Endobronchial valve therapy for severe emphysema: an overview of valve-related complications and its management

A 6-year experience of Zephyr endobronchial valves for severe emphysema in an Australian single-centre cohort

BACKGROUND

Endobronchial valve (EBV) insertion for lung volume reduction is a management option for patients with severe emphysema. One-way valves cause lobar deflation and improve lung function, exercise capacity and quality of life.

AIMS

To retrospectively analyse and compare the outcomes of the first 57 patients treated with EBVs between 2015 and 2021 at the Royal Adelaide Hospital to international standards.

METHODS

Clinical outcomes of forced expiratory volume in 1 s (FEV1), residual volume (RV), treated lobe volume reduction (TLVR) and 6-min walk distance (6MWD) at 3, 6 and 12 months after valve insertion were reviewed against established minimally clinically important differences (MCIDs). Complications and subjective breathlessness measured by Borg scores were also reviewed.

RESULTS

Fifty-seven patients were included. At 12 months, 77.2% achieved TLVR. FEV1 improved by 170 mL (95% confidence interval (CI): 100-250, P < 0.001), 80 mL (95% CI: 10-150, P = 0.019) and 40 mL (95% CI: -60 to 130, P 0.66) at 3, 6 and 12 months respectively. RV improved by -610 mL (95% CI: -330 to -900, P < 0.0001) at 3 months, -640 mL (95% CI: -360 to -920, P < 0.0001) at 6 months and -360 mL (95% CI: -60 to -680, P = 0.017) at 12 months. 6MWD improved by 57.34 m (95% CI: 36.23-78.45, P < 0.0001) and 44.93 m (95% CI: 7.19-82.67, P = 0.02) at 3 and 6 months. Borg score improved by -0.53 (95% CI: 0.11 to -1.2, P = 0.11) and -0.49 (95% CI: 0.17 to -1.15, P = 0.16) at 3 and 6 months. Complication rates aligned with international standards with mucous/infection (26.3%) and pneumothorax (17.5%) as the most common. Subgroup analysis signalled improved outcomes in patients with heterogeneous emphysema.

CONCLUSION

Our study represents the first publicly funded Australian analysis of EBVs. The results align with international prospective trials demonstrating improved lung function and exercise capacity. Australians with severe emphysema and gas trapping should be referred to a multidisciplinary centre for consideration of EBVs.

Optimizing clinical outcomes for bronchoscopic lung volume reduction with Zephyr® valves

Bronchoscopic lung volume reduction treatment with Zephyr one-way valves is an effective guideline-based treatment option for patients with severe emphysema and hyperinflation. However, in some cases the treatment response is less than anticipated or there might be a loss of initial treatment effect. Reasons for the lack of response can include incorrect assessment of collateral ventilation, improper valve placement, or patient related factors. Loss of initial benefit can be due to granulation tissue formation and subsequent valve dysfunction, or there may be side effects such as excessive coughing or infectious problems. Careful follow-up after treatment with valves is important and evaluation with a CT scan and/or bronchoscopy is helpful if there is no improvement after treatment or loss of initial benefit. This paper aims to describe the most important causes and provide a strategy of how to approach and manage these patients.

Design of the multicentre randomised controlled BENTO trial to demonstrate patient-relevant benefit of bronchoscopic lung volume reduction using thermal vapour ablation in the German healthcare system for patients with upper lobe emphysema: a study protocol

INTRODUCTION

Application of vapour ablation as a novel approach to lung volume reduction has positive effects in patients with severe emphysema. The BENTO study is a randomised, controlled, open, multicentre trial, to assess the effects of bronchoscopic thermal vapour ablation (BTVA) in the German healthcare system.

METHODS AND ANALYSIS

Patients with bilateral heterogeneous emphysema of the upper lobes in Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage 3/4 will be enrolled in this trial and will receive either standard medical management alone (according to GOLD guidelines) or BTVA treatment with the InterVapor system together with standard medical management. Patients will be randomised in a 2:1 ratio (treatment group:control group). A total of 224 patients will be enrolled at 15 study sites. The primary endpoint is the change in patient-reported disease-specific quality of life, as measured by the St George's Respiratory Questionnaire for chronic obstructive pulmonary disease patients between randomisation and the 9-month follow-up visit. Secondary endpoints include adverse events, mortality, vital status, changes in lung function parameters, exercise capacity and other efficacy measures at 3, 9 and 12 months.The BENTO trial was commissioned by the German Federal Joint Committee, to demonstrate that this approach is an efficient and safe treatment option in the German healthcare system.

