Airway stabilization with silicone stents for treating adult tracheobronchomalacia: a prospective observational study

Excessive Dynamic Airway Collapse: Large Airway Function During Exercise

Large airway collapse on expiration is an increasingly recognized cause of airway centric symptoms. The 2 primary conditions are tracheobronchomalacia and excessive dynamic airway collapse, the latter a common comorbidity in those with underlying lung disease. The exertional dyspnea associated with these conditions is complex and exercise intolerance is a key clinical feature, despite the fact that the precise relationship is not fully understood. Forced expiratory maneuvers during supine bronchoscopy or imaging studies are used to evaluate these conditions. However, it may be relevant to characterize large airway function during occasions when patients present their symptoms.

The Value of Preoperative Rigid Tracheobronchoscopy for the Diagnosis of Tracheomalacia in Oesophageal Atresia Patients

BACKGROUND

Oesophageal atresia (OA) is often accompanied by tracheomalacia (TM). The aim of this study was to evaluate its presence in OA patients during routine rigid tracheobronchoscopy (TBS) before primary correction and compare this to postoperative TBS and clinical signs of TM.

METHODS

This retrospective cohort study included patients born with OA between June 2013 and December 2022 who had received a TBS before OA correction and had been followed for at least twelve months. Definite TM was postoperatively diagnosed through TBS, and probable TM was defined as having symptoms of TM.

RESULTS

We analysed data from 79 patients, of whom 87% with OA type C. Preoperatively, TM was observed in 33 patients (42% of all patients), seven of whom had severe TM. Definite TM was observed in 21 patients (27%), of whom 15 had severe TM. Forty-one patients (52% of all patients) had developed symptoms of TM within twelve months, including harsh barking cough (n = 15), stridor and/or wheezing (n = 20), recurrent respiratory insufficiency (n = 11), or needing airway surgery (n = 7). The sensitivity of preoperative TBS for the presence of postoperative (definite and probable combined) TM is 50.0%, 95% CI [35.2-64.8], and the specificity 67.6%, 95% CI [51.7-81.1]. Clinical characteristics did not differ between the patients with or without postoperative TM.

CONCLUSIONS

More than half of the studied patients with OA experienced symptoms of TM. While preoperative TBS is routinely performed prior to surgical OA correction, its predictive value for the presence of postoperative TM remains limited.

LEVEL OF EVIDENCE

Level II.

TYPE OF STUDY

Study of Diagnostics Test.

Airway Stents for Excessive Central Airway Collapse: A Randomized Controlled Open-label Trial

BACKGROUND

Short-term airway stent placement (stent evaluation) has been employed to evaluate whether patients with excessive central airway collapse (ECAC) will benefit from tracheobronchoplasty. Although retrospective studies have explored the impact of stent placement on ECAC, prospective randomized controlled trials are absent.

METHODS

This was a randomized open-label trial comparing patients receiving airway stent placement and standard medical treatment (intervention group) versus standard medical treatment alone (control group) for ECAC. At baseline, patients' respiratory symptoms, self-reported measures, and functional capabilities were assessed. Follow-up evaluations occurred 7 to 14 days postintervention, with an option for the control group to crossover to stent placement. Follow-up evaluations were repeated in the crossover patients.

RESULTS

The study enrolled 17 patients in the control group [medical management (MM)] and 14 patients in the intervention group. At follow-up, 15 patients in the MM crossed over to the stent group, resulting in a total of 29 patients in the combined stent group (CSG). Subjectively (shortness of breath and cough), 45% of the CSG exhibited improvement with the intervention compared with just 12% in the MM. The modified St. George Respiratory Questionnaire score in the CSG improved significantly from 61.2 at baseline to 52.5 after stent placement (-8.7, P = 0.04). With intervention, the 6-minute walk test in CSG improved significantly from 364 meters to 398 meters (34 m, P < 0.01). The MM did not show a significant change in the St. George Respiratory Questionnaire score or 6-minute walk test distance.

CONCLUSION

Short-term airway stent placement in patients with ECAC significantly improves respiratory symptoms, quality of life, and exercise capacity.

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

BACKGROUND

Central 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.

METHODS

A 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.

RESULTS

Fifteen 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).

CONCLUSION

In 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.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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) (1301 ft vs. 1138 ft, 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 1350 ft vs. 1314 ft, 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 1409 ft vs. 1328 ft, 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.

CONCLUSIONS

Improvement after stent evaluation and the magnitude of improvement may be predictive of postoperative outcomes up to 1 year after surgery.

Tracheobronchial stents: an expanding prospect

The first dedicated tracheobronchial silicone stent was designed by the French pulmonologist Jean-Paul Dumon. The most common indications for stenting are to minimise extrinsic airway compression from mass effect, maintain airway patency due to intrinsic obstruction or treat significant nonmalignant airway narrowing or fistulae. Silicone stents require rigid bronchoscopy for insertion; however, they are more readily repositioned and removed compared with metallic stents. Metallic stents demonstrate luminal narrowing when loads are applied to their ends, therefore stents should either be reinforced at the ends or exceed the area of stenosis by a minimum of 5 mm. Nitinol, a nickel-titanium metal alloy, is currently the preferred material used for airway stents. Airway stenting provides effective palliation for patients with severe symptomatic obstruction. Drug-eluting and three-dimensional printing of airway stents present promising solutions to the challenges of the physical and anatomical constraints of the tracheobronchial tree. Biodegradable stents could also be a solution for the treatment of nonmalignant airway obstruction.

