Airway Stents Research Articles

An Ovine Model Yields Histology and Gene Expression Changes Consistent with Laryngotracheal Stenosis.

Animal models for laryngotracheal stenosis (LTS) are critical to understand underlying mechanisms and study new therapies. Current animal models for LTS are limited by small airway sizes compared to human. The objective of this study was to develop and validate a novel, large animal ovine model for LTS. Sheep underwent either bleomycin-coated polypropylene brush injury to the subglottis (n = 6) or airway stent placement (n = 2) via suspension microlaryngoscopy. Laryngotracheal complexes were harvested 4 weeks following injury or stent placement. For the airway injury group, biopsies (n = 3 at each site) were collected of tracheal scar and distal normal regions, and analyzed for fibrotic gene expression. Lamina propria (LP) thickness was compared between injured and normal areas of trachea. No mortality occurred in sheep undergoing airway injury or stent placement. There was no migration of tracheal stents. After protocol optimization, LP thickness was significantly increased in injured trachea (Sheep #3: 529.0 vs. 850.8 um; Sheep #4: 933.0 vs. 1693.2 um; Sheep #5: 743.7 vs. 1378.4 um; Sheep #6: 305.7 vs. 2257.6 um). A significant 62-fold, 20-fold, 16-fold, 16-fold, and 9-fold change of COL1, COL3, COL5, FN1, and TGFB1 was observed in injured scar specimen relative to unaffected airway, respectively. An ovine LTS model produces histologic and transcriptional changes consistent with fibrosis seen in human LTS. Airway stent placement in this model is safe and feasible. This large airway model is a reliable and reproducible method to assess the efficacy of novel LTS therapies prior to clinical translation. N/A Laryngoscope, 134:4239-4245, 2024.

Further experience with polydioxanone airway stents in children.

The aims of this study were to update our experience with biodegradable polydioxanone (PDO) airway stents in children, focusing on effectiveness and safety, and to analyze the factors involved in the different outcomes observed. Retrospective study of patients managed with PDO stents from 2012 to 2023. Variables collected: demographics, comorbidities, indication, clinical baseline, stent size, location, complications, clinical outcome, and time of follow-up. Statistical analyses were performed to detect the eventual contribution of variables in the different outcomes observed. Fifty-four PDO stents were placed in 26 patients (median age, 4 months). All showed severe symptoms of central airway obstruction due to tracheomalacia in nine patients, bronchomalacia five, tracheobronchomalacia 10, and tracheal stenosis two. Stent placement was uneventful in every case: 29 stents in the trachea and 25 in the main bronchi. 53.8% of patients needed successive stenting, and all exhibited comorbidities. Complete clinical resolution was observed in eight cases (30.7%), partial improvement in 13 (50%), unchanged in 4 (15.3%), and worsened in one. Age had a significant positive impact on outcome (6 vs. 3 months; p = 0.024). Additionally, smaller stents were associated with a better outcome (20 vs. 26 mm; p = 0.044). Granulation tissue was the most frequent complication (34.6%). Five patients (19.2%) died due to severe comorbidities, follow-up was complete in survivors (median, 58 months). PDO stents are safe and effective when dealing with severe tracheobronchial obstruction. Stent-related granulation tissue continues to be a relevant matter of concern. This issue, together with increased degradation times, deserves further research.

Short-course Radiotherapy for Airway Stenting in Malignant Airway Obstruction: A Case Report and Literature Review.

Malignant airway obstruction (MAO) secondary to tumor growth occurs in nearly a third of patients with lung cancer and portends a very poor prognosis if untreated. Treatment options include bronchoscopic intervention with tumor debulking, stent placement, endobronchial brachytherapy, or palliative radiotherapy. This is a report of a 74-year-old woman with a medical history of metastatic lung adenocarcinoma, hospitalized for dyspnea, hemoptysis, and chest pain with a radiographic finding of MAO on chest X-ray and computed tomography. Patient underwent radiation with a total dose of 13 Gy in two once-weekly fractions of 6.5 Gy per fraction. Three days after the end of radiation treatment, chest X-ray showed a completely right lung re-expansion without atelectasis. Two weeks after radiotherapy treatment, the patient was discharged from hospital without pulmonary symptoms. A different fractionation with a lower equivalent dose in 2 Gy fraction compared to literature data showed efficacy in resolving MAO with excellent local control in the first three months of follow-up.

