Bronchoscopic Lung Volume Reduction for End-Stage Emphysema

A preclinical animal study to evaluate the operability and safety of domestic one-way endobronchial valves

Purpose

To evaluate the operability and safety of bronchoscopic domestic one-way endobronchial valves (EBV) on animals.

Methods

Nine pigs were randomly assigned (2:1) to receive domestic one-way EBV (the experimental group, n = 6) and Zephyr® EBV (the control group, n = 3). Routine blood tests, arterial blood gases, and CT scans of the lungs were performed 1 day pre-procedure in addition to 1 week and 1 month post-procedure to assess changes in blood markers and lung volumes. At 1 month post-procedure, the animals were sacrificed, followed by removal of all valves via bronchoscopy. Pathological examinations of critical organs were subsequently performed.

Results

A total of 15 valves were placed in the experimental group and 6 valves were placed in the control group, without serious complications. Routine blood tests and arterial blood gas examinations at 1 day pre-procedure, 1 week post-procedure, and 1 month post-procedure did not differ significantly in both groups. No EBV displacement was noted under bronchoscopy, and the valve was smoothly removable by bronchoscope at 1 month post-procedure. At 1 week post-procedure, varying degrees of target lung lobe volume reduction were observed on lung CT in both groups. Lung volume reduction was achieved at 1 month post-procedure in both groups, without significant statistical difference. Although 3 cases in the experimental group and 1 case in the control group developed varying degrees of pneumonia, the inflammatory response did not increase over time during the experimental period. Pathological examination revealed no significant abnormal changes in the critical organs for both groups.

Conclusion

Our results demonstrate that domestic EBV is safe and reliable for endobronchial application in general-grade laboratory white pigs. The safety of domestic EBV is similar to that of Zephyr® EBV, with good ease of use and operability. This kind of domestic EBV can meet the safety evaluation requirements for animal testing.

Bronchoscopic lung volume reduction by instillation of fibrinogen and thrombin in COPD patients with homogenous emphysema

BACKGROUND

The new endobronchial therapy called biological lung volume reduction (BioLVR) involves using a rapid polymerizing sealant to block off the most emphysematous portions of the lungs. The primary mechanism of action is resorption atelectasis, which is then followed by inflammation and remodeling of the airspace. The remodeling process will result in the formation of scars, leading to the contraction of the lung tissue. As a result, a decrease in functional lung volume is anticipated for a period of 6-8 weeks.

OBJECTIVE

Assessing the safety and effectiveness of bronchoscopic installation of (fibrinogen and thrombin) in COPD patients with homogeneous emphysema in terms of radiological, physiological, and quality of life outcomes.

METHODS

Between December 2017 and December 2019, 40 COPD patients with homogeneous emphysema were studied using a fiber optic bronchoscope while they were awake but sedated. Tanta University Hospitals' chest medicine department collaborated with the diagnostic radiology department of the Faculty of Medicine.

RESULTS

All the following parameters were reduced from their initial values: HRCT volumetry, RV/TLC, mMRC dyspnea scale, CAT score, 6MWT, FEV1, and the FEV1/FVC ratio at the first, third, and sixth months from the beginning (p = 0.001). One individual (0.025%) had pneumonia, whereas three individuals had COPD (0.075%). Using fibrin glue produced locally, biological lung volume reduction (Bio LVR) may be an effective treatment for advanced homogenous emphysema.

CONCLUSION

By using locally prepared fibrin glue the biologic lung volume reduction (Bio LVR) may be a convenient method to treat advanced homogenous emphysema.

Application of 3D computed tomography in emphysematous parenchyma patients scheduled for bronchoscopic lung volume reduction

