rare lysosomal storage disorder caused by aberrations of the N-acetyl-galactosamine-6-sulfatase (GALNS) enzyme. MPS IVA is associated with a wide gamut of respiratory and airway disorders that manifest in a continuum of severity. In individuals exhibiting severe phenotypic expression, terminal stages of the disease frequently culminate in life-threatening, critical airway obstruction. These manifestations of end-stage disease are engendered by an insidious progression of multi-level airway pathologies, comprising of tracheomalacia, stenosis, tortuosity and 'buckling'. Historically, the management of end-stage airway disease has predominantly leaned towards palliative modalities. However, contemporary literature has posited that the potential benefits of tracheal resection with aortopexy, performed under cardiopulmonary bypass (CPB), may offer a promising therapeutic option. In this context, we report on outcomes from patients undergoing a novel approach to tracheal resection that is combined with manubrial resection, leading to improved airway calibre, obviating the requisition for CPB.

RESULTS

In this study, seven patients with severe MPS IVA exhibited clinical symptoms and radiological evidence indicative of advanced airway obstruction. All patients had a tracheal resection with a partial upper manubriectomy via transcervical approach, which did not require CPB. The surgical cohort consisted of 5 females and 2 males, the median age was 16 years (range 11-19) and the median height was 105.6cm (range 96.4-113.4). Postoperatively, significant improvements were seen in forced expiratory volume in 1 second (FEV1), with a mean increase of 0.68 litres (95% CI: 0.45-0.91; SD: 0.20). Notably, other spirometry variables also showed meaningful improvements, providing evidence of positive treatment effects. Furthermore, there were no major long-term complications, and the procedure resulted in a significant enhancement in patient-reported domains using PedsQL (version 4.0).

CONCLUSIONS

This study represents the largest case series to date, on tracheal resection in patients with severe MPS IVA. Our findings demonstrate the effectiveness of the transcervical approach with partial manubriectomy for improving respiratory function and quality of life for individuals with advanced airway obstruction. Tracheal resection presents a promising treatment modality for severe cases of MPS IVA. Successful outcomes rely on meticulous multidisciplinary assessment, judicious decision-making, and appropriate timing of tracheal surgery. Further research and long-term follow-up studies are warranted to validate the long-term efficacy and safety of this approach.

Long-term outcomes of surgical reconstruction for post-tuberculosis tracheobronchial stenosis: a 7-year follow-up in a tuberculosis-endemic region

Background

Surgical reconstruction is often necessary for severe tracheobronchial stenosis resulting from tuberculosis (TB). However, the long-term efficacy of this approach remains unclear. This study investigated the safety and long-term outcomes of surgery for severe post-TB tracheobronchial stenosis.

Methods

We conducted a retrospective study of 48 patients with severe post-TB tracheobronchial stenosis who underwent surgical reconstruction between 2015 and 2018 in a TB-endemic region. Pre- and postoperative evaluations included Karnofsky performance status, modified Medical Research Council (mMRC) dyspnea scale, spirometry, chest computed tomography (CT) scan, and bronchoscopy. The primary outcome was intervention-requiring restenosis over the long term.

Results

The mean patient age was 30.6±9.9 years, with 91.7% females. Airway fibrosis was the predominant lesion (93.8%), affecting the bronchi (93.8%) and trachea (6.2%). All the patients underwent resection and anastomosis, and 56.2% required lobectomy. Postoperative complications occurred in 13 patients (27.1%), with prolonged air leaks being the most prevalent (12.5%). All complications resolved with conservative management. Significant improvements in performance status, dyspnea, and lung function were observed postoperatively and sustained for over 5 years. Within a median follow-up of 69 months, five cases of intervention-requiring restenosis occurred within the first year. The freedom from restenosis rate was 90% from 1 year onwards.

Conclusions

Surgical reconstruction is safe and effective in treating severe post-TB tracheobronchial stenosis. Larger studies are required to validate these findings.

Biodegradable tracheal stents: our ten-year experience with adult patients

BACKGROUND

Biodegradable (BD) stents made from polydioxanone have been used only in human airways. These stents combine the advantages of classical tracheal stents, and fewer side effects are expected due to their biocompatibility and their time-limited presence in airways. However, new clinical consequences have arisen. Here, the authors share their experiences with BD stents for tracheal indications, focusing on their safety and efficacy.

METHODS

This was a retrospective review of a collected database of adult patients who underwent implantation of biodegradable tracheal stents between September 2013 and December 2022 at the Department of Respiratory Medicine of the 1st Faculty of Medicine in Prague and Thomayer University Hospital. The indications included functionally significant nonmalignant tracheal stenosis and tracheomalacia. Self-expandable, biodegradable, polydioxanone tracheal stents manufactured by ELLA-CS Ltd. (Hradec Kralove, Czech Republic) were implanted during rigid bronchoscopy under general anaesthesia. All patients were followed up in the department and were provided with the necessary care. The main efficacy and safety parameters and relationships were analysed using descriptive statistics and Fisher´s exact, Wilcoxon and Kruskal‒Wallis tests.