Therapeutic bronchoscopy for malignant central airway obstructions caused by non-bronchogenic cancers: Results from the EpiGETIF registry.

Little is known about malignant central airway obstruction (MCAO) complicating the metastatic spread of non-bronchogenic solid cancers (NBC) and their bronchoscopic management. This study aimed to describe the epidemiology of this population and determine prognostic factors before therapeutic bronchoscopy (TB). In this multicenter study using the EpiGETIF registry, we analysed patients treated with TB for MCAO caused by NBC between January 2019 and December 2022. From a database of 2389 patients, 436 patients (18%) with MCAO and NBC were identified. After excluding patients with direct local invasion, 214 patients (8.9%) were analysed. The main primaries involved were kidney (17.8%), colon (16.4%), sarcoma (15.4%), thyroid (8.9%) and head and neck (7.9%) cancers. Most patients (63.8%) had already received one or more lines of systemic treatment. Obstructions were purely intrinsic in 58.2%, extrinsic in 11.1% and mixed in 30.8%. Mechanical debulking was used in 73.4% of cases, combined with thermal techniques in 25.6% of cases. Airway stenting was required in 38.4% of patients. Median survival after TB was 11.2 months, influenced by histology (p = 0.002), performance status (p = 0.019), initial hypoxia (HR 1.45 [1.01-2.18]), prior oncologic treatment received (HR 1.82 [1.28-2.56], p < 0.001) and assessment of success at the end of the procedure (HR 0.66 [0.44-0.99], p < 0.001). Complications rate was 8.8%, mostly mild, with no procedure-related mortality. TB for MCAO caused by a NBC metastasis provides rapid improvement of symptoms and prolonged survival. Patients should be promptly referred by medical oncologists for bronchoscopic management based on the prognostic factors identified.

The "Hitch-Stitch" for Preventing High Tracheal Stent Migration: Expanding Indications and Extended Experience.

Airway stenting is a standard treatment option for tracheo-bronchial obstruction and other conditions like tracheo-esophageal fistula (TEF). To prevent stent migration, a percutaneous fixation strategy called the "hitch-stitch" was described in 2016 as an efficient technique. We describe an extended experience of the "hitch-stitch" for silicone stents in high tracheal stenting situations and expanding indications to metal stents. Seventy-four percutaneous stitches were placed in 54 patients (36 males and 18 females). The mean age of the patients was 42 (±19) years. The indication for stenting was tracheal stenosis in 63/74 (85%) cases and TEF in 11/74 (15%) cases. Silicone stents were used in 56/74 (75.5%) cases while self-expanding metal stents (SEMS) were used in 18/74 (24.5%) cases. The majority of the stents (62/74, 85%) were high tracheal stents. The "hitch-stitch" as an anti-migration strategy had a high success rate, with distal stent migration in only 2 cases (2.7%) as the stitch had given way-these were repositioned and hitched with double stitches. Minor complications included delayed skin healing (2.8%) and suture site infection (1.4%), which was successfully managed with oral antibiotics. Stitch removal was easy with no complications. In this large series of percutaneous "hitch-stitch" as a stent migration prevention strategy, long-term data shows it is safe and effective in an expanded cohort of silicone stents. Its extended utility is the successful application to metal stents, especially in TEF, where the consequences can be deleterious. It is simple to do, with minimal extra requirements and not associated with any significant complications.

Preoperative Workup of Patients With Excessive Central Airway Collapse: Does Stent Evaluation Serve a Role?