Bronchoscopic lung volume reduction (BLVR) is a feasible, safe, effective and minimally invasive technique to significantly improve the quality of life of advanced severe chronic obstructive pulmonary disease (COPD). In this study, three-dimensional computed tomography (3D-CT) automatic analysis software combined with pulmonary function test (PFT) was used to retrospectively evaluate the postoperative efficacy of BLVR patients. The purpose is to evaluate the improvement of lung function of local lung tissue after operation, maximize the benefits of patients, and facilitate BLVR in the treatment of patients with advanced COPD. All the reported cases of advanced COPD patients treated with BLVR with one-way valve were collected and analysed from 2017 to 2020. Three-dimensional-CT image analysis software system was used to analyse the distribution of low-density areas <950 Hounsfield units in both lungs pre- and post- BLVR. Meanwhile, all patients performed standard PFT pre- and post-operation for retrospective analysis. We reported six patients that underwent unilateral BLVR with 1 to 3 valves according to the range of emphysema. All patients showed a median increase in forced expiratory volume in 1 second (FEV1) of 34%, compared with baseline values. Hyperinflation was reduced by 16.6% (range, 4.9%-47.2%). The volumetric measurements showed a significant reduction in the treated lobe volume among these patients. Meanwhile, the targeted lobe volume changes were inversely correlated with change in FEV1/FEV1% in patients with heterogeneous emphysematous. We confirm that 3D-CT analysis can quantify the changes of lung volume, ventilation and perfusion, to accurately evaluate the distribution and improvement of emphysema and rely less on the observer.

Pediatric interventional bronchoscopy: from early limitations to achievable opportunities

PURPOSE OF REVIEW

The rapid evolution of bronchoscopy equipment and technologies, from the introduction of the 1.1 mm flexible cryoprobe to the use of navigational and robotic bronchoscopy, has afforded unprecedented opportunities for pediatric advanced diagnostic and interventional bronchoscopy. While there is growing interest among pediatric pulmonologists to incorporate these new techniques into their practice, the current pediatric landscape is characterized by few practicing interventional bronchoscopists, scant published literature, and no formal training programs.

RECENT FINDINGS

While the majority of the published literature consists of case reports and small case series, the increased application of new techniques is starting to yield larger and more structured studies that will be able to provide more objective commentary on the proposed indications, safety, and efficacy of such techniques in the pediatric population.

SUMMARY

For many decades, progress in pediatric advanced diagnostic and interventional bronchoscopy was slow and deliberate, limited by the lack of appropriately sized equipment and experienced interventional bronchoscopists. The current opportunities afforded require equal, or perhaps even more, vigilance as pediatric pulmonologists employ new equipment and technologies and define new practices and standards of care. Importantly, this review is meant to serve as a general conspectus of pediatric advanced diagnostic and interventional bronchoscopy and not a consensus guideline for the performance of advanced or even routine bronchoscopy in the pediatric population. For technical standards of pediatric bronchoscopy, refer to existing guidelines [1,2] .

Multi-site, Multi-domain Airway Tree Modeling

Open international challenges are becoming the de facto standard for assessing computer vision and image analysis algorithms. In recent years, new methods have extended the reach of pulmonary airway segmentation that is closer to the limit of image resolution. Since EXACT'09 pulmonary airway segmentation, limited effort has been directed to the quantitative comparison of newly emerged algorithms driven by the maturity of deep learning based approaches and extensive clinical efforts for resolving finer details of distal airways for early intervention of pulmonary diseases. Thus far, public annotated datasets are extremely limited, hindering the development of data-driven methods and detailed performance evaluation of new algorithms. To provide a benchmark for the medical imaging community, we organized the Multi-site, Multi-domain Airway Tree Modeling (ATM'22), which was held as an official challenge event during the MICCAI 2022 conference. ATM'22 provides large-scale CT scans with detailed pulmonary airway annotation, including 500 CT scans (300 for training, 50 for validation, and 150 for testing). The dataset was collected from different sites and it further included a portion of noisy COVID-19 CTs with ground-glass opacity and consolidation. Twenty-three teams participated in the entire phase of the challenge and the algorithms for the top ten teams are reviewed in this paper. Both quantitative and qualitative results revealed that deep learning models embedded with the topological continuity enhancement achieved superior performance in general. ATM'22 challenge holds as an open-call design, the training data and the gold standard evaluation are available upon successful registration via its homepage (https://atm22.grand-challenge.org/).

A Novel Robotic Bronchoscope System for Navigation and Biopsy of Pulmonary Lesions

Transbronchial biopsy sampling, as a minimally invasive method with relatively low risk, has been proved to be a promising treatment in the field of respiratory surgery. Although several robotic bronchoscopes have been developed, it remains a great challenge to balance size and flexibility, while integrating multisensors to realize navigation during complex airway networks. This paper proposes a novel robotic bronchoscope system composed by end effector with relatively small size, relevant actuation unit, and navigation system with path planning and surgical guidance capability. The main part of the end effector is machined by bidirectional groove on a nickel-titanium tube, which can realize bending, rotation, and translation 3 degrees of freedom. A prototype of the proposed robotic bronchoscope system is designed and fabricated, and its performance is tested through several experiments to verify the stiffness, flexibility, and navigation performance. The results show that the proposed system is with good environment adaptiveness, and it can become a promising biopsy method through natural cavity of the human body.