ETHICS AND DISSEMINATION

The protocol has been approved by the lead ethics committee in Germany (Ethics Committee of the Medical Faculty of Heidelberg) and until present also by the following ethics committees: Ethics Committee of the Medical Faculty of Duisburg-Essen, Ethics Committee of the Medical Faculty of Martin-Luther-University Halle-Wittenberg, Ethics Committee of the State Medical Association of Hessen, Ethics Commission of the State Office for Health and Social Affairs of the State of Berlin, Ethics Committee of the Medical Faculty of Greifswald. The results will be published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT05717192.

Lung volume reduction surgery is safe and feasible after initial endobronchial valve treatment for emphysema patients

OBJECTIVES

Bronchoscopic lung volume reduction with endobronchial valves is a guideline treatment leading to improved pulmonary function, exercise tolerance and quality of life, in patients with advanced emphysema, severe hyperinflation and no collateral ventilation. After valve treatment, loss of the initial lung volume reduction effect can occur, as well as local valve-induced complications such as persistent haemoptysis. In these cases, a surgical lobectomy can be considered to achieve similar efficacy outcomes. We evaluated the safety and feasibility of a video-assisted thoracoscopic surgery lobectomy after valve treatment.

METHODS

This single-centre retrospective study included patients who underwent an elective lobectomy after previous valve treatment. Data were evaluated for safety and efficacy for the additional surgical procedure.

RESULTS

Twenty-one patients [73% female, median age 67 (7) years, forced expiratory volume in 1 s 29 (7) %pred, and residual volume 223 (58) %pred] were included. There was no 90-day mortality and there were no postoperative intensive care admissions. Pulmonary infections (14%) and prolonged air leak (14%) were the most common complications. In patients who underwent surgery due to loss or lack of effect of valve treatment, a lobectomy led to a significant improvement in pulmonary function; median forced expiratory volume in 1 s +75 (193) ml (P < 0.013), forced vital capacity +450 (572) ml (P = 0.001), residual volume -665 (715) ml (P = 0.005). In patients who underwent a lobectomy because of complications of valve treatment, all complications were resolved after surgery.

CONCLUSIONS

We demonstrate that an elective lobectomy after an initial valve treatment is safe and feasible and restores the lung volume reduction effect.

Management of Refractory Chronic Obstructive Pulmonary Disease: A Review

Chronic obstructive pulmonary disease (COPD) is a common condition with an estimated prevalence of 12% in adults over the age of 30 years worldwide. COPD is a leading cause of morbidity and mortality globally, with a substantial economic and social burden. There are an estimated 3 million deaths annually due to COPD. However, most of the patients with COPD respond to routine interventions like bronchodilator therapy, assessing supplemental oxygen needs, smoking cessation, vaccinations, and pulmonary rehabilitation. There is a significant number of patients who unfortunately progress to have persistent symptoms despite these interventions. Refractory COPD is not yet formally defined. Patients with severe persistent symptoms or exacerbations despite appropriate care can be considered to have refractory COPD. Managing refractory COPD needs a multidimensional approach. In this review article, we will discuss essential interventions like ensuring adequate inhaler techniques, exploring the need for non-invasive ventilatory support, use of chronic antibiotics and phosphodiesterase inhibitors to advanced therapies like bronchoscopic lung volume reduction surgery, and the upcoming role of anti-IL5 agents in managing patients with refractory COPD. We will also discuss non-pharmacologic interventions like psycho-social support and nutritional support. We will conclude by discussing the palliative care aspect of managing patients with refractory COPD. Through this review article, we aim to better the approach to managing patients with refractory COPD and discuss new upcoming therapies.

First in vivo Experiment with PulmValve Endobronchial Valve: Feasibility, Efficiency, and Safety

INTRODUCTION

Endoscopic lung volume reduction with endobronchial valves has been widely recognized for treating hyperinflation in advanced chronic obstructive pulmonary disease and emphysema patients. The main challenges include the technical complexity of upper lobe implantation and the number of endobronchial valves required. These issues might be addressed by placing larger diameter valves in the lobar bronchus. This study evaluated the feasibility, efficiency, and safety of the new valve PulmValve (model PV-13) in porcine models.

METHODS

Six PV-13 valves were bronchoscopically implanted into the caudal lobe bronchus of six healthy pigs. The procedure time, valve deployment, and removability were recorded. Follow-up examinations included blood tests, chest CT scans, and bronchoscopy at 30 min, 14 days, 28 days, and 84 days post-procedure, with necropsy and pathological evaluations after the final follow-up examination.