Management of post-traumatic tracheal stenosis with silicone stent placement

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

Tracheobronchomalacia: an unusual cause of debilitating dyspnoea and its surgical management

Tracheobronchomalacia (TBM) is a progressive weakening of the airways, leading to collapse and dyspnoea. TBM can be misdiagnosed when multiple chronic conditions accompany it. Tracheobronchoplasty (TBP) is indicated for severe symptomatic TBM, diagnosed by bronchoscopy and CT thorax. We report the case of a patient who underwent tracheal resection and reconstruction for continuing dyspnoea post argon therapy, TBP and a failure to tolerate extracorporeal membrane oxygenation-assisted Y-stent insertion. Relevant background history includes asthma, sleep apnoea, reflux, cardiomyopathy and a high body mass index. Bronchoscopy postreconstruction showed patent airways. Airway reconstruction was a viable management option for this patient's TBM. TBP is a treatment option for TBM. In this case, tracheal resection was required to sustain benefit. In addition, surveillance bronchoscopies will be carried out every year.

[Interventionnal bronchoscopy for the treatment of tracheobronchomalacia]

Tracheobronchomalacia is usually characterized by more than 50% expiratory narrowing in diameter of the trachea and the bronchi. The expiratory collapse includes two entities: (1) the TBM related to the weakness of the cartilaginous rings, and (2) the Excessive Dynamic Airway Collapse (EDAC) due to the excessive bulging of the posterior membrane. Patients have nonspecific respiratory symptoms like dyspnea and cough. Diagnosis is confirmed by dynamic tests: flexible bronchoscopy and/or computed tomographic scan of the chest. There are different forms of tracheobronchomalacia in adults: primary (genetic, idiopathic) or secondary to trauma, tracheotomy, intubation, surgery, transplantation, emphysema, infection, inflammation, chronic bronchitis, extrinsic compression; or undiagnosed in childhood vascular rings. Some management algorithms have been proposed, but no specific recommendation was established. Only symptomatic patients should be treated. Medical treatments and noninvasive positive pressure ventilation should be the first line therapy, after evaluation of various quality measures (functional status, performance status, dyspnea and quality of life scores). If symptoms persist, therapeutic bronchoscopy permits: (1) patient's selection by stent trial to determine whether patient benefit for surgical airway stabilization; (2) malacic airways stenting in patients who are not surgical candidates, improving QOL despite a high complication rate; (3) the management of stent-related complication (obstruction, plugging, migration granuloma); (4) alternative therapeutics like thermo-ablative solution. Lasty, the development of new types of stents would reduce the complication rates. These different options remained discussed.

Perioperative considerations for postpneumonectomy syndrome: A case report

Postpneumonectomy syndrome is a rare complication of a pneumonectomy. Patients may experience dyspnea, stridor, recurrent pulmonary infections, or dysphagia due to rotation and shift of the mediastinum. The current intervention of choice involves the placement of a tissue expander in the empty hemithorax to realign the mediastinum. Because this treatment can present with intraoperative anesthetic challenges and requires close monitoring, we present this case to highlight specific concerns that may need to be addressed including difficulties ventilating, complete airway collapse, hemodynamic instability, and pain control perioperatively.

Tracheobronchoplasty: Indications and Best Approaches

Tracheobronchomalacia (TBM) is an increasingly recognized abnormality of the central airways in patients with respiratory symptoms. Severe TBM in symptomatic patients warrants screening dynamic CT of the chest and/or awake dynamic bronchoscopy. The goal of surgical repair is to restore the C-shaped configuration of the airway lumen and splint or secure the lax posterior membrane to the mesh to ameliorate symptoms. Robotic tracheobronchoplasty is safe and associated with improvements in pulmonary function and subjective improvement in quality of life.

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.

Interventional pulmonology techniques in lung transplantation

Lung transplantation is a key therapeutic option for several end-stage lung diseases. Interventional pulmonology techniques, mostly bronchoscopy, play a key role throughout the whole path of lung transplantation, from donor evaluation to diagnosis and management of post-transplant complications. We carried out a non-systematic, narrative literature review aimed at describing the main indications, contraindications, performance characteristics and safety profile of interventional pulmonology techniques in the context of lung transplantation. We highlighted the role of bronchoscopy during donor evaluation and described the debated role of surveillance bronchoscopy (with bronchoalveolar lavage and transbronchial biopsy) to detect early rejection, infections and airways complications. The conventional (transbronchial forceps biopsy) and the new techniques (i.e. cryobiopsy, biopsy molecular assessment, probe-based confocal laser endomicroscopy) can detect and grade rejection. Several endoscopic techniques (e.g. balloon dilations, stent placement, ablative techniques) are employed in the management of airways complications (ischemia and necrosis, dehiscence, stenosis and malacia). First line pleural interventions (i.e. thoracentesis, chest tube insertion, indwelling pleural catheters) may be useful in the context of early and late pleural complications occurring after lung transplantation. High quality studies are advocated to define endoscopic standard protocols and thus help improving long-term prognostic outcomes of lung transplant recipients.