Tracheobronchoplasty (TBP) is a definitive anatomic intervention for patients with severe symptomatic expiratory central airway collapse. Although stent evaluations have been described for surgical workup, current literature does not address if improvement during stent evaluation is sustained after TBP. We compared health-related quality of life (HRQOL) and functional status responses after airway stenting to those post-TBP. A retrospective review was performed in patients with severe expiratory central airway collapse who underwent stent evaluation followed by TBP from January 2004 to December 2019. Baseline, poststent, 3- and 12-month postoperative HRQOL scores, and functional status were analyzed with statistical tests as appropriate. One hundred twenty patients underwent a stent evaluation and TBP. Baseline and stent evaluation measurements were compared with statistically and clinically significant differences in the Cough Quality-of-life Questionnaire (CQLQ) (55 vs. 68, P <0.01), Modified Medical Research Council (mMRC) 0 to 2 (90% vs. 47%, P <0.01), 6-minute walk test (6MWT) (1301ft vs. 1138ft, P <0.01). Improvements in the HRQOL and functional status were maintained from stent evaluation to 3 months postoperatively [CQLQ 55 vs. 54, P =0.63; mMRC 0 to 2 (87% vs. 84%), P =0.39; 6MWT 1350ft vs. 1314ft, P =0.33], and 12 months postoperatively [CQLQ 54 vs. 54, P =0.91; mMRC 0 to 2 (95% vs. 86%), P =0.74; 6MWT 1409ft vs. 1328ft, P =0.13]. The magnitude of change between the data was not significantly different between the stent evaluation, 3-, and 12 months postoperative. Predicted forced expiratory volume in 1-second measurements at baseline, after stent placement, 3 months, and 12 months post-TBP were 74%, 79%, 73%, and 73%, respectively, and not clinically significant. Improvement after stent evaluation and the magnitude of improvement may be predictive of postoperative outcomes up to 1 year after surgery.

Airway stenting for liberation from positive pressure ventilation in patients with central airway obstruction presenting with acute respiratory failure

BackgroundCentral airway obstruction (CAO) can lead to acute respiratory failure (RF) necessitating positive pressure ventilation (PPV). The efficacy of airway stenting to aid liberation from PPV in patients with severe acute RF has been scarcely published. We present a systematic review and our recent experience. MethodsA systematic review of PubMed was performed, and a retrospective review of cases performed at our two institutions from 2018 to 2022 in adult patients who needed stent insertion for extrinsic or mixed CAO complicated by RF necessitating PPV. ResultsFifteen studies were identified with a total of 156 patients. The weighted mean of successful liberation from PPV post-stenting was 84.5% and the median survival was 127.9 days. Our retrospective series included a total of 24 patients. The most common etiology was malignant CAO (83%). The types of PPV used included high-flow nasal cannula (HFNC) (21%), non-invasive ventilation (NIV) (17%) and Invasive Mechanical Ventilation (62%). The overall rate of successful liberation from PPV was 79%, with 55% of HFNC and NIV cases being liberated immediately post-procedure. The median survival of the patients with MCAO that were successfully liberated from PPV was 74 days (n = 16, range 3–893 days), and for those with that failed to be liberated from PPV, it was 22 days (n = 4, range 9–26 days). ConclusionIn patients presenting with acute RF from extrinsic or mixed morphology CAO requiring PPV, airway stenting can successfully liberate most from the PPV. This may allow patients to receive pathology-directed treatment and better end-of-life care.

Study on the rationality of small diameter metallic airway stent in treatment of tracheal stenosis in injured rabbits