RESULTS

The successful in vivo deployment and removal of PV-13 valves was established, with a median procedure time of 6.5 min. The distal lung volume reduction was evident at 30 min post-operation and was persistently monitored on day 84. No migration or malfunction of any PV-13 valves was detected, but a mild angle deviation was found in 3 cases. Coughing was observed in four pigs within the first 7 days and localized granulation tissue was observed in all pigs. No cases of pneumothorax, diffuse pneumonia, or hemoptysis were detected.

CONCLUSIONS

In this study, we report the successful implantation and removal of a new valve PulmValve in a short operation time. Complete lobar atelectasis was induced without device migration, malfunction, or severe complications. Further studies are warranted to evaluate the long-term, sustained effects and potential benefits in human patients.

Surgical and bronchoscopic pulmonary function-improving procedures in lung emphysema

COPD is a highly prevalent, chronic and irreversible obstructive airway disease without curative treatment. Standard therapeutic strategies, both non-pharmacological and pharmacological, have only limited effects on lung function parameters of patients with severe disease. Despite optimal pharmacological treatment, many patients with severe COPD still have a high burden of dyspnoea and a poor quality of life. If these patients have severe lung emphysema, with hyperinflation as the driver of symptoms and exercise intolerance, lung volume reduction may be an effective treatment with a significant impact on lung function, exercise capacity and quality of life. Currently, different lung volume reduction approaches, both surgical and bronchoscopic, have shown encouraging results and have been implemented in COPD treatment recommendations. Nevertheless, choosing the optimal lung volume reduction strategy for an individual patient remains challenging. Moreover, there is still room for improving durability of effect and safety in all available procedures. Ongoing and innovative research is essential to push this field forwards. This review provides an overview of results and limitations of the current lung volume reduction options for patients with severe lung emphysema and hyperinflation.

Endobronchial valve treatment in chronic obstructive pulmonary disease: A qualitative study of patients' expectations

Objectives

Endobronchial valve (EBV) treatment is a treatment option for selected patients with severe chronic obstructive pulmonary disease (COPD) to reduce dyspnea and improve quality of life. However, the procedure is associated with risk of complications, and not all patients achieve the expected outcomes. The present study explores patients' expectations while waiting for EBV treatment.

Methods

Fifteen patients accepted for EBV treatment at Aarhus University Hospital in Denmark from October 2020 to June 2021 participated in a 30-min, semi-structured interview about (1) the experience of living with COPD and (2) expectations regarding EBV.

Results

Four themes were identified: a life of reduced quality; hopes and expectations; information about EBV; and perception of risks. Most patients described their lives as not worth living, and they hoped that EBV would give them their physical and social lives back, while also being aware that EBV would probably not work miracles. Patients' information seeking was influenced by their hopes and expectations to the treatment. They filtered out negative information, focusing on the hope for a positive outcome. This made them willing to run the risk of complications.

Conclusion

Living a life of considerably reduced quality, patients might have an increased focus on potential positive effects of EBV treatment while filtering out information about potential side effects. This might bias their decision-making process.

Hypoxemia After Endobronchial Valve Deployment for Persistent Air Leak

Endobronchial valves (EBVs) are a novel, minimally invasive bronchoscopic management technique for persistent air leaks that fail conservative therapy. Currently, 2 EBVs are available in the United States: the Spiration Valve System (Olympus, Redmond, WA) and the Zephyr Valve (Pulmonx, Redwood, CA). These valves are Food and Drug Administration-approved to reduce hyperinflation in emphysematous patients via bronchoscopic lung-volume reduction. However, more recently, the Spiration Valve has been granted a compassionate use exemption through the Food and Drug Administration for persistent postsurgical air leaks. Despite their popularity, these devices are not free from side effects. As an anesthesiologist, it is vital to be aware of the pathophysiology of this patient population so that safe and effective anesthetics may be provided during valve placement. Here, the use of EBVs is discussed in a patient who presented with a persistent air leak after a transthoracic needle aspiration that failed treatment due to persistent hypoxemia, warranting EBV removal.

The development, validation, and in vivo testing of a high-precision bronchial epithelial lining fluid sampling device

Introduction

Analysis of respiratory biomarkers or pharmaceutical drug concentrations in bronchial epithelial lining fluid (bELF) using a high-precision sampling method is crucial for effective clinical respiratory diagnostics and research. Here, we utilized a cellulose matrix as an absorptive probe for bELF sampling, subsequently testing the design of a device and sampling technique in vivo.