Tracheal Stent Migration in a Patient With Tracheomalacia and Tracheoesophageal Fistula: A Rare Case

Tracheomalacia refers to diffuse or segmental tracheal weakness. Most commonly, tracheomalacia develops after prolonged endotracheal intubation or tracheostomy. Surgical management is warranted in symptomatic patients with severe tracheomalacia. Relief of airway obstruction via stenting often provides immediate improvement in both airflow and symptoms. However, stent placement is associated with significant complications. Here, we present the case of a 71-year-old man who was brought to the emergency department with acute respiratory distress. The patient was known to have tracheomalacia with tracheoesophageal fistula. He had multiple medical comorbidities, including longstanding hypertension, diabetes mellitus, and asthma. The patient had a progressive decline in his level of consciousness and was admitted to the intensive care unit for further management. Despite the maximum ventilatory support, the patient did not achieve an adequate oxygenation level. The patient underwent tracheal stent placement by the interventional radiology team. The insertion was unsuccessful despite three attempts. The tracheal stent had migrated into the upper esophagus on the first and second insertion attempts. Because the patient was unstable to tolerate further attempts, the multidisciplinary team recommended the insertion of an esophageal stent to cover the tracheoesophageal fistula. Despite this, the patient continued to have air leakage with progressive worsening of his respiratory condition as he developed multiorgan failure and died. The management of tracheomalacia in the setting of the tracheoesophageal fistula may pose several challenges. The present case highlights an essential complication of stent placement with the stent migrating into the tracheoesophageal fistula, which is an unusual site of migration. A multidisciplinary approach is crucial in the management of difficult cases of tracheomalacia.

Stent Evaluation for Expiratory Central Airway Collapse: Does the Type of Stent Really Matter?

BACKGROUND

Careful selection of patients with expiratory central airway collapse (ECAC) that may benefit from tracheobronchoplasty (TBP) can be aided by a short-term airway stent evaluation. This can be performed with either silicone Y-stents (SYSs) or uncovered self-expanding metallic airway-stents (USEMAS). No direct comparison has been made between these 2 stent types.

METHODS

This was a small retrospective review of consecutive patients that underwent a stent evaluation. A propensity score was used to match patients in the USEMAS and SYS groups. Outcomes included complications, changes in the health-related quality-of-life (HR-QoL), and changes in exercise capacity. Baseline measurements were compared with those obtained during stent evaluation and after TBP.

RESULTS

Forty-two patients with severe ECAC underwent USEMAS placement, while 18 patients had an SYS placed. Propensity score matching resulted in 13 matched SYS and USEMAS pairs. The SYS group had an increased rate of mucus plugging (38.5% vs. 0%, P <0.047). Although not statically significant, a clinical improvement was observed in HR-QoL and exercise capacity in the USEMAS group during stent placement. In patients who underwent TBP, both USEMAS and SYS groups had a statistically significant change in the Modified Medical Research Council Dyspnea Scale during stent evaluation and after TBP.

CONCLUSION

In patients with severe ECAC, short-term evaluation with airway stents appears to be safe and improves respiratory symptoms, HR-QoL, and exercise capacity. The use of USEMAS led to a lower complication rate, a greater improvement in HR-QoL and exercise capacity, and appeared to better predict how the patients would respond to TBP.

Coordination of Care for Expiratory Central Airway Collapse: A Structured Process for a Multifaceted Disease

Common respiratory symptoms, including dyspnea, cough, sputum production, and recurrent infections, frequently remain without a clear cause and may be the result of expiratory central airway collapse (ECAC). Establishing the diagnosis and appropriate treatment plan for patients with ECAC is challenging and benefits from a multidisciplinary approach. A coordinator role is crucial in this process to ensure optimal patient-centered outcomes. We describe the coordination of care in the process of diagnosing and treating ECAC. The coordinator leads the organization of the multiple services involved in the care of patients with ECAC, including pulmonary medicine, interventional pulmonology, radiology, and thoracic surgery, as well as hospital inpatient staff. From initial screening to evaluation and management with airway stents and corrective treatment with tracheobronchoplasty, the ECAC coordinator oversees the entire process of care for patients with ECAC.

Tracheobronchomalacia and Excessive Dynamic Airway Collapse: Current Concepts and Future Directions

Tracheobronchomalacia (TBM) and excessive dynamic airway collapse (EDAC) are airway abnormalities that share a common feature of expiratory narrowing but are distinct pathophysiologic entities. Both entities are collectively referred to as expiratory central airway collapse (ECAC). The malacia or weakness of cartilage that supports the tracheobronchial tree may occur only in the trachea (ie, tracheomalacia), in both the trachea and bronchi (TBM), or only in the bronchi (bronchomalacia). On the other hand, EDAC refers to excessive anterior bowing of the posterior membrane into the airway lumen with intact cartilage. Clinical diagnosis is often confounded by comorbidities including asthma, chronic obstructive pulmonary disease, obesity, hypoventilation syndrome, and gastroesophageal reflux disease. Additional challenges include the underrecognition of ECAC at imaging; the interchangeable use of the terms TBM and EDAC in the literature, which leads to confusion; and the lack of clear guidelines for diagnosis and treatment. The use of CT is growing for evaluation of the morphology of the airway, tracheobronchial collapsibility, and extrinsic disease processes that can narrow the trachea. MRI is an alternative tool, although it is not as widely available and is not used as frequently for this indication as is CT. Together, these tools not only enable diagnosis, but also provide a road map to clinicians and surgeons for planning treatment. In addition, CT datasets can be used for 3D printing of personalized medical devices such as stents and splints. An invited commentary by Brixey is available online. Online supplemental material is available for this article. ^©RSNA, 2022.