BackgroundTo observe the occurrence of related complications after self-expandable metallic (SEM) airway stents implantation with different diameters at different time points, and to provide theoretical basis for the optimal chioce of existing airway stents in clinical practice.MethodsHealthy New Zealand white rabbits were used to establish benign tracheal stenosis models after chest CT examination. Forty-fivemodel rabbits with more than 50% of airway stenosis were divided into two groups. Small-diameter SEM stents (The ratio of stent diameter to airway diameter is nearly 1.0) were implanted in Group A in 21 rabbits, and large-diameter tracheal stents (The ratio of stent diameter to airway diameter is more than 1.2) were implanted in Group B in 24 rabbits. Stent-related complications were observed after stent implantation in 2nd,4th,8th, and 12th week by bronchoscopygross anatomy, pathological and the expressions of IL-1RA, IL-8 and MMP9 in involved tracheal.ResultsThe incidence rate of tracheomalacia of stent was significantly higher in group B (24/24 100%) than that in group A (1 /21,4.8%) (P < 0.05). The incidence rate of scar contracture at both ends of stent was significantly higher than in group B (11 / 24,45.8%) that in group A (2 /21, 9.5%) (P < 0.05). The pathological results of both A and B showed that the columnar epithelium of bronchial mucosa began to damage and detach, inflammatory cells infiltrated after 2nd and 4th week of stenting, The epithelium was repaired, the lamina propria glands almost disappeared, collagen fiber proliferation was obvious, and scars were formed after 8th and 12th week of stenting. ELISA results revealed that the expressions of IL-1RA, IL-8, and MMP9 were increased in the stent group than in model rabbit with benign tracheal stenosis. IL-1RA and MMP9 increased at different periods in group B, but the expression of IL-1RA and MMP9 showed a tread of increasing in the early stage and then decreasing in group A.ConclusionMetal stents can cause different degrees of stent-related complications in rabbits with benign tracheal stenosis. The incidence of stent-induced tracheomalacia and scar contracture were higher in Group B than that in Group A. IL-1RA, IL-8 and MMP9 may be involved in the development of complications after stentimplantation and peak value of group B movered backward. ing.

Airway Stents in Interventional Pulmonology

Airway stents, first developed in the 1980s, have become fundamental in managing a multitude of airway pathologies and complications within the field of interventional pulmonology. The primary function of an airway stent is to re-establish airway patency and integrity when obstruction, stenosis, anastomotic dehiscence, or fistulae develop as a result of various malignant or benign conditions. Nevertheless, airway stents are foreign bodies that can result in complications. In this review article, we will discuss airway stents and their ongoing role in the management of several malignant and benign diseases. We will describe indications for airway stenting and review the elements that must be taken into consideration for optimal patient and stent selection. Given the prevalence of data regarding therapeutic bronchoscopy and airway stenting in malignant airway obstruction, much of the discussion in this review will focus on stent placement for that indication. We will also review the data as it pertains to safety, efficacy, and complications after stent placement, and conclude with a discussion of the future applications and research avenues related to airway stents.

Airway stent associated respiratory tract infections

Airway stent associated respiratory tract infections

Pedicled pericardial patch in tracheal reconstruction in children – Novel technique to provide vascularized tissue for salvaging difficult airways

BackgroundManagement of large central airway defects are often complex. Children who present with these defects have multiple co-morbidities or have had previous surgeries. Surgical options include various tissue cover for these defects without longer term benefits. Vascularized autologous pericardial patch offers a better solution to these defects by providing vascularity and potential for remodelling in future. Methods41 children (M:F of 24:17) were operated for large trachea-bronchial defects between January 2015 and August 2022. The median age of was 12 months with median weight of 8.9 kg (IQR 3.3 kg–17.7 kg) Causes leading to the central tracheal defect include failed repair of previous trachea-oesophageal fistula (TOF) (n = 21) and acquired fistula due to button battery injury (n = 11). Surgical repair consisted of autologous pedicled pericardial patch repair for the airway defect under cardiopulmonary bypass. ResultsThere were two operative deaths related to extensive sepsis and necrosis of reconstructed trachea. Four children had further reoperation with additional patch. Bronchoscopy was used as surveillance in all these children, with use of airway stents (biodegradable stent) in 9 children. The median ventilation time was 8 days, with tracheostomy being needed in 5 for long term support. ConclusionsAutologous pericardial patch is a versatile technique and can be used to salvage large tracheal defects when other method have failed or not feasible. Tracheomalacia at the site of repair could be managed with biodegradable stents. Vascularity and ciliary function of the patch still needs to be evaluated.

Efficacy of airway stenting and nasogastric tube insertion in airway-esophageal fistula patients with airways compromised by advanced malignancy.