Methods

The absorptive matrix [Whatman® qualitative filter paper (Grade CF-12)] was first tested through tissue-contact experiments on porcine airway tissue. The absorption and elution capacity of the matrix, as well as the laboratory processing and analysis method, was validated with a range of Interleukin-8 (CXCL8) and C-Reactive protein (CRP) stock solutions. Subsequently, the device's design was optimized for universal in-house production and both, safe and efficient sampling. The airway sampling method was then tested in a group of 10 patients with Chronic Obstructive Pulmonary Disease (COPD). For each patient, a bELF sample was obtained using the newly developed bELF probe, as well as a reference 20 mL saline bronchial wash sample. Supernatants were assessed, using an immunoassay, for levels of the pro-inflammatory markers CXCL8, Myeloperoxidase (MPO), and CRP. The bELF samples were compared to bronchial wash.

Results

The Whatman® qualitative filter paper (Grade CF-12) bELF probes adhered to porcine airway tissue, softening slightly upon wetting. The material maintained architectural integrity following the removal of the probes, leaving no residual fibers on the porcine airway mucosa. The bELF probe design was optimized for bronchoscopic delivery and in-house production. On average, a fully saturated bELF probe carried 32 μL of protein-rich fluid. The mean return of CXCL8 and CRP from samples collected from a serial dilution series (1, 5, 10, 20 ng/mL) was 69% (range 48%-87%). The bELF probe detected, on average, 7 (MPO), 14 (CRP), and 59 (CXCL8) times higher equivalent inflammatory protein concentrations in the collected bELF probe samples compared to the bronchial wash.

Conclusion

The bELF probe is an effective absorptive technology for high-precision bELF sampling without dilution. With a simple in-house production procedure and bronchoscopic sampling technique, this method can be introduced in any bronchoscopic center for a consistent sampling of bELF.

Host-device interactions: exposure of lung epithelial cells and fibroblasts to nickel, titanium, or nitinol affect proliferation, reactive oxygen species production, and cellular signaling

Endoscopic implantation of medical devices for the treatment of lung diseases, including airway stents, unidirectional valves and coils, is readily used to treat central airway disease and emphysema. However, granulation and fibrotic tissue formation impairs treatment effectiveness. To date little is known about the interaction between implanted devices, often made from metals, such as nickel, titanium or nitinol, and cells in the airways. Here, we study the response of lung epithelial cells and fibroblasts to implant device materials. The adhesion and proliferation of bronchial epithelial cells and lung fibroblasts upon exposure to 10 × 3 × 1 mm pieces of nickel, titanium or nitinol is examined using light and scanning electron microscopy. Pro-inflammatory cytokine mRNA expression and release, signaling kinase activity and intracellular free radical production are assessed. Nitinol, and to a lesser extent nickel and titanium, surfaces support the attachment and growth of lung epithelial cells. Nitinol induces a rapid and significant alteration of kinase activity. Cells directly exposed to nickel or titanium produce free radicals, but those exposed to nitinol do not. The response of lung epithelial cells and fibroblasts depends on the metal type to which they are exposed. Nitinol induces cellular surface growth and the induction of kinase activity, while exposure of lung epithelial cells to nickel and titanium induces free radical production, but nitinol does not.

Endobronchial Valve Replacements in Patients with Advanced Emphysema After Endoscopic Lung Volume Reduction

Purpose

Up to 41% of patients with endobronchial valve implantation need revision bronchoscopies and valve replacements most likely due to valve dysfunction or lack of benefit. So far, no data is available whether valve replacements lead to the desired lobar volume reduction and therapy benefit.

Patients and Methods

We conducted a single-center retrospective analysis of patients with endobronchial valve implantation and at least one valve replacement. Indications and number of revision bronchoscopies and valve replacements were evaluated. Therapy benefit regarding lung function and exercise capacity as well as development of complete lobar atelectasis was investigated and possible predictors identified.

Results

We identified 73 patients with 1-12 revision bronchoscopies and 1-5 valve replacements. The main indication for revision bronchoscopy in this group was lack of therapy benefit (44.2%). Lung function and exercise capacity showed improvements in about one-third of patients even years after the initial implantation. A total of 26% of all patients showed a complete lobar atelectasis at the end of the observation period, 56.2% had developed lung volume reduction. The logistic regression revealed the development of a previous complete lobar atelectasis as predictor for a complete lobar atelectasis at final follow-up. Oral cortisone long-term therapy was also shown as predictive factor. The probability for a final complete lobar atelectasis was 69.2% if a lobar atelectasis had developed before.

Conclusion

Valve replacements are more likely to be beneficial in patients who develop a re-aeration of a previous lobar atelectasis following valve implantation. Every decision for revision bronchoscopy must be taken carefully.