A two-stage in vivo approach for implanting a 3D printed tissue-engineered tracheal replacement graft: A proof of concept

OBJECTIVES

To optimize a 3D printed tissue-engineered tracheal construct using a combined in vitro and a two-stage in vivo technique.

METHODS

A 3D-CAD (Computer-aided Design) template was created; rabbit chondrocytes were harvested and cultured. A Makerbot Replicator™ 2x was used to print a polycaprolactone (PCL) scaffold which was then combined with a bio-ink and the previously harvested chondrocytes. In vitro: Cell viability was performed by live/dead assay using Calcein A/Ethidium. Gene expression was performed using quantitative real-time PCR for the following genes: Collagen Type I and type II, Sox-9, and Aggrecan. In vivo: Surgical implantation occurred in two stages: 1) Index procedure: construct was implanted within a pocket in the strap muscles for 21 days and, 2) Final surgery: construct with vascularized pedicle was rotated into a segmental tracheal defect for 3 or 6 weeks. Following euthanasia, the construct and native trachea were explanted and evaluated.

RESULTS

In vitro: After 14 days in culture the constructs showed >80% viable cells. Collagen type II and sox-9 were overexpressed in the construct from day 2 and by day 14 all genes were overexpressed when compared to chondrocytes in monolayer.

IN VIVO

By day 21 (immediately before the rotation), cartilage formation could be seen surrounding all the constructs. Mature cartilage was observed in the grafts after 6 or 9 weeks in vivo.

CONCLUSION

This two-stage approach for implanting a 3D printed tissue-engineered tracheal replacement construct has been optimized to yield a high-quality, printable segment with cellular growth and viability both in vitro and in vivo.

Central airway obstruction: is it time to move forward?

INTRODUCTION

Central airway obstruction (CAO) represents a pathological condition that can lead to airflow limitation of the trachea, main stem bronchi, bronchus intermedius or lobar bronchus.

MAIN BODY

It is a common clinical situation consensually considered under-diagnosed. Management of patients with CAO can be difficult and deciding on the best treatment approach represents a medical challenge. This work intends to review CAO classifications, causes, treatments and its therapeutic limitations, approaching benign and malign presentations. Three illustrative cases are further presented, supporting the clinical problem under review.

CONCLUSION

Management of CAO still remains a challenge. The available options are not always effective nor free from complications. A new generation of costume-tailored airway stents, associated with stem cell-based therapy, could be an option in specific clinical situations.

Airway complications in lung transplantation

Airway complications (ACs) after lung transplantation remain an important source of morbidity and mortality despite significant advances in the surgical technics, leading to increased cost, and decrease quality of life. The incidences of ACs after lung transplantation range from 2% to 33%, even though most transplant centers have reported rates in the range of 7% to 8%. However, the reported rate of ACs has been inconsistent as a result of a lack of standardized airway definitions and grading protocols before the recent 2018 International Society for Heart and Lung Transplantation (ISHLT) proposed consensus guidelines on ACs after lung transplantation. The ACs include stenosis, perioperative and postoperative bronchial infections, bronchial necrosis and dehiscence, excess granulation tissue, and tracheobronchomalacia (TBM). Anastomosis infection, necrosis, or dehiscence typically develops within the first month after lung transplantation. The most frequent AC after lung transplantation is bronchial stenosis. Several risk factors have been proposed to the development of ACs after lung transplantation, including surgical anastomosis techniques, hypoperfusion, infections, donor and recipient factors, immunosuppression agents, and organ preservation. ACs might be prevented by early recognition of the airway pathology, using advance medical management, and interventional bronchoscopy procedures. Balloon bronchoplasty, cryotherapy, laser photo resection, electrocautery, high-dose endobronchial brachytherapy, and bronchial stents placement are the most frequent interventional bronchoscopic procedures utilized for the management of ACs.

Obese Patients Undergoing Tracheobronchoplasty Have Excellent Outcomes

BACKGROUND

Tracheobronchoplasty (TBP) is the gold-standard treatment for severe symptomatic excessive central airway collapse (ECAC), however outcomes among obese patients are unknown.

METHODS

A retrospective, single-center analysis was conducted on consecutive patients undergoing TBP for severe symptomatic ECAC from 2003 to 2020. Demographics, comorbidities, functional status, and peri-operative complications were collected. Functional status was assessed with a six-minute walk test (6MWT). Health-related quality of life (HRQOL) was assessed with the St. George's Respiratory Questionnaire (SGRQ), Cough-Specific Quality of Life Questionnaire (CSQL), and modified Medical Research Council dyspnea scale (mMRC) at baseline and post-operatively. Wilcoxon rank-sum and chi-squared tests were used to compare outcomes between groups. A mixed-effects regression model compared 6MWT and HRQOL over time.

RESULTS

One-hundred and three patients underwent TBP with complete follow-up data. Thirty-four patients (33%) were obese (BMI ≥ 35 kg/m²). Baseline demographics were similar between obese and non-obese groups, however obese patients had worse pre-operative SGRQ and mMRC. Overall complication rates were similar (52.9% vs. 43.5%, p=0.36). At 3-months, there was no significant difference in SGRQ, CSQL, or 6MWT, however, mMRC was higher in obese patients (p=0.04). At 12 months, there was no significant difference in SGRQ, CSQL, mMRC, or 6MWT. Correcting for age, sex, and Charlson Comorbidity Index, a mixed-effects regression model demonstrated obesity was not an independent predictor for lower 6MWT or HRQOL.