Whether airway-compromised airway-esophageal fistula (AEF) patients should undergo combined airway and esophageal stenting is controversial. This study was designed to evaluate the survival prognosis and poststent interventions in AEF patients with airways compromised by advanced malignancy with or without airway stents. A retrospective analysis of the medical records, survival times, and poststent interventions of 17 patients with or without airway stents was performed. The causes of AEF were esophageal cancer (11/17, 64.7%), lung cancer (6/17, 29.4%), and thyroid cancer (1/17, 5.9%). All patients received a nasogastric tube (n = 12) or underwent gastrostomy (n = 5) to resume enteral nutrition. Thirteen patients underwent airway stent insertion (13/17, 76.5%), whereas four patients did not. Four patients with a high risk of stent migration received external stent fixation to the trachea. Three of the patients with stents suffered severe granulation tissue formation and needed repeated bronchoscopy interventions. In the stented group, none of the patients developed stent migration, and the overall median survival time was 9months, compared with 1.25 months in the nonstented group (P = 0.04). Cox proportional hazards regression revealed that stent insertion, nasogastric tube insertion, and transcatheter bronchial artery chemoembolization were protective factors against death, whereas surgery-related fistula, fistula larger than 2cm, continued chemotherapy, and age were risk factors for poor survival (P < 0.05). In airway-compromised AEF patients, airway stents and nasogastric tubes are probably the preferred treatments. Airway stenting is tolerable, and routine weekly poststent bronchoscopy is needed in the first month and depending on respiratory symptoms thereafter.

Advances in Airway Stenting

Advances in Airway Stenting

Bilateral stenting for malignant tracheal and bronchial stenosis

Malignant lesions of tracheal bifurcation usually lead to respiratory failure and risk of mortality. Airway stenting is the only minimally invasive method for these patients. The authors present a patient with T4N3M0 left-sided lung cancer (inoperable stage IIIc) complicated by respiratory failure due to tracheal bifurcation obstruction. Bilateral stenting by self-expanding stents with perforated coatings was effective for airway recanalization and provided subsequent chemotherapy.

A multicenter observational study assessing the safety, feasibility, and complications of Bonastent in central airway obstruction.

Self-expandable metallic stents (SEMS) are increasingly used in the management of both malignant and nonmalignant airway stenosis. There are multiple stents available in the market; however, the current literature on the efficacy and safety of newly available 3rd generation SEMS (Bonastent) is extremely limited and only has data from single center studies. To report the efficacy and early (<7 days) and late (⩾7 days) complications in patients with central airway obstruction (CAO) treated with Bonastent placement at two institutions. We performed a retrospective analysis of data of consecutive patients who underwent therapeutic bronchoscopy and Bonastent placement at two tertiary care university hospitals between January 2019 and November 2023. Bonastent deployment was performed in the operating room. Stents were deployed using rigid or flexible bronchoscopy under direct visualization with a flexible bronchoscope and in conjunction with fluoroscopic guidance. We then analyzed the effectiveness, short-term, and long-term complications of Bonastent placement. A total of 107 Bonastents® were placed in 96 patients. The most common etiology of CAO was malignancy, 92.7% (n = 89), followed by excessive dynamic airway collapse (EDAC) and post-intubation tracheal stenosis. Seventy-three patients (76%) had improvement in symptoms or imaging within 7 days of stent placement, including successful liberation from mechanical ventilation in a patient with CAO. Early complications occurred in seven patients (two-airway bleeding, two-mucus plugging that improved with airway clearance, two-stent migrations, and one-cough).Late complications occurred in 23 patients (1-stent migration requiring revision bronchoscopy and replacement of airway stent, 11-mucus plugging, 6-granulation tissue, 2-pneumonia, 1-cough, 1-tumor ingrowth/stent fracture, 1-airway emergency due to excessive granulation tissue obstructing the distal end of the stent and had a failed cricothyroidotomy leading to death). Overall, the early complication rate was 7.3% (7/96) and late complication rate was 23.9% (23/96). Our study is the first multicenter study that found a good safety profile with a low complication rate after tracheobronchial Bonastent placement with improvement in symptoms soon after stent placement.

Effectiveness of AERO Stent Placement for Malignant Airway Disorder in Patients with a Poor Performance Status.