Bronchoscopic Management of COPD and Advances in Therapy

Chronic Obstructive Pulmonary Disease (COPD) is a highly prevalent and morbid disease marked by irreversible structural changes in the lungs. Bronchoscopic therapies have significantly expanded the treatment armamentarium for patients with persistent symptoms by reducing the physiologic detriments of hyperinflation in a less invasive fashion than surgical lung volume reduction. The spectrum of bronchoscopic techniques to reduce hyperinflation includes endobronchial valves, coils, thermal ablation, and biologic sealants. Other therapies focus on reducing parasympathetic tone and mucus hypersecretion and include targeted lung denervation, bronchial rheoplasty, and cryospray techniques. In this article, we will review the variety of techniques for bronchoscopic lung volume reduction, both established and investigational, along with their respective benefits and complications and will briefly review other investigational therapies for COPD.

Impact of pneumothorax-like pulmonary collapse caused by rapid bronchial obstruction: A case report of pneumothorax ex vacuo

We report two cases of pulmonary collapse that simulated pneumothorax on computed tomographic images and were caused by rapid complete bronchial obstruction. One patient was a 77-year-old woman with sudden dyspnea, and the other was an 83-year-old woman with sudden dyspnea who was infected with influenza A virus. Chest computed tomography revealed lobular complete atelectasis with an almost complete expansion of the other lobes of the right lung. Some air space in the right pleural cavity was also observed. Both cases were diagnosed as "pneumothorax" by primary doctors. We noted the disappearance of air density in the lumen of the right bronchus in both cases. We performed bronchoscopy before thoracic drainage and removed the obstruction. Immediately, the obstructed pulmonary lobes expanded, and the air space in the pleural cavity disappeared without thoracic drainage. In the literature, this pneumothorax-like pulmonary collapse is called as "pneumothorax ex vacuo."

Clinical Impact of Compensatory Hyperinflation of the Nontreated Adjacent Lobe After Bronchoscopic Lung Volume Reduction with Valves

Background

Bronchoscopic lung volume reduction (BLVR) with endobronchial valves (EBV) can be a successful treatment for end-stage emphysema patients. The reduction of hyperinflation enhances ventilatory mechanics and diaphragm function. Understanding predictors for treatment success is crucial for further improvements.

Purpose

The aim of this study was to assess the effect of the target lobe volume reduction (TLVR) in relation to the ipsilateral lung volume reduction (ILVR), affected by the compensatory expansion of the adjacent lobe, on the outcome after BLVR with valves.

Patients and Methods

The volumetric relationship of ILVR% to TLVR%, addressed as Reduction Ratio (R), was recorded in 82 patients and compared to changes in lung function, physical performance and quality of life. A small value for R implies a relatively low volume reduction of the ipsilateral lung (ILVR) compared to the volume reduction of the target lobe (TLVR). Additionally, the minimal clinically important difference (MCID) for R was calculated.

Results

Patients with a smaller Reduction Ratio (R <0.2) showed minor improvements at the 3 months follow-up compared to patients with R ≥0.2 (mean changes of 39 mL (5.8%), –395 mL (–4.9%) and 96 mL (7.1%) versus 231 mL (33%), –1235 mL (–20%) and 425 mL (29%) in the forced expiratory volume in 1s (FEV₁), residual volume (RV) and inspiratory vital capacity (IVC), respectively, and –3 m and 0 points versus 20.4 m and –3.4 points in the 6-minute-walking-distance (6MWD) and COPD assessment test (CAT) score respectively). With a combined value of 0.185, a MCID for R was calculated with established anchors (FEV₁, RV, and 6MWD) for emphysema patients.

Conclusion

Extensive compensatory hyperinflation of the adjacent non-treated lobe after BLVR results in decreased ILVR, which is responsible for a lack of meaningful improvements in ventilatory mechanics and clinical outcome, despite technically successful lobe volume reduction.

Meta-analysis and Systematic Review of Bronchoscopic Lung Volume Reduction Through Endobronchial Valves in Severe Emphysema

BACKGROUND

Pharmacologic therapeutics for advanced emphysema have limited benefit. Bronchoscopic lung volume reduction with endobronchial valves (EBVs) have reported improvements in lung function, breathlessness, and quality of life through randomized clinical trials, with less morbidity as comparted to Surgical Lung volume Reduction. We here present a Meta-analysis and systematic review of bronchoscopic lung volume reduction in advanced chronic obstructive lung disease patients.

METHODS

PubMed (NLM), Embase (Elsevier), and Web of Science (Clarivate Analytics) search was conducted using a combination of keywords and subject headings. The search was confined to the last 15 years and was completed on October 23, 2020. Only placebo-controlled randomized control trials of emphysema patients with EBV were included. Quality assessment was done by 2 independent reviewers.