RESULTS

A total of 65 stents were implanted in 47 adult patients. During the first two months after implantation, when adequate function was expected, the stent was found to be effective in 26 out of 39 patients who completed this period (66.7%). The clinical effectiveness reached 89.7%, as early restenoses were mostly mild and necessitated treatment in only 4 patients. The frequencies of significant mucostasis, migration and granulation tissue growth were 2.6%, 7.5% and 23.1%, respectively, during this period. Thirty-four participants completed the half-year follow-up period after the first or second stent insertion, and some were followed up beyond this period. Poor control of symptoms, the development of restenosis and the need for interventions were characteristic of this period as the stents degraded. Twenty-two patients who experienced remodelling or stabilization of the tracheal lumen achieved a stent-free state. Seven patients underwent subsequent surgical treatment.

CONCLUSIONS

BD stents are safe and provide adequate tracheal support until they begin to degrade. The use of BD stents necessitates close monitoring of patients and accurate treatment of possible restenosis.

TRIAL REGISTRATION

Based on project NT14146 - Biodegradable stents in the management of the large airways (2013-2015, MZ0/NT), registered on May 1, 2013, in the Research and Development and Innovation Information System of the Czech Republic and at ClinicalTrials.gov (reg. no. NCT02620319, December 2, 2015).

Burden, clinical features, and outcomes of post-tuberculosis chronic obstructive lung diseases

PURPOSE OF REVIEW

Post-tuberculosis lung disease (PTLD) is an increasingly recognized and debilitating consequence of pulmonary tuberculosis (PTB). In this review, we provide a comprehensive overview of PTLD with airflow obstruction (PTLD-AFO), focusing on its burden, pathophysiology, clinical manifestations, diagnostic methods, and management strategies.

RECENT FINDINGS

The relationship between PTLD and airflow obstruction is complex and multifactorial. Approximately 60% of the patients with PTLD have some spirometric abnormality. Obstruction is documented in 18-22% of PTLD patients. The host susceptibility and host response to mycobacterium drive the pathogenic mechanism of PTLD. A balance between inflammatory, anti-inflammatory, and fibrotic pathways decides whether an individual with PTB would have PTLD after microbiological cure. An obstructive abnormality in PTLD-AFO is primarily due to destruction of bronchial walls, aberrant healing, and reduction of mucosal glands. The most common finding on computed tomography (CT) of thorax in patients with PTLD-AFO is bronchiectasis and cavitation. Therefore, the 'Cole's vicious vortex' described in bronchiectasis applies to PTLD. A multidisciplinary approach is required for diagnosis and treatment. The disability-adjusted life-years (DALYs) attributed to PTLD represent about 50% of the total estimated burden of DALYs due to tuberculosis (TB). Patients with PTLD require comprehensive care that includes psychosocial support, pulmonary rehabilitation, and vaccination against respiratory pathogens. In the absence of trials evaluating different treatments for PTLD-AFO, therapy is primarily symptomatic.

SUMMARY

PTLD with airflow obstruction has considerable burden and causes a significant morbidity and mortality. However, many aspects of PTLD-AFO still need to be answered. Studies are required to evaluate different phenotypes, especially concerning Aspergillus -related complications. The treatment should be personalized based on the predominant phenotype of airflow obstruction. Extensive studies to understand the exact burden, pathogenesis, and treatment of PTBLD-AFO are needed.

Modified blade: an interventional option in rigid bronchoscopy for non-resectable benign tracheal stenosis

INTRODUCTION

Benign tracheobronchial stenosis is a abnormal tracheal lumen narrowing that may incur progressive dyspnea and life-threatening hypoxemia. There is no consensus on which patients should be treated with endoscopic or surgical method. This study investigates the outcomes of bronchoscopic dilatation in the treatment of benign tracheal stenosis using a device equipped with a blade to cut the stenotic lesions with dense fibrosis.

MATERIALS AND METHODS

The procedure was carried out in an operating room under general anesthesia. All patients were intubated with a Rigid Bronchoscope (RB) placed just above the stenosis. Through Rigid Bronchoscopy combined modalities were used as needed: radial incisions of the mucosal stenosis with blade at the levels of 4, 8 and 12 o'clock, with back and forth movements, then the stenotic area was dilated more easily with a rigid bronchoscope. Dilatation was performed by passing the RB of increasing diameter through stenotic areas and then Balloon dilatation of increasing diameter. There were no complications during the procedure.

RESULT

We conducted an observational, retrospective, single-centre study in the Thoracic Surgery Unit of the University of 'Luigi Vanvitelli' of Naples from November 2011 to September 2021. We included all consecutive patients with benign tracheal stenosis inoperable. During the study period, 113 patients were referred to our department with benign tracheal stenosis inoperable. 61 patients were treated with the blade. During the follow-up, a recurrence of the stenosis was observed in 8 patients in the first month and in 4 patients in the third month. Instead in the patients treated with the use of laser (52 patients), during the follow-up a recurrence was observed in 16 patients in the first month and in 6 patients in the third month; no patient relapsed after 6 months and after 1 year. Long term successful bronchoscopic management with blade was attained by 99% in simple and 93% in mixed stenosis and in complex type stenosis.

CONCLUSION

Our study underlines the importance of the use of the blade in bronchoscopic treatment as a valid conservative approach in the management of patients with inoperable benign tracheal stenosis as an alternative to the use of the laser, reducing the abnormal inflammatory reaction in order to limit recurrences.