CONCLUSIONS

Obese patients achieve similar improvement in HRQOL and functional capacity with comparable morbidity following TBP as non-obese patients. Obesity should not preclude patients with severe symptomatic ECAC from TBP.

Thermoablative Techniques for Excessive Central Airway Collapse: An Ex Vivo Pilot Study on Sheep Tracheal Tissue

BACKGROUND

Tracheobronchoplasty is the definitive treatment for patients with symptomatic excessive central airway collapse. This procedure is associated with high morbidity and mortality rates. Bronchoscopic techniques are an appealing alternative with less morbidity and the ability to apply it in nonsurgical patients. Although thermoablative methods have been proposed as treatment options to induce fibrosis of the posterior tracheobronchial wall, no studies have compared direct histologic effects of such methods. This study compared the effects of electrocautery, radiofrequency ablation, potassium titanyl phosphate laser, and argon plasma coagulation (APC) in the tracheobronchial tree in an ex vivo animal model.

METHODS

Four adult sheep cadavers were used for this study. Under flexible bronchoscopy, the posterior tracheal membrane was treated using different power settings on 4 devices. The airways were assessed for the presence of treatment-related histopathologic changes.

RESULTS

Histologic changes observed were that of acute thermal injury including: surface epithelium ablation, collagen fiber condensation, smooth muscle cytoplasm condensation, and chondrocyte pyknosis. No distinct histologic differences in the treated areas among different modalities and treatment effects were observed. APC at higher power settings was the only modality that produced consistent and homogenous thermal injury effects across all tissue layers with no evidence of complete erosion.

CONCLUSION

Although electrocautery, radiofrequency ablation, potassium titanyl phosphate laser, and APC all induce thermal injury of the airway wall, only APC at high power settings achieves this effect without complete tissue erosion, favoring potential regeneration and fibrosis. Live animal studies are now plausible.

Respiratory subtype of relapsing polychondritis frequently presents as difficult asthma: a descriptive study of respiratory involvement in relapsing polychondritis with 13 patients from a single UK centre

Introduction

Relapsing polychondritis is a rare multisystem vasculitis characterised by recurrent cartilage inflammation. Respiratory involvement, of which tracheobronchomalacia (TBM) is the commonest form, is difficult to treat and is linked to increased mortality. We describe 13 patients with respiratory involvement.

Methods

This is a retrospective study of all the patients with relapsing polychondritis at University Hospitals Coventry and Warwickshire NHS Trust (UHCW), a secondary care provider for ∼500 000. Only patients with respiratory involvement were included in this study.

Results

We identified 13 patients who fulfilled the inclusion criteria. Most patients were identified from the “difficult asthma” clinic. TBM was seen in 11 patients, whilst two patients had pleural effusions which resolved with immunosuppression and one patient had small airways disease. Computed tomography scans (inspiratory and expiratory) and bronchoscopy findings were useful in diagnosing TBM. Pulmonary function testing revealed significant expiratory flow abnormalities. All patients were treated with corticosteroids/disease-modifying anti-rheumatic drugs (DMARDs) and some were given cyclophosphamide or biological agents, although the response to cyclophosphamide (1 out of 4) or biologicals (2 out of 4) was modest in this cohort. Ambulatory continuous positive airway pressure ventilation was successful in four patients.

Conclusions

Relapsing polychondritis may be overlooked in “difficult asthma” clinics with patients having TBM (not asthma) and other features of relapsing polychondritis. Awareness of this condition is crucial to enable early diagnosis and interventions to reduce the risk of life-threatening airway collapse. A number of patients respond well to DMARDs and are able to minimise corticosteroid use.

Tracheobronchomalacia can present as “difficult asthma” and can be associated with relapsing polychondritis. Optimal management of relapsing polychondritis is through medical treatments and support for the damaged airway through positive airway pressure.https://bit.ly/2JGoq23

3D Printed Biomimetic PCL Scaffold as Framework Interspersed With Collagen for Long Segment Tracheal Replacement

The rapid development of tissue engineering technology has provided new methods for tracheal replacement. However, none of the previously developed biomimetic tracheas exhibit both the anatomy (separated-ring structure) and mechanical behavior (radial rigidity and longitudinal flexibility) mimicking those of native trachea, which greatly restricts their clinical application. Herein, we proposed a biomimetic scaffold with a separated-ring structure: a polycaprolactone (PCL) scaffold with a ring-hollow alternating structure was three-dimensionally printed as a framework, and collagen sponge was embedded in the hollows amid the PCL rings by pouring followed by lyophilization. The biomimetic scaffold exhibited bionic radial rigidity based on compressive tests and longitudinal flexibility based on three-point bending tests. Furthermore, the biomimetic scaffold was recolonized by chondrocytes and developed tracheal cartilage in vitro. In vivo experiments showed substantial deposition of tracheal cartilage and formation of a biomimetic trachea mimicking the native trachea both structurally and mechanically. Finally, a long-segment tracheal replacement experiment in a rabbit model showed that the engineered biomimetic trachea elicited a satisfactory repair outcome. These results highlight the advantage of a biomimetic trachea with a separated-ring structure that mimics the native trachea both structurally and mechanically and demonstrates its promise in repairing long-segment tracheal defects.