RESULTS

Nine studies were included for the meta-analysis with a total number of 1383 patients of whom 888 received EBV and 495 standard of care (SOC) medications. Our Metanalysis show statistically significant improvement in forced expiratory volume in first second, percentage forced expiratory volume in first second, St. George's respiratory questionnaire, and 6-minute walk distance in EBV group compared with SOC. Residual volume had statistically significant reduction after EBV placement compared with SOC. These differences continued to be present during short-term (<=6 mo) and long-term follow-up (>=6 mo). These improvements were even higher when the EBV patients'. Collateral ventilation was negative/fissure was intact (CV-/FI >90%). The rate of hemoptysis and pneumothorax was higher in the EBV group compared with SOC, however, did not lead to increased fatal outcomes.

CONCLUSION

In conclusion, EBV has favorable effects on patients' outcomes in patients who have heterogeneous emphysema particularly with no collateral ventilation.

Bronchoscopic Lung Volume Reduction for Emphysema: Review and Update

In carefully selected patients with severe chronic obstructive pulmonary disease, characterized by emphysema and hyperinflation, lung volume reduction is an option to reduce lung hyperinflation, improve lung function, quality of life, and exercise capacity. Currently, there are several bronchoscopic and surgical treatment options to achieve lung volume reduction. It is important to carefully phenotype these patients, to select the optimal treatment option, with consideration of possible adverse events or contraindications, and it is highly recommended to discuss these treatment strategies in a multidisciplinary team. The treatment with one-way endobronchial valves has been investigated most extensively and more data are available regarding the treatment of more "marginal cases," or subsequent lung volume reduction surgery. Other bronchoscopic lung volume reduction options include treatment with coils, thermal vapor ablation, and sclerosant agents. In this review, we aim to summarize the current clinical evidence on the bronchoscopic lung volume reduction therapies and important aspects regarding optimal patient selection.

Identification of damage associated molecular patterns and extracellular matrix proteins as major constituents of the surface proteome of lung implantable silicone/nitinol devices

Lung implantable devices have been widely adopted as mechanical interventions for a wide variety of pulmonary pathologies. Despite successful initial treatment, long-term efficacy can often be impacted by fibrotic or granulation tissue formation at the implant sites. This study aimed to explore the lung-device interface by identifying the adhered proteome on lung devices explanted from patients with severe emphysema. In this study, scanning electron microscopy is used to visualize the adhesion of cells and proteins to silicone and nitinol surfaces of explanted endobronchial valves. By applying high-resolution mass-spectrometry, the surface proteome of eight explanted valves is characterized, identifying 263 unique protein species to be mutually adsorbed on the valves. This subset is subjected to gene enrichment analysis, matched with known databases and further validated using immunohistochemistry. Enrichment analyses reveal dominant clusters of functionally-related ontology terms associated with coagulation, pattern recognition receptor signaling, immune responses, cytoskeleton organization, cell adhesion and migration. Matching results show that extracellular matrix proteins and damage-associated molecular patterns are cardinal in the formation of the surface proteome. This is the first study investigating the composition of the adhered proteome on explanted lung devices, setting the groundwork for hypothesis generation and further exploration. STATEMENT OF SIGNIFICANCE: This is the first study investigating the composition of the adhered proteome on explanted lung devices. Lung implantable devices have been widely adopted as mechanical interventions for pulmonary pathologies. Despite successful initial treatment, long-term efficacy can often be impacted by fibrotic or granulation tissue formation around the implant sites. We identified the adhered proteome on explanted lung devices using several techniques. We identified 263 unique protein species to be mutually adsorbed on explanted lung devices. Pathway analyses revealed that these proteins are associated with coagulation, pattern recognition receptor signaling, immune responses, cytoskeleton organization, cell adhesion and migration. Furthermore, we identified that especially extracellular matrix proteins and damage-associated molecular patterns were cardinal in the formation of the surface proteome.

Crosslink bio-adhesives for bronchoscopic lung volume reduction: current status and future direction

Several bronchoscopic lung volume reduction (BLVR) treatments have been developed to reduce hyperinflation in emphysema patients. Lung bio-adhesives are among the most promising new BLVR treatment options, as they potentially provide a permanent solution for emphysematous patients after only a single application. To date, bio-adhesives have mainly been used as haemostats and tissue sealants, while their application in permanently contracting and sealing hyperinflated lung tissue has recently been identified as a novel and enticing opportunity. However, a major drawback of the current adhesive technology is the induction of severe inflammatory responses and adverse events upon administration. In our review, we distinguish between and discuss various natural, semi-synthetic and synthetic tissue haemostats and sealants that have been used for pulmonary applications such as sealing air/fluid leaks. Furthermore, we present an overview of the different materials including AeriSeal and autologous blood that have been used to achieve lung volume reduction and discuss their respective advantages and drawbacks. In conclusion, we describe the key biological (therapeutic benefit and biocompatibility) and biomechanical (degradability, adhesive strength, stiffness, viscoelasticity, tunability and self-healing capacity) characteristics that are essential for an ideal lung bio-adhesive material with the potential to overcome the concerns related to current adhesives.