Treatment of mixed and refractory post-tuberculosis tracheobronchial stenosis with L-shaped silicone stents: case series and a literature review

The two patients included in the study had mixed and refractory post-tuberculosis tracheobronchial stenosis (PTTS), having experienced unsuccessful interventional therapies such as balloon dilation and V-shaped stent placement before the operation. Following the secure placement of L-shaped silicone stents, examinations with a fiberbronchoscope during the first and third months post-operation revealed a significant reduction in bronchial mucosa inflammation for both patients. Additionally, the opening diameter of the upper and lower branch segments increased, and chest CT scans indicated a noticeable absorption of left pulmonary lesions. Three months post-operation, fiberbronchoscopy confirmed the stable fixation of the stent without any movement. The patients exhibited substantial improvements in pulmonary function, dyspnea index, and blood gas analysis, with no reported adverse complications. After 7 months, a follow-up fiberbronchoscope for one case revealed excellent stent fixation. Simultaneously, the chest CT scan indicated favorable re-expansion. The placement of L-shaped silicone stents proves effective in preventing displacement, alleviating airway stenosis or obstruction, and ensuring the safety and efficacy of PTTS treatment - particularly in cases where V-shaped silicone stent placement has failed. To our knowledge, this is the first study describing the L-shaped silicone stent in two patients with PTTS.

Analysis of clinical characteristics of 617 patients with benign airway stenosis

Introduction

Benign airway stenosis (BAS), namely airway narrowing caused by a variety of benign lesions, can lead to varying degrees of breathing difficulties and even death due to asphyxia. This study aimed to elucidate the clinical characteristics of BAS, including etiology, treatment and pathology, by analyzing the clinical data of BAS patients.

Methods

A retrospective analysis was conducted using the clinical data of 617 BAS cases from January 2017 to December 2022. The pathological characteristics of the tissues were assessed by hematoxylin-eosin (H&E) and Masson's staining. Besides, protein expression levels were determined by immunohistochemistry (IHC).

Results

A total of 617 patients were included (333 females [53.97%] and 284 males [46.03%]), with an average age of 48.93 ± 18.30 (range 14-87). Tuberculosis (n = 306, 49.59%) and trauma (n = 179, 29.02%) were the two leading etiologies of BAS, followed by airway foreign bodies (FB, n = 74, 11.99%), external compression (n = 25, 4.05%) and other etiologies (n = 33, 5.35%). Among 306 tuberculous tracheobronchial stenosis (TBTS) cases, most were females (n = 215, 70.26%), and TBTS mainly occurred in the left main bronchus (n = 97, 31.70%), followed by the right middle bronchus (n = 70 cases, 22.88%). The majority of TBTS patients (n = 259, 84.64%) were treated by interventional therapy. The condition of 179 BAS patients was ascribed to trauma, such as tracheal intubation (n = 92, 51.40%), tracheotomy (n = 69, 38.56%), injury (n = 15, 8.38%) and surgery (n = 3, 1.68%), which mostly took place in the trachea (n = 173, 96.65%). TAS patients mainly received interventional therapy (n = 168, 93.85%) and stent implantation (n = 47, 26.26%). The granulation tissues of BAS primarily featured inflammation, proliferation and fibrosis. IHC indicated the up-regulated expressions of transforming growth factor-β1 (TGF-β1), α-smooth muscle actin (α-SMA), collagen type I protein (COL-I) and vimentin, and the down-regulated expression of E-cadherin, which indicated fibrosis and epithelial-mesenchymal transition (EMT).

Conclusion

Tuberculosis was the main etiology, and trauma was the secondary etiology. The granulation tissues of BAS were characterized by inflammation, fibrosis and probably EMT. Comprehensive interventional therapy is an effective method of treating BAS.

Successful Hemostasis With Prolonged Balloon Inflation at the Proximal Site of the Coronary Perforation

Coronary perforation (CP) is a rare complication of percutaneous coronary intervention (PCI) and can lead to pericardial tamponade. Prolonged balloon inflation is a reasonable treatment for CP, but there is no standard recommendation on the preferable choice between the balloon site for prolonged balloon inflation (ie, proximal and in situ of the perforation). We present a rare case of successful prolonged balloon inflation at the proximal site of the CP after the failure of balloon inflation at the site of perforation. The patient developed CP during balloon inflation post-stent, rapidly progressing to cardiac tamponade. In situ prolonged balloon inflation (3 times) failed to close the CP, but proximal inflation could manage the CP. The take-home message from this case is that balloon expansion at the proximal site could be better than in situ of perforation in patients with CP after PCI.

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 30 days. 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.

Management of stent-related tracheoesophageal fistula in complex post-tuberculosis tracheobronchial stenosis: A case report

Background

The covered self-expandable metallic stents (SEMS) have been used to manage benign tracheobronchial stenosis, especially the complex post-tuberculosis (TB) tracheobronchial stenosis (PTTS) with cartilage destruction or malacia. This procedure could lead to stent-related tracheoesophageal fistula (TEF).