Placement of self-expanding metallic tracheobronchial Y stent with laryngeal mask airway using conscious sedation under fluoroscopic guidance

Background

Central airway obstruction and fistula are treated with a tracheobronchial Y stent. In the currently used self‐expandable metal Y stents, the delivery system is 8 mm in diameter and requires either a 9 mm tracheal tube or rigid bronchoscope to enable airway control during insertion. In this study we present a novel technique of laryngeal mask airway (LMA) assisted Y stent insertion, enabling airway control during deployment of the Y stent.

Methods

All procedures using LMA in assisting Y stent insertions between 2014–2020 were reviewed. Data collected included demographics, clinical diagnosis and disease characteristics, indication, procedural success rates, clinical outcome and survival.

Results

A total of 10 patients with a median age of 61.5 years (range 37–73) underwent LMA assisted Y stent insertion. Indications for stent insertion were malignant disease with central airway obstruction or fistula. In all cases airway patency was achieved leading to improvement of symptoms and performance status. No procedural complications were reported. The median survival was 4.5 weeks (range: 2–26).

Conclusions

LMA assisted Y stent insertion enables airway control during the procedure. In comparison to silicone Y stent insertion, the procedure is less cumbersome, shorter in duration and does not require the use of general anesthesia or rigid bronchoscopy.

Key points

Significant findings of the study

LMA assisted Y stent insertion enables airway control during the implantation of metallic self‐expanding Y stent. The procedure does not require the use of general anesthesia or rigid bronchoscopy.

What this study adds

In this study we present the technique and outcomes of LMA assisted Y stent insertion. This method of Y stent insertion provides an additional treatment option for patients with central airway obstruction and fistula.

Central Airway Collapse, an Underappreciated Cause of Respiratory Morbidity

Dyspnea, cough, sputum production, and recurrent respiratory infections are frequently encountered clinical concerns leading patients to seek medical care. It is not unusual for a well-defined etiology to remain elusive or for the therapeutics of a presumed etiology to be incompletely effective. Either scenario should prompt consideration of central airway pathology as a contributor to clinical manifestations. Over the past decade, recognition of dynamic central airway collapse during respiration associated with multiple respiratory symptoms has become more commonly appreciated. Expiratory central airway collapse may represent the answer to this diagnostic void. Expiratory central airway collapse is an underdiagnosed disorder that can coexist with and mimic asthma, chronic obstructive pulmonary disease, and bronchiectasis. Awareness of expiratory central airway collapse and its spectrum of symptoms is paramount to its recognition. This review includes clear definitions, diagnostics, and therapeutics for this challenging condition. We performed a narrative review through the PubMed (MEDLINE) database using the following MeSH terms: airway collapse, tracheobronchomalacia, tracheomalacia, and bronchomalacia. We include reports from systematic reviews, narrative reviews, clinical trials, and observational studies from 2005 to 2020. Two reviewers evaluated potential references. No systematic reviews were found. A total of 28 references were included into our review. Included studies report experience in the diagnosis and/or treatment of dynamic central airway collapse; case reports and non-English or non-Spanish studies were excluded. We describe the current diagnostic dilemma, highlighting the role of dynamic bronchoscopy and tracheobronchial stent trial; outline the complex therapeutic options (eg, tracheobronchoplasty); and present future directions and challenges.

Interventional Pulmonology: A Brave New World

Interventional pulmonology is a dynamic and evolving field in respiratory medicine. Advances have improved the ability to diagnose and manage diseases of the airways. A shift toward early detection of malignant disease has generated a focus on innovative diagnostic techniques. With patient populations living longer with malignant and benign diseases, the role for interventional bronchoscopy has grown. In cancer groups, novel immunotherapies have improved the prospects of clinical outcomes and reignited a focus on optimizing patient performance status to enable access to anticancer therapy. This review discusses current and emerging diagnostic modalities and therapeutic approaches available to manage airway diseases.

Quality of life outcomes in tracheobronchomalacia surgery

Tracheobronchomalacia (TBM) is an obstructive airway disease characterized by laxity and redundancy of the posterior membrane of the main airways leading to dynamic airway collapse during exhalation. The gold standard for diagnosis is dynamic computed tomography (DCT) scan and dynamic flexible bronchoscopy (DFB). Patients with complete or near-complete collapse (>90% reduction in cross-sectional area) of the airway are possible candidates for surgical management. Central airway stabilization by tracheobronchoplasty (TBP) effectively corrects malacic airways and has demonstrated significant improvement in objective functional measures, which is often but not uniformly accompanied by equal improvement in health-related quality of life (HRQOL) metrics. This article reviews HRQOL instruments used to report outcomes after TBM surgery.

Tracheobronchomegaly, cough and recurrent chest infection: Mounier-Kuhn syndrome

A 49-year-old male ex-smoker was referred for recurrent chest infections requiring one course of antibiotics every winter, occurring over the last 20 years. Each episode is characterised by a productive cough with purulent sputum along with difficulty breathing, chest tightness and fatigue, but without haemoptysis. On some occasions, these symptoms were preceded by fever and rhinorrhoea. Each episode lasted ∼10 days and responded well to antibiotics. He had never been hospitalised for these infections, nor received a chest radiograph or sputum microbiology. He had been told that he developed episodes of pneumonia in his first year of life. Apart from these yearly infections, the patient was asymptomatic during the rest of the year.