Objective Airway stenting is an established procedure for treating various airway disorders. The AERO stent (Merit Medical Systems, South Jordan, USA) is a fully covered self-expandable metallic stent approved for use in Japan in 2014. However, its effectiveness in treating malignant airway disorders in patients with a poor performance status remains unclear. Therefore, we investigated the safety and efficacy of the AERO stent in patients with malignant airway disorders and a poor performance status. Methods We retrospectively reviewed the medical records of all patients who underwent AERO stent placement at our institute between April 2016 and March 2022, and 21 patients underwent 25 procedures for malignant airway disorders. All AERO stenting procedures were performed using an over-the-wire delivery system with flexible and/or rigid bronchoscopy. Results Eighteen of the 21 patients (85.7%) had a poor general condition (Eastern Cooperative Oncology Group performance status 3 or 4). AERO stents were successfully placed in 23 of the 25 procedures and migrated in the remaining 2 cases. Complications occurred in 10 cases, with infection being the most common (3 cases). Fourteen patients (66.6%) showed an improvement in their performance status. In addition, 5 of the 6 intubated patients were extubated following AERO stenting, and 11 patients subsequently received anticancer treatment. Conclusion The placement of the AERO stent is useful in patients with a poor performance status, including those who are intubated and afflicted with malignant airway disorders.

Anti-cancer, antibacterial airway stent

All-in-one device can repair airflow, prevent infection, and threat the cancer that caused the obstruction.

Our Experience of Placement of Airway Sems in Three Different Scenarios of Lung and Esophageal Malignancy

AbstractMalignant central airway obstruction refers to the obstruction of the trachea, and right or left main bronchus due to neoplastic growth. The airway is generally compromised by ∼50% at presentation when the patient develops symptoms. Diagnosis is done by flexible bronchoscopy and imaging. However, treatment is challenging due to recurrence, and increased vascularity of tumors, owing to dreaded complications of bleeding and airway compromise. Tracheoesophageal fistula is an abnormal communication of the trachea with the esophagus. It occurs in advanced stages of esophageal and lung malignancy. Bronchoscopy and airway stenting is the palliative treatment option due to the advanced stage of the disease. We present three different case scenarios of thoracic malignancies who underwent airway stenting.

How I do it: novel use of a modified nasopharyngeal airway in laryngotracheal stenosis as a temporary stent.

This paper reports the innovative use of a modified nasopharyngeal airway device as a temporary stent in patients with laryngotracheal stenosis. It also discusses the technique of endoscopic stent placement, and our experience in terms of the indications and suitability. The nasopharyngeal airway device was modified to use as an airway stent by trimming it to the desired length. Next, the stent was inserted endoscopically and anchored using a novel approach. The surgery was performed successfully without complications. The patients had full use of their voice while the stent was in situ. No significant granulation tissue was observed. This paper demonstrates the feasibility of using a nasopharyngeal airway device as a temporary stent to prevent restenosis in cases where the patients have a strong demand for phonation. The modified nasopharyngeal airway device is potentially very promising, but cases must be selected carefully to avoid compromising efficacy and safety.

Wirelessly Actuated Ciliary Airway Stent for Excessive Mucus Transportation

AbstractSmall‐scale cilia‐like devices that can manipulate fluids in narrow spaces have great potential in microfluidics, biomechanics, biomedical engineering, and other applications. However, prior studies mostly focus on artificial cilia for pumping fluids in lab‐on‐a‐chip microfluidic applications. The design and control of artificial cilia for transporting viscous mucus in confined and tubular structures remain challenging and medical devices such as airway stents with ciliary function are still missing. Herein, a method is reported that enables integrating artificial cilia arrays on 3D curved surfaces and an airway ciliary stent is presented for excessive mucus transportation. The method allows encoding bioinspired non‐reciprocal motion and metachronal waves for efficient fluid pumping in tubular structures. The method also introduces a lubricant hydrogel coating layer on artificial cilia inspired by the periciliary layer in airway cilia, which further enhances viscous fluid transportation. It is demonstrated that a novel ciliary airway stent can transport viscous porcine mucus in a lung phantom even faster than the respiratory cilia in a healthy human lung. The methods of designing, integrating, and controlling artificial cilia on 3D curved surfaces thus enable the unprecedented function of removing excessive mucus beyond traditional airway stents for treating various lung diseases in a minimally invasive manner.