Case presentation

A 21-year-old woman, who had one covered Y-shaped SEMS inserted to manage complex PTTS 2 years ago, presented with dyspnea and frequent coughing on drinking water. The bronchoscopy confirmed extensive granulation tissue hyperplasia and a TEF on the upper edge of the covered SEMS. The covered SEMS was removed in three steps, and another fully covered Y-shape SEMS (Microtech Co., Ltd., Nanjing, China) was inserted to restore patency in the tracheobronchial tree and occlude the TEF orifice. Recombinant bovine basic fibroblast growth factor (rbFGF) (6,000 IU/time) was sprayed into and around the fistula through the V-System single-use cannula via the flexible bronchoscope every other week. The patient showed sustained clinical and radiographic improvement, and the TEF healed.

Conclusion

We presented a three-step bronchoscopic approach to managing a stent-related TEF in a patient with complex PTTS. Subsequently, regular bronchoscopic debridement of granulation tissue developing on the upper edge of SEMS is necessary to maintain the stent patency and reduce the risk of recurrent stent-related TEF. A fully covered SEMS associated with the local administration of rbFGF seems to offer an alternative simplified one-stage procedure for the temporary management of TEF combined with complex PTTS in non-surgical candidates.

A New Removable Helical Metallic Stent for the Treatment of Tracheomalacia in Children: Study in Pathological Animal Model

BACKGROUND

Congenital tracheomalacia is a pathology with no consensus of medical or surgical approach. The permanent nature and the major complications associated with metallic stents have limited their use over the years. The purpose of this study was to evaluate the feasibility of a helical stent design removal.

METHODS

Ten dogs diagnosed with tracheal collapse and treated with the helical stent were involved in the study. Animals were classified into three groups depending on stent indwelling time. Prior to the removal, endoscopic evaluation was performed to assess endothelization grade, mucous accumulation, and the presence of stenosis. During the removal, bleeding, fracture, or impossibility of removal were noted. After the removal, all macroscopic mucosal changes were recorded.

RESULTS

Technical success was 100%, without any complications. Complete epithelization of the stent was visualized in 7/10 animals. The removal procedure duration ranged from 2-12 min. At post-removal endoscopy, bleeding or epithelial damage, was visualized in any case. Stent fracture during removal occurred in one animal.

CONCLUSIONS

The removal of a metallic stent with spiral geometry is feasible, simple, and without complications, regardless of the degree of neo-epithelialization.

State of the Science in Tracheal Stents: A Scoping Review

OBJECTIVE

Recent material science advancements are driving tracheal stent innovation. We sought to assess the state of the science regarding materials and preclinical/clinical outcomes for tracheal stents in adults with benign tracheal disease.

METHODS

A comprehensive literature search in April 2021 identified 556 articles related to tracheal stents. One-hundred and twenty-eight full-text articles were reviewed and 58 were included in the final analysis. Datapoints examined were stent materials, clinical applications and outcomes, and preclinical findings, including emerging technologies.

RESULTS

In the 58 included studies, stent materials were metals (n = 28), polymers (n = 19), coated stents (n = 19), and drug-eluting (n = 5). Metals included nitinol, steel, magnesium alloys, and elgiloy. Studies utilized 10 different polymers, the most popular included polydioxanone, poly-l-lactic acid, poly(d,l-lactide-co-glycolide), and polycaprolactone. Coated stents employed a metal or polymer framework and were coated with polyurethane, silicone, polytetrafluoroethylene, or polyester, with some polymer coatings designed specifically for drug elution. Drug-eluting stents utilized mitomycin C, arsenic trioxide, paclitaxel, rapamycin, and doxycycline. Of the 58 studies, 18 were human and 40 were animal studies (leporine = 21, canine = 9, swine = 4, rat = 3, ovine/feline/murine = 1). Noted complications included granulation tissue and/or stenosis, stent migration, death, infection, and fragmentation.

CONCLUSION

An increasing diversity of materials and coatings are employed for tracheal stents, growing more pronounced over the past decade. Though most studies are still preclinical, awareness of tracheal stent developments is important in contextualizing novel stent concepts and clinical trials. Laryngoscope, 132:2111-2123, 2022.

Post-tuberculosis tracheobronchial stenosis: long-term follow-up after self-expandable metallic stents placement and development of a prediction score-the Restenosis Score

Background

The insertion of self-expandable metallic stents (SEMS) for post-tuberculosis tracheobronchial stenosis (PTTS) was controversial. This study aimed to evaluate the efficacy and safety of SEMS for treating PTTS, and developed a scoring system for predicting the occurrence of restenosis after stenting in PTTS patients.

Methods

We conducted a retrospective review of 87 patients who were diagnosed with PTTS and experienced SEMS insertion between January 2000 and December 2017. All procedures were performed via flexible bronchoscopy under conscious sedation and local anesthesia.

Results

A total of 85 SEMS were successfully placed in 77 patients. Comparing with pre-stenting, there were significant improvements in the lumen diameters of the stenotic segment, mMRC scale and lung function after short-term SEMS placement. During the long-term (average 163.32 months) follow-up, 48 patients (62.3%) did not develop restenosis after stenting; the other 29 patients (37.7%) developed and eventually, 12 remained under interventional therapies and 11 had bronchial atresia. Multivariate Cox regression analysis revealed that the difference value between SEMS length and the stenosis-segment length, stenosis type, and the number of pre-stenting thermal ablation were independently related to restenosis occurrence and were subsequently used to establish the Restenosis Score. The model’s development group (0.83, 95% CI 0.74–0.92) and external validation set (0.94, 95% CI 0.77–1.00) showed excellent discrimination.