Mounier-Kuhn Syndrome (MKS) is a rare disease characterised by recurrent chest infections, and dilation of the trachea and main bronchi, most likely to due to atrophy of elastic fibreshttps://bit.ly/3azhDjr

Internal fixation of the proximal tracheal self-expandable metallic stent (SEMS): migration prevention in high risk patients

Airway stenting provides an important treatment option for patients with proximal tracheal stenosis. However, the risk of migration remains a major challenging problem. In our report we describe the internal fixation of SEMS in 3 patients with proximal tracheal stenosis due to variable causes. The fixation was performed in different situations including: prophylaxis to prevent the stent migration, fixation due to displacement of the stent during insertion and finally internal fixation of migrated tracheal stent.

Acute Airway Obstruction and Cardiopulmonary Arrest due to Tracheomalacia Caused by Megaesophagus Compression Secondary to Achalasia

We report the case of an 80-year-old woman who presented one episode of cardiopulmonary arrest and two episodes of acute airway obstruction. We found in this patient the presence of tracheomalacia caused by megaesophagus compression secondary to achalasia probably responsible for episodes of acute airway obstruction and cardiopulmonary arrest.

Anesthetic Approach to Postpneumonectomy Syndrome

Postpneumonectomy syndrome is a rare complication in patients who have previously had a pneumonectomy. Over time, the mediastinum may rotate toward the vacant pleural space, which can cause extrinsic airway and esophageal compression. As such, these patients typically present with progressive dyspnea and dysphagia. There is a paucity of reports in the anesthesiology literature regarding the intraoperative anesthetic approach to such rare patients. We present a case of an 18-year-old female found to have postpneumonectomy syndrome requiring thoracotomy with insertion of tissue expanders. Our case report illustrates the complexities involved in the care of these patients with regards to airway management, ventilation concerns, and potential for hemodynamic compromise. This case report underscores the importance of extensive multidisciplinary planning.

Airway stenting: Technological advancements and its role in interventional pulmonology

AS offers rapid and sustained relief of symptoms in most patients treated for malignant or benign CAO and can also be curative in itself in cases of benign tracheobronchial stenosis. In the past 30 years, this field has seen significant progress, from the misuse of vascular non-covered metallic stents to the development of silicone airway stents with an increasingly large panel of shapes and of hybrid, partially or fully covered, SEMS customized to the airways. This study aims to offer an overview on: (i) the respective advantages and drawbacks of these two main categories of devices; (ii) the main indications for AS and the rationale behind the choice of stent in each situation; and (iii) the main promises borne from the progress made in the field in the past few years, including the development of drug-eluting, biodegradable or patient-specific customized AS.

Esophageal Trachea, a Unique Foregut Malformation Requiring Multistage Surgical Reconstruction: Case Report

Abnormal connections between the esophagus and low respiratory tract can result from embryological defects in foregut development. Beyond well-known malformations, including tracheo-esophageal fistula and laryngo-tracheo-esophageal cleft, rarer anomalies have also been reported, including communicating bronchopulmonary foregut malformations and tracheal atresia. Herein, we describe a case of what we have called "esophageal trachea," which, to our knowledge, has yet to be reported. A full-term neonate was born in our institution presenting with a foregut malformation involving both the middle esophagus and the distal trachea, which were found to be longitudinally merged into a common segment, 3 cm in length, located just above the carina and consisted of esophageal tissue without cartilaginous rings. At birth, the esophagus and trachea were surgically separated via right thoracotomy, the common segment kept on the tracheal side only, creating a residual long-gap esophageal atresia. The resulting severe tracheomalacia was treated via simultaneous posterior splinting of such diseased segment using an autologous pericardium patch, as well as by anterior aortopexy. Terminal esophagostomy and gastrostomy were created at that stage due to the long distance between esophageal segments. Between ages 18 and 24 months, the patient underwent native esophageal reconstruction using a multistage traction-and-growth surgical strategy that combined Kimura extra-thoracic esophageal elongations at the upper esophagus and Foker external traction at the distal esophagus. Ten months after esophageal reconstruction, prolonged, refractory, and severe tracheomalacia was further treated via anterior external stenting using a semitubular ringed Gore-Tex® prosthesis, through simultaneous median sternotomy and tracheoscopy. Currently, 2 years after the last surgery, respiratory stabilization, and full oral feeding were stably achieved. Multidisciplinary management was crucial for assuring lifesaving procedures, correctly assessing anatomy, and planning for multiple sequential surgical approaches that aimed to restore long-term respiratory and digestive functions.

Upper airway wheezing: Inducible laryngeal obstruction vs. excessive dynamic airway collapse

There are multiple causes of dyspnea upon exertion in young, healthy patients to primarily include asthma and exercise-induced bronchospasm. Excessive dynamic airway collapse (EDAC) describes focal collapse of the trachea or main bronchi with maintained structural integrity of the cartilaginous rings. It is commonly associated with pulmonary disorders like bronchiectasis, chronic obstructive pulmonary disease and asthma. It is believed to result secondary to airway obstruction in these conditions. While uncommon in young, healthy adults, it has recently been found as a cause of dyspnea in this population. Inducible laryngeal obstruction (ILO) is an umbrella term that describes an induced, intermittent upper airway impediment. While ILO is found in 10% of young patients with exertional dyspnea, it is primarily inspiratory in nature due to paradoxical closure of the glottis or supraglottis. This report highlights the presentation of a United States Army soldier who after a deployment was given a diagnosis of asthma, later found to have ILO and was subsequently diagnosed with concurrent EDAC. We follow up with a literature review and discussion of symptomatology, diagnosis, exercise bronchoscopy, and treatment modalities for both EDAC and ILO.