Vision-Kinematics Interaction for Robotic-Assisted Bronchoscopy Navigation

Endobronchial intervention is increasingly used as a minimally invasive means for the treatment of pulmonary diseases. In order to acquire the position of bronchoscopy, vision-based localization approaches are clinically preferable but are sensitive to visual variations. The static nature of pre-operative planning makes mapping of intraoperative anatomical features challenging for learning-based methods using visual features alone. In this work, we propose a robust navigation framework based on Vision Kinematic Interaction (VKI) for monocular bronchoscopic videos. To address visual-imbalance between the virtual and real views of bronchoscopy images, a Visual Similarity Network (VSN) is proposed to extract domain-invariant features to represent the lumen structure from endoscopic views, as well as domain-specific features to characterize the surface texture and visual artefacts. To improve the robustness of online estimation of camera pose, we also introduce a Kinematic Refinement Network (KRN) that allows progressive refinement of camera pose estimation based on network prediction and robot control signals. The accuracy of camera localization is validated on phantom and porcine lung datasets from a robotically controlled endobronchial intervention system, with both quantitative and qualitative results demonstrating the performance of the techniques. Results show that the features extracted by the proposed method can preserve the structural information of small airways in the presence of large visual variations along with the much-improved camera localization accuracy. The absolute trajectory errors (ATE) on phantom data and porcine data are 8.01 mm and 8.62 mm respectively.

How Do Mechanics Guide Fibroblast Activity? Complex Disruptions during Emphysema Shape Cellular Responses and Limit Research

The emphysema death toll has steadily risen over recent decades, causing the disease to become the third most common cause of death worldwide in 2019. Emphysema is currently incurable and could be due to a genetic condition (Alpha-1 antitrypsin deficiency) or exposure to pollutants/irritants, such as cigarette smoke or poorly ventilated cooking fires. Despite the growing burden of emphysema, the mechanisms behind emphysematous pathogenesis and progression are not fully understood by the scientific literature. A key aspect of emphysematous progression is the destruction of the lung parenchyma extracellular matrix (ECM), causing a drastic shift in the mechanical properties of the lung (known as mechanobiology). The mechanical properties of the lung such as the stiffness of the parenchyma (measured as the elastic modulus) and the stretch forces required for inhalation and exhalation are both reduced in emphysema. Fibroblasts function to maintain the structural and mechanical integrity of the lung parenchyma, yet, in the context of emphysema, these fibroblasts appear incapable of repairing the ECM, allowing emphysema to progress. This relationship between the disturbances in the mechanical cues experienced by an emphysematous lung and fibroblast behaviour is constantly overlooked and consequently understudied, thus warranting further research. Interestingly, the failure of current research models to integrate the altered mechanical environment of an emphysematous lung may be limiting our understanding of emphysematous pathogenesis and progression, potentially disrupting the development of novel treatments. This review will focus on the significance of emphysematous lung mechanobiology to fibroblast activity and current research limitations by examining: (1) the impact of mechanical cues on fibroblast activity and the cell cycle, (2) the potential role of mechanical cues in the diminished activity of emphysematous fibroblasts and, finally, (3) the limitations of current emphysematous lung research models and treatments as a result of the overlooked emphysematous mechanical environment.

Pediatric advanced diagnostic and interventional bronchoscopy

The indications and utility of flexible bronchoscopy have expanded over the past few decades with major innovations in design and development of new tools for endobronchial interventions and image-guided tissue sampling techniques. This review highlights the application of advanced diagnostic bronchoscopy (including endobronchial ultrasound and CT navigational techniques), cryotherapy and the use of one-way endobronchial valves for persistent air leak in the pediatric setting.