Conclusion

SEMS placement could serve as a safe and effective treatment option for most patients with PTTS. Further, we built a prediction model depending on the independent predictors of restenosis occurrence, the Restenosis Score. This validated tool might provide a decision support and a better management for PTTS patients who underwent SEMS implantation.

A narrative review of new research progress regarding the use of airway stents in benign airway stenosis

INTRODUCTION

Benign airway stenosis is a severe disease that can result in death with improper treatment. Clinicians must know about airway stents to choose the best one in their daily practice.

AREAS COVERED

PubMed, Embase, and other electronic databases and websites were searched to identify relevant randomized controlled trials and meta-analyses. This review summarizes different types of airway stents and analyzes their advantages and disadvantages.

EXPERT OPINION

Increasing attention has been given to the indications and prognosis of benign airway stenosis treated with different airway stents. With more investigations and data, better alternatives to silicone stents could be developed in the future.

A 12-year experience in endobronchial intervention using rigid bronchoscopy - account of a tertiary referral centre

We describe our experience of rigid bronchoscopy and endobronchial intervention at a single tertiary centre over a 12-year period. All rigid bronchoscopy procedures between July 2008 and July 2020 (inclusive) were reviewed. All procedures were performed in cardiothoracic theatres by a designated team under general anaesthesia. 2135 rigid bronchoscopies were performed on 1301 patients aged between 18 and 93 years. Complications occurred in 24 (1.12%) procedures. There was one fatality (0.05%). Haemorrhage >100mls occurred in seven (0.33%) all of which were successfully managed endobronchially. Ten procedures (0.5%) were complicated by pneumothorax and an intercostal drain was required for eight. Five patients required intensive care admission post operatively, all of whom were subsequently discharged from hospital. One patient had stent migration. To the best of our knowledge, this is amongst the largest single centre collection of data available for endobronchial intervention using rigid bronchoscopy. We show that rigid bronchoscopy is a safe and effective procedure when performed in a high-volume specialist centre with designated lists involving a specialist multidisciplinary team.

Surgery Complicated by Self-Expandable Metallic Stents (SEMS) Tracheal Stent in a Congenital H-type Tracheo-Esophageal Fistula

A congenital tracheo-esophageal fistula of the H-type is a rare variant. The diagnosis is usually missed because of mild symptoms. A long history of coughing during liquid intake and nocturnal cough may aid in the diagnosis. A delay in the diagnosis may have a deleterious effect on the lung because of recurrent infections. Surgery is the cornerstone of management. Self-expandable metallic stents (SEMS) do not have a role in the management of these fistulae. We report a case of a missed diagnosis of a congenital H-type fistula managed as an acquired tracheo-esophageal fistula with two attempts at conservative management with a tracheal self-expandable metallic stent. The difficulties and disadvantages of using self-expandable metallic stents for the management of benign tracheo-esophageal fistulae are also discussed.

Placing covered self-expanding metal stents by suspension laryngoscope in benign tracheal stenosis

BACKGROUND

Tracheobronchial stent placement for malignant airway strictures has been proved to improve respiratory function, but experience for benign tracheobronchial stenoses is limited. The purpose of our study is to investigate the efficacy of covered expandable metallic stents, inserted through a suspension laryngoscope, treating tracheal stenosis following intubation or tracheostomy.

METHODS

From 2010 to 2018, 67 adult patients with the benign tracheal stenosis, underwent stent placement, using a suspension laryngoscope. According to the date of stent placement and stent caliber, these patients have been subdivided into two groups: Group 1 (from 2010 to 2013, stent caliber ranging from 16 to 20 mm) and Group 2 (from 2014 to 2018, stent caliber ranging from 18 to 22 mm). Complications, related reinterventions, and long-term prognosis were retrospectively evaluated.

RESULTS

Primary successful stent placement was achieved and symptoms were improved in all patients. Complications occurred in 27 (40.3%) cases. Among these, there were 14 (20.9%) cases with stent migration, 10 (14.93%) with granulation tissue formation and 3 (4.48%) with pneumonia. Stent migration in Group 1 was nearly 30% higher than that in Group 2 (P = 0.002). Five of the 8 patients who had placement of 16 mm stents had stent migration, more often than with 20 mm stents (P = 0.002). Ten patients' trachea had slight narrowing but without any symptoms. Six patients still had granulation tissue but without any growth at least two-year follow-up (2 patients whose stents were removed more than 1 year after placement). Even without tracheal narrowing and granulation tissue, 5 patients felt persistent shortness of breath. 92.5% of the patients reported to be satisfied with significant improvement in symptoms.

CONCLUSIONS

Patients with tracheal obstruction secondary to intubation or tracheostomy can benefit from tracheal stents. Placing 16 mm stents might lead to stent migration more easily than 20 mm stents. Tracheal stents placed by a suspension laryngoscope provide a reasonable alternative to open surgery for patients with benign tracheal stenosis or obstruction.

Risk-score model to predict prognosis of malignant airway obstruction after interventional bronchoscopy

Background

Interventional bronchoscopy exhibits substantial effects for patients with malignant airway obstruction (MAO), while little information is available regarding the potential prognostic factors for these patients.