Radiofrequency therapy improves exercise capacity of mice with emphysema

Emphysema is a common phenotype of chronic obstructive pulmonary disease (COPD). Although resection of emphysematous tissue can improve lung mechanics, it is invasive and fraught with adverse effects. Meanwhile, radiofrequency (RF) treatment is an extracorporeal method that leads to tissue destruction and remodeling, resulting in “volume reduction” and overall improvement in lung compliance of emphysematous lungs. Whether these changes lead to improved exercise tolerance is unknown. Here, we investigated the effectiveness of RF treatment to improve the exercise capacity of mice with emphysema. Fifty-two mice (7 weeks of age) were used in this experiment. A bilateral emphysema model was created by intratracheally instilling porcine pancreatic elastase (PPE) (1.5U/100 g body weight). RF treatment (0.5 W/ g body weight) was administered extracorporeally 14 days later and mice were sacrificed after another 21 days. The exercise capacity of mice was measured using a treadmill. Treadmill runs were performed just before PPE instillation (baseline), before RF treatment and before sacrifice. Following sacrifice, lung compliance and mean linear intercept (Lm) were measured and fibrosis was assessed using a modified Ashcroft score. There were 3 experimental groups: controls (instilled with saline, n = 12), emphysema (instilled with porcine pancreatic elastase, PPE, n = 11) and emphysema + treatment (instilled with PPE and given RF, n = 9). At endpoint, the maximum velocity of the emphysema + treatment group was significantly higher than that of the emphysema group, indicating improved exercise tolerance (86.29% of baseline vs 61.69% of baseline, p = 0.01). Histological analysis revealed a significant reduction in emphysema as denoted by Lm between the two groups (median 29.60 µm vs 35.68 µm, p = 0.03). The emphysema + treatment group also demonstrated a higher prevalence of lung fibrosis (≧Grade 3) compared with the emphysema group (11.7% vs 5.4%, p < 0.01). No severe adverse events from RF were observed. RF treatment improved the exercise capacity of mice with emphysema. These data highlight the therapeutic potential of RF treatment in improving the functional status of patients with COPD.

Airway granulation response to lung-implantable medical devices: a concise overview

Increasing numbers of endoscopically implantable devices are implanted in the airways, such as airway stents, one-way valves and coils, to treat both malignant and benign diseases. They significantly improve patient outcomes, but their long-term effectiveness and sustainability is hampered by the reaction of the formation of granulation tissue. Factors including procedural-related tissue injury; micro-organism presence; device-related factors, such as the material, design and sizing in relation to the airway; and patient-related factors, including genetic susceptibility, comorbidities and medication use, might all effect the severity of the tissue response and the subsequent degree of granulation tissue formation. However, research into the underlying mechanism and risk factors is scarce and therefore our knowledge is limited. Joint efforts from the scientific community, both pre-clinical and clinical, are needed to gain a deeper understanding and eventually improve the long-term treatment effectiveness of lung-implantable devices.

Medical implantable devices are increasingly used in pulmonary medicine. Complications related to the tissue–device interaction are often present, but our knowledge of the underlying processes is limited.https://bit.ly/2RdWVkG

An adjusted and time-saving method to measure collateral ventilation with Chartis

Introduction

Bronchoscopic lung volume reduction with endobronchial valves is an important treatment option in selected patients with severe emphysema and absence of collateral ventilation in the treatment target lobe. The Chartis system provides an important physiological assessment of the presence or absence of collateral ventilation. We aimed to evaluate a new feature and determine whether low flow during a Chartis measurement is predictive for the absence of collateral ventilation, and whether this allows for a procedure to be shortened by earlier terminating the Chartis measurement. This is measured with the “volume trend for the previous 20 s” (VT20).

Methods

We retrospectively evaluated 249 Chartis assessments of patients scheduled for bronchoscopic lung volume reduction procedures. The VT20 was calculated, and several thresholds were compared between patients with collateral ventilation (CV positive) and without collateral ventilation (CV negative).