Tracheobronchomalacia and Excessive Dynamic Airway Collapse

Tracheobronchomalacia (TBM) and excessive dynamic airway collapse (EDAC) are more frequently being recognized as the etiology of multiple types of respiratory complaints from chronic cough to exertional syncope to recurrent infections. Identification of these conditions requires a high suspicion, as well as a thorough history and physical examination. Dynamic computed tomography imaging and bronchoscopic evaluation are integral in achieving an accurate diagnosis. Once recognized, treatment ranges from addressing underlying contributing conditions to surgical stabilization of the airway. Referral to an institution familiar with the evaluation and treatment of TBM/EDAC is essential for the appropriate management of these conditions.

Expiratory reactance abnormalities in patients with expiratory dynamic airway collapse: a new application of impulse oscillometry

Expiratory dynamic airways collapse (EDAC) is a condition that affects the central airways; it is not well characterised physiologically, with relatively few studies. We sought to characterise impulse oscillometry (IOS) features of EDAC in patients with normal spirometry. Expiratory data were hypothesised to be the most revealing. In addition, we compared IOS findings in chronic obstructive pulmonary disease (COPD) patients with and without EDAC.

EDAC was identified at bronchoscopy as 75–100% expiratory closure at the carina or bilateral main bronchi. Four patient groups were compared: controls with no EDAC and normal lung function; lone EDAC with normal lung function; COPD-only patients; and COPD patients with EDAC.

38 patients were studied. Mean IOS data z-scores for EDAC compared to controls showed significantly higher reactance (X) values including X at 5 Hz, resonance frequency and area under the reactance curve (A_X). EDAC showed significantly greater expiratory/inspiratory differences in all IOS data compared to controls. Stepwise logistic regression showed that resonant frequency best discriminated between EDAC and normal control, whereas classification and regression tree analysis found A_X ≥3.523 to be highly predictive for EDAC in cases with normal lung function (14 out of 15 cases, and none out of eight controls).

These data show a new utility of IOS: detecting EDAC in patients with normal lung function.

Central airway expiratory dynamic airway collapse can be “silent” on breathing tests, but impulse oscillometry can reveal ithttp://ow.ly/9oIb30lIOka

The Prevalence of Gastroesophageal Reflux in Patients With Excessive Central Airway Collapse

BACKGROUND

Gastroesophageal reflux (GER) is increasingly recognized as an exacerbating or causal factor in several respiratory diseases. There is a high prevalence of GER in infants with airway malacia. However, such data are lacking in adults.

METHODS

This retrospective study was conducted to determine the relationship between GER and excessive central airway collapse (ECAC). The study included consecutive patients with ECAC referred to the Complex Airway Center at Beth Israel Deaconess Medical Center who underwent esophageal pH testing for GER between July 2014 and June 2018.

RESULTS

Sixty-three of 139 patients with ECAC (45.3%) had documented GER as shown by an abnormal esophageal pH test result. The mean DeMeester score was 32.2, with a symptom association probability of 39.7% of GER-positive patients. Twenty-nine of 63 patients (46%) with GER reported improvement in respiratory symptoms following maximal medical therapy or antireflux surgery without requiring further treatment for ECAC.

CONCLUSIONS

GER is prevalent among patients with ECAC, and aggressive reflux treatment should be considered in these patients prior to considering invasive airway procedures or surgery.

Unveiling the fate of adhering bacteria to antimicrobial surfaces: expression of resistance-associated genes and macrophage-mediated phagocytosis

Since most antibacterial coatings reported to fight biomaterial-associated infections (BAI) fail in completely preventing bacterial colonization, it is crucial to know the impact of that small fraction of adhered bacteria in BAI recrudescence. This study aims to understand the fate of Staphylococcus aureus able to adhere to an antimicrobial coating previously developed, in terms of potential development of bacterial resistance and their macrophage-mediated phagocytosis. Antimicrobial coating comprised the co-immobilization of Palm peptide and DNase I onto polydimethylsiloxane. Expression of genes associated to resistance and virulence mechanisms showed that cells in contact with antimicrobial surfaces for a long period of 30 days, exhibit genes equally or less expressed, as compared to cells recovered from control surfaces. Recovered cells also exhibit the same susceptibility patterns, which strengthens the evidence of no resistance development. Remarkably, cells adhered to modified surfaces shows a reduced metabolic activity upon vancomycin treatment unlike the cells found on control surfaces, which can be identified as a clinical opportunity for prophylactically administration after implant surgery. Furthermore, results highlight that functionalization of PDMS with Palm and DNase I should not compromise the action of host immune cells. The overall results reinforce the potential of this antimicrobial strategy to fight BAI.

Applications and challenges of using 3D printed implants for the treatment of birth defects

Pediatric implants are a special subclass of a vast number of clinically used medical implants, uniquely designed to address the needs of young patients who are at the onset of their developmental growth stage. Given the vulnerability of the implant receiver, it is crucial that the implants manufactured for small children with birth-associated defects be given careful considerations and great attention to design detail to avoid postoperative complications. In this review, we focus on the most common types of medical implants manufactured for the treatment of birth defects originating from both genetic and environmental causes. Particular emphasis is devoted toward identifying the implant material of choice and manufacturing approaches for the fabrication of pediatric prostheses. Along this line, the emerging role of 3D printing to enable customized implants for infants with congenital disorders is presented, as well as the possible complications associated with prosthetic-related infections that is prevalent in using artificial implants for the treatment of birth malformations.