Methods

Between October 31, 2016, and July 31, 2019, a total of 150 patients undergoing interventional bronchoscopy and histologically-confirmed MAO were collected, in which 112 eligible participants formed the cohort for survival study. External validation cohort from another independent institution comprised 33 MAO patients with therapeutic bronchoscopy. The least absolute shrinkage and selection operator regression (LASSO) was applied to the model development dataset for selecting features correlated with MAO survival for inclusion in the Cox regression from which we elaborated the risk score system. A nomogram algorithm was also utilized.

Results

In our study, we observed a significant decline of stenosis rate after interventional bronchoscopy from 71.7%±2.1% to 36.6%±2.7% (P<0.001) and interventional bronchoscopy dilated airway effectively. Patients in our study undergoing interventional bronchoscopy had a median survival time of 614.000 days (95% CI: 269.876–958.124). Patients receiving distinct therapeutic methods of interventional bronchoscopy had different prognosis (P=0.022), and patients receiving treatment of electrocoagulation in combination with stenting and electrosurgical snare had worse survival than those receiving other options. Multivariate Cox analysis revealed that nonsmoking status, adenoid cystic carcinoma, and low preoperative stenosis length, as independent predictive factors for better overall survival (OS) of MAO patients. Then, the nomogram based on Cox regression and risk score system based on results from LASSO regression were elaborated respectively. Importantly, this risk score system was proved to have better performance than the nomogram and other single biomarkers such as traditional staging system (area under the curve 0.855 vs. 0.392–0.739). Survival curves showed that patients with the higher risk-score had poorer prognosis than those with lower risk-score (third quantile of OS: 126.000 days, 95% CI: 73.588–178.412 vs. 532.000 days, 95% CI: 0.000–1,110.372; P<0.001).

Conclusions

Nonsmoking status, adenoid cystic carcinoma, and low preoperative stenosis length, were independent predictive factors for better OS of MAO patients. We proposed a nomogram and risk score system for survival prediction of MAO patients undergoing interventional bronchoscopy with good performance.

Long-term outcomes of metallic endobronchial stents in lung transplant recipients are not affected by bacterial colonization

OBJECTIVES

We evaluated associations of endobronchial stenting with airway bacterial colonization, the antimicrobial resistance profile, hospitalizations for pneumonia and survival in lung transplant recipients.

METHODS

This is a retrospective single-centre study of 582 recipients of lung transplant during 2002-2018. We compared outcomes of 57 patients (9.7%) who received endobronchial stents (intervention group) to a control group of 57 patients without stents who were matched one to one for age, sex, year of transplantation, unilateral/bilateral transplantation and underlying disease.

RESULTS

For the intervention compared to the control group, airway colonization was more common for Pseudomonas (86% vs 35%, P < 0.001), Acinetobacter (21% vs 7%, P = 0.05), Klebsiella (21% vs 5%, P = 0.02) and Staphylococcus species (11% vs 0%, P = 0.02). The respective proportions of patients with positive bronchoalveolar lavage cultures on the third post-transplantation day, the day of stent insertion and 6-month post-stent insertion were 47.4%, 50.9% and 65.4% for Pseudomonas sp.; 15.8%, 12.3% and 3.8% for Klebsiella sp.; and 8.8%, 5.3% and 5.8% for Acinetobacter sp. The mean number of hospitalizations for pneumonia per patient was higher, without statistical significance, in the intervention than the control group (1.5 ± 1.7 vs 0.9 ± 1.5, P = 0.1). Kaplan-Meier survival curves did not show a statistically significant difference between the intervention group and the entire group without endobronchial stents (n = 525) (P = 0.4).

CONCLUSIONS

Lung transplant recipients with endobronchial stents were more likely to be colonized with pathologic bacteria and having pneumonia; however, stent placement was not associated with increased long-term mortality with appropriate stent maintenance.

Application of Montgomery T-Tube Placement in Treating Cotton-Myer IV Subglottic Airway Atresia after Bi-Level Airway Recanalization

Objective

The purpose of this study is to explore the effectiveness and safety of Montgomery T-tube placement in treating Cotton-Myer IV subglottic airway atresia after bi-level airway recanalization.

Methods

This study is a retrospective study. 11 patients who were treated for IV subglottic airway atresia between January 2017 and January 2019 in the Second Affiliated Hospital of Jiaxing University were involved in this study. The 11 patients all had undergone tracheotomies at our hospital, and they were transferred to the Department of Pulmonary and Critical Care Medicine for Montgomery T-tube placement after bi-level airway recanalization when their subglottic airway was atretic. Patients were observed for their clinical manifestations after placement. The effectiveness of T-tube placement after bi-level airway recanalization was assessed. The incidence of short-term and long-term complications after surgery was assessed. Patients were followed up for 3 to 24 months for evaluating their airway recovery.

Results

T-tubes were successfully placed in 11 patients. The atretic airways of all patients were recanalized after treatment. Eight patients got restoration of vocal ability, and 3 patients could only say simple words. None of the patients needed assisted oxygen inhalation. The SpO2 average level was increased from 95 ± 2% before treatment to 97 ± 3% after treatment. Patients had significant relief of cough or sputum, and they had less difficulty in dyspnea. All short- or long-term complications were self-relieved or controlled without further malignant progression after treatment by doctors. The average postoperative extubating time was (14.86 ± 3.62) months.