Results

100% of the CV negative patients reached a threshold of VT20 ≤6 mL, whereas all CV positive patients reached a VT20 ≥7 mL. The median “time saved” between VT20=6 mL and end of assessment was 60 s (range 5–354 s).

Conclusion

The threshold of VT20 ≤6 mL is a reliable method to exclude the presence of collateral ventilation when air flow rates are low and can therefore reduce bronchoscopic lung volume procedure times.

The volume trend for the previous 20 s (VT20) is an adjusted method of the Chartis measurement. This feature helps to interpret the Chartis measurement more easily and it effectively shortens the Chartis assessment time, especially in cases with low flow.https://bit.ly/3wlClxv

Biodegradable stent placement for airway kinking after bronchoscopic lung volume reduction treatment

Symptomatic airway kinking after bronchoscopic lung volume reduction with endobronchial valves is rare. Due to the development of the desired lobar atelectasis, the position of the airways of the non-treated lobe changes and this might lead to invalidating symptoms. We present a case of a patient with symptomatic airway kinking after treatment with endobronchial valves, who was successfully treated with a single placement of a biodegradable stent. Placement of a biodegradable stent can be considered in symptomatic patients with airway kinking.

Lung volume reduction in real clinical practice

Pragmatic studies and capturing routine care clinical data in registration databases are important to further guide and optimise treatments in the future https://bit.ly/3el1lh7.

Expert Statement: Pneumothorax Associated with One-Way Valve Therapy for Emphysema: 2020 Update

For selected patients with advanced emphysema, bronchoscopic lung volume reduction with one-way valves can lead to clinically relevant improvements of airflow obstruction, hyperinflation, exercise capacity, and quality of life. The most common complication of this procedure is pneumothorax with a prevalence of up to ±34% of the treated patients. Patients who develop a pneumothorax also experience meaningful clinical benefits once the pneumothorax is resolved. Timely resolution of a post-valve treatment pneumothorax requires skilled and adequate pneumothorax management. This expert panel statement is an updated recommendation of the 2014 statement developed to help guide pneumothorax management after valve placement. Additionally, mechanisms for pneumothorax development, risk assessment, prevention of pneumothorax, and outcomes after pneumothorax are addressed. This recommendation is based on a combination of the current scientific literature and expert opinion, which was obtained through a modified Delphi method.

Revision Bronchoscopy After Endobronchial Valve Treatment for Emphysema: Indications, Findings and Outcomes

Background

Endobronchial valve (EBV) treatment is an effective treatment for patients with severe emphysema. Revision bronchoscopies after endobronchial valve treatment can be essential to prolong the effect of treatment or address long-term complications.

Purpose

To evaluate the indications, endoscopic findings and outcomes of revision bronchoscopies and investigate if any predictors for granulation tissue formation, after EBV treatment, can be identified.

Patients and Methods

Patients who underwent EBV treatment between 2016 and 2019 in our hospital, as routine care, were included. If a patient underwent a revision bronchoscopy, data regarding revision bronchoscopies, including indication, finding, intervention and pulmonary function testing (PFT) after revision bronchoscopy were analysed.

Results

One hundred seventy-nine patients were included of which 41% required at least one revision bronchoscopy. In 43% of the revision bronchoscopy patients, the indication was loss of initial treatment effect. In 53% of the revision bronchoscopy patients, granulation tissue was found to be the underlying cause. Valve replacement(s) were performed in 51% of the revision bronchoscopy cases. Permanent valve removal was required in 13% of all patients. Overall, revision bronchoscopies led to improvements in PFT outcomes for patients experiencing no or a loss of initial treatment effect. No clinically relevant predictors for granulation tissue formation were identified.

Conclusion

Performing a revision bronchoscopy after EBV treatment is a useful procedure leading to an improved treatment effect in most patients. Granulation tissue formation, causing valve dysfunction, is the most common cause of longer term problems.

Endobronchial Valves for the Treatment of Advanced Emphysema

Bronchoscopic lung volume reduction with one-way endobronchial valves is a guideline treatment option for patients with advanced emphysema that is supported by extensive scientific data. Patients limited by severe hyperinflation, with a suitable emphysema treatment target lobe and with absence of collateral ventilation, are the responders to this treatment. Detailed patient selection, a professional treatment performance, and dedicated follow up of the valve treatment, including management of complications, are key ingredients to success. This treatment does not stand alone; it especially requires extensive knowledge of COPD for which the most appropriate treatment is discussed in a multidisciplinary approach. We discuss the endobronchial valve treatment for emphysema and provide a guideline for patient selection, treatment guidance, and practice tools, based on our own experience and literature.