Conclusion

The application of Montgomery T-tube placement in treating Cotton-Myer IV subglottic airway atresia after bi-level airway recanalization is well effective and safe for patients, and it can be promoted in clinical treatment.

A flexible porous chiral auxetic tracheal stent with ciliated epithelium

Tracheal stent placement is a principal treatment for tracheobronchial stenosis, but complications such as mucus plugging, secondary stenosis, migration, and strong foreign body sensation remain unavoidable challenges. In this study, we designed a flexible porous chiral tracheal stent intended to reduce or overcome these complications. The stent was innovatively designed with a flexible tetrachiral and anti-tetrachiral hybrid structure as the frame and hollows filled with porous silicone sponge. Detailed finite element analysis (FEA) showed that the designed frame can maintain a Poisson's ratio that is negative or close to zero at up to 50% tensile strain. This contributes to improved airway ventilation and better resistance to migration during physiological activities such as respiration and neck movement. The preparation process combined indirect 3D printing with gas foaming and particulate leaching methods to efficiently fabricate the stent. The stent was then subjected to uniaxial tension and local radial compression tests, which indicated that it not only has the same desirable auxetic performance but also has flexibility similar to the native trachea. The porous sponge facilitated the adhesion of cells, allowed nutrient diffusion, and would prevent the ingrowth of granulation tissue. Furthermore, a ciliated tracheal epithelium similar to that of the native trachea was differentiated from normal human bronchial primary epithelial cells on the internal wall of the stent under air-liquid interface conditions. These results suggest that the designed stent has the potential for application in the treatment of tracheobronchial stenosis.

Clinical outcomes and survival following placement of self-expandable metallic stents for central airway stenosis and fistula

Background

Self‐expandable metallic stent (SEMS) placement is an urgent procedure for patients with malignant central airway stenoses (CASs) and central airway fistulas (CAFs). The aim of this study was to determine the outcome and survival after SEMS placement in patients with malignant CASs and CAFs.

Methods

SEMSs were inserted into 20 patients with malignant CASs and four with malignant CAFs. Hospital records, the modified Medical Research Council dyspnea scale (mMRC) grade, performance status (PS), symptoms, procedure‐related complications and survival after placement were retrospectively reviewed.

Results

Spiral Z stents were inserted in nine patients, covered Ultraflex stents in 14, and a bare Ultraflex in one patient. After SEMS placement, 20 patients (83.3%) showed improvement in mMRC grade, 19 (79.2%) showed improvement in PS, and 21 (87.5%) showed improvement in symptoms. There were three patients whose stents migrated out of place, but there were no patients with obstructive granulation, infection, or mucous plugs. Median survival days after stent insertion was 98 days for CAS and 103 days for CAF, and mean survival days was 383 ± 707 days for CAS and 93 ± 33 days for CAF. Two patients with CAS by malignant lymphoma and thymic cancer survived more than six years because they were also treated with efficient therapies. The five‐year survival rate after stent insertion was 7.7%.

Conclusions

SEMS placement for CAS and CAF is associated with improvement in mMRC grade, PS and symptoms in 87.5% of patients. Patients with a malignant CAS are usually terminal, but the possibility of increasing survival rate will become a reality with new efficient therapies.

Key points

Significant findings of the study

Reasonable clinical outcomes and improved survival of patients following SEMS placement for thoracic malignancy with central airway stenosis and fistula.

What this study adds

The possibility of increasing survival rate will become a reality with new efficient therapies.

Clinical Outcomes of Complications Following Self-Expandable Metallic Stent Insertion for Benign Tracheobronchial Stenosis

Background and Objectives: The use of metallic stents in benign TBS is controversial. Here, we report the clinical outcomes of patients who developed complications due to self-expandable metallic stent (SEMS) insertion for benign TBS. Materials and Methods: Our institution, which is the largest and most active referral hospital for airway stenosis in South Korea, only uses silicone stents. We conducted a retrospective review of 20 patients referred after the insertion of SEMS for benign TBS from 2006 to 2015. Results: All 20 patients underwent rigid bronchoscopy for SEMS removal due to airway obstruction from granulation tissue overgrowth. All but one (95%) experienced successful removal of the SEMS. During a median follow-up period of 40 months, a median of seven rigid bronchoscopies per patient was needed to maintain airway patency. Three (15%) patients suffered acute complications during SEMS removal (bleeding (10%) and fistula (5%)). All patients suffered chronic complications (granulation tissue (80%), stent migration (58%), mucostasis (55%), and restenosis (43%)). Eventually, 15 patients (75%) needed airway prostheses (silicone stent (75%) and tracheostomy (25%)). Conclusion: Our findings indicate that SEMS should be avoided until positive results are consistently reported by high-quality studies in patients with benign TBS.

Long-term outcomes of tracheobronchial stenosis due to tuberculosis (TSTB) in symptomatic patients: airway intervention vs. conservative management

Background

Patients with tracheobronchial stenosis due to tuberculosis (TSTB) have a variable clinical course and response to treatment including airway intervention. There are no clear guidelines on the best approach to manage such patients. This study examines long-term outcomes of patients with TSTB and factors associated with recurrent symptoms or need for repeat airway intervention following initial bronchoscopic intervention.

Methods

This is a retrospective analysis of patients with TSTB over an 18-year period. Symptoms, radiological, bronchoscopic findings, airway interventions and complications were obtained. Multivariate logistic regression analysis was performed to identify factors predictive of recurrence of symptoms or need for repeat airway intervention.

Results

A total of 131 patients with mean age 50±18 years and median follow-up 5 (interquartile range, 2–10) years were included. Nineteen (29.7%) patients underwent balloon dilatation alone, 22 (34.4%) had additional resection or stenting, and 19 (29.7%) underwent all 3 procedures. Among patients conservatively managed, a larger proportion (55.6%) of patients with no recurrence of symptoms had active TB. Patients who developed recurrent symptoms had longer symptom duration (12 vs. 3 months, P=0.025), and more had recurrent lower respiratory tract infections (50% vs. 5.6%, P=0.003), lung collapse (90.0% vs. 41.7%, P=0.011) or linear fibrosis (70.0% vs. 30.6%, P=0.033) compared to those without recurrent symptoms. Bronchomalacia (OR =17.18; 95% CI, 3.43–86.18) and prior bronchoscopic airway resection (OR =4.97; 95% CI, 1.20–20.60) were strongly associated with the recurrence of symptoms or need for repeat airway intervention on multivariate logistic regression analysis.

Conclusions

Bronchomalacia and prior bronchoscopic airway resection are associated with the recurrence of symptoms despite airway intervention. Patients who are diagnosed with TSTB early in the course of active TB may be conservatively managed.

Reactivity Study of a Biodegradable Polydioxanone Tracheal Stent in a Rabbit Model

INTRODUCTION

The objective of this study was to evaluate tracheal reactivity induced by a biodegradable polydioxanone tracheal stent.

MATERIALS AND METHODS

Twenty-two rabbits were divided into 3 groups assigned to different survival times (30, 60 and 90days post-implantation). A biodegradable stent was implanted in each animal, except for 1 of each group (negative control). Implantation was performed through a small tracheotomy under fluoroscopic control. CT and histopathological studies were scheduled at the end of survival times.

RESULTS

No animal died during the procedure or follow-up. The stent had disappeared in 100% of the cases at 90days, in 50% at 60days, and in none at 30days. CT studies revealed a greater tracheal wall thickness at 30days than at 60 and 90days (1.60±0.41mm in the central part of the stent versus 1.11±0.18 and 0.94±0.11; P=.007, respectively). No granulomas were observed on histopathology. Some degree of histological changes were noted at 30days, which had reduced at 60 and 90days. Differences were also found in both CT and histology between animals in which the stent was present and animals in which it had degraded.

CONCLUSIONS

Polydioxanone stents produce a mild reaction that reverts with tracheal degradation. The use of these biodegradable stents in benign tracheal disease is promising.

Long-term tumour outcomes of self-expanding metal stents as 'bridge to surgery' for the treatment of colorectal cancer with malignant obstruction: a systematic review and meta-analysis

PURPOSE

To explore the long-term oncological results of self-expanding metal stents (SEMS) as a surgical transition compared with those of simple emergency surgery.

METHODS

A systematic review of studies involving long-term tumour outcomes comparing SEMS with emergency surgery was conducted. All studies included information on 3-year and 5-year survival rates, 3-year and 5-year disease-free survival (DFS) rates, and local and overall recurrence rates; the results were expressed as odds ratios.

RESULTS

Overall, 24 articles and 2508 patients were included, including 5 randomised controlled trials, 3 prospective studies, and 16 retrospective studies. The 3-year survival rate (odds ratio (OR) = 0.88, 95% confidence interval (CI) 0.69-1.12, P = 0.05), 5-year survival rate (OR = 0.91, 95% CI 0.70-1.17, P = 0.67), 3-year DFS rate (OR = 1.14, 95% CI 0.91-1.42, P = 0.65), 5-year DFS rate (OR = 1.35, 95% CI 0.91-2.02, P = 0.17), overall recurrence rate (OR 1.04, 95% CI 0.77-1.41, P = 0.14), and local recurrence rate (OR 1.37, 95% CI 0.84-2.23, P = 0.92) were determined. There was no significant difference between the randomised and observational studies in the subgroup analysis, and the 5-year survival rate was higher in studies with a stent placement success rate of ≥ 95%.

CONCLUSION

SEMS implantation was a viable alternative in malignant left colon obstruction as a transition to surgery; its long-term survival results, including 5-year DFS and overall survival, were equivalent to those of emergent surgery.

Long-term tolerance of a fractured self-expanding metal stent in a patient with adenoid cystic carcinoma

Self-expanding metals stent are used for recanalization of malignant CAO. Fracture of such a stent has been described. This prompts its removal. However removal of a metal stent is difficult and can be hazardous. Due to this US FDA advisory was released against their insertion in benign diseases where long life expectancy can expose the patients to the complications of prolonged indwelling time of these stents. We describe a case of adenoid cystic carcinoma who required SEMS placement for tracheal obstruction. However, stent fracture developed soon after its insertion causing patient to cough out stent pieces multiple times. In view of the challenge associated with removal of metal stent fixed to the tracheal walls at its proximal and distal ends, the stent was left in-situ. Patient has tolerated the fractured stent for 1-year and remains on follow-up without any complication or adverse event. This illustrates the long-term tolerance and safety of a fractured stent and helps to allay anxiety associated with this complication.