Pre-operative optimisation for chronic obstructive pulmonary disease: a narrative review

Chronic obstructive pulmonary disease is a condition commonly present in older people undergoing surgery and confers an increased risk of postoperative complications and mortality. Although predominantly a respiratory disease, it frequently has extra-pulmonary manifestations and typically occurs in the context of other long-term conditions. Patients experience a range of symptoms that affect their quality of life, functional ability and clinical outcomes. In this review, we discuss the evidence for techniques to optimise the care of people with chronic obstructive pulmonary disease in the peri-operative period, and address potential new interventions to improve outcomes. The article centres on pulmonary rehabilitation, widely available for the treatment of stable chronic obstructive pulmonary disease, but less often used in a peri-operative setting. Current evidence is largely at high risk of bias, however. Before surgery it is important to ensure that what have been called the 'five fundamentals' of chronic obstructive pulmonary disease treatment are achieved: smoking cessation; pulmonary rehabilitation; vaccination; self-management; and identification and optimisation of co-morbidities. Pharmacological treatment should also be optimised, and some patients may benefit from lung volume reduction surgery. Psychological and behavioural factors are important, but are currently poorly understood in the peri-operative period. Considerations of the risk and benefits of delaying surgery to ensure the recommended measures are delivered depends on patient characteristics and the nature and urgency of the planned intervention.

Clinical Utility of Quantitative CT Analysis for Fissure Completeness in Bronchoscopic Lung Volume Reduction: Comparison between CT and Chartis™

Objective

The absence of collateral ventilation (CV) is crucial for effective bronchoscopic lung volume reduction (BLVR) with an endobronchial valve. Here, we assessed whether CT can predict the Chartis™ results.

Materials and Methods

This study included 69 patients (mean age: 70.9 ± 6.6 years; 66 [95.7%] males) who had undergone CT to assess BLVR eligibility. The Chartis™ system (Pulmonox Inc.) was used to check CV. Experienced thoracic radiologists independently determined the completeness of fissures on volumetric CT images.

Results

The comparison between the visual and quantitative analyses revealed that 5% defect criterion showed good agreement. The Chartis™ assessment was performed for 129 lobes; 11 (19.6%) of 56 lobes with complete fissures on CT showed positive CV, while this rate was significantly higher (40 of 49 lobes, i.e., 81.6%) for lobes with incomplete fissures. The size of the fissure defect did not affect the rate of CV. Of the patients who underwent BLVR, 22 of 24 patients (91.7%) with complete fissures and three of four patients with incomplete fissures (75%) achieved target lobe volume reduction (TLVR).

Conclusion

The quantitative analysis of fissure shows that incomplete fissures increased the probability of CV on Chartis™, while the defect size did not affect the overall rates. TLVR could be achieved even in some patients with relatively large fissure defect, if they showed negative CV on Chartis™.

Bronchoscopic device intervention in chronic obstructive pulmonary disease

PURPOSE OF REVIEW

Chronic obstructive pulmonary disease is a heterogeneous syndrome associated with varying degrees of parenchymal emphysema and airway inflammation resulting in decreased expiratory flow, lung hyperinflation, and symptoms leading to decreased exercise tolerance and quality of life. Impairment in lung function and quality of life persists following guideline-based medical therapy, thus surgical and minimally invasive bronchoscopic approaches were developed to address this unmet need. We offer a narrative review of the available technologies.

RECENT FINDINGS

Although lung volume reduction surgery has been shown to improve survival in appropriately selected patients, it is infrequently performed. Less invasive bronchoscopic procedures have thus been explored including endobronchial valves, coils, lung sealant, thermal vapor, and other airway approaches. Selection criteria including severity of physiologic and radiographic impairment, degree of lung hyperinflation, presence of intact fissures, type of symptoms, and presence of comorbidities are critical in selecting appropriate candidates.

SUMMARY

Recent advances in minimally invasive approaches to lung volume reduction have offered alternatives to surgical approaches. Two endobronchial valve devices are Food and Drug Administration approved for clinical use, and investigations into alternative bronchoscopic therapies to treat both emphysema and chronic bronchitis have been performed or are currently underway. Notably, each of these treatments requires unique selection criteria and thus a personalized approach to treatment.

CELEB trial: Comparative Effectiveness of Lung volume reduction surgery for Emphysema and Bronchoscopic lung volume reduction with valve placement: a protocol for a randomised controlled trial

INTRODUCTION

Although lung volume reduction surgery and bronchoscopic lung volume reduction with endobronchial valves have both been shown to improve lung function, exercise capacity and quality of life in appropriately selected patients with emphysema, there are no direct comparison data between the two procedures to inform clinical decision-making.

METHODS AND ANALYSIS

We describe the protocol of the CELEB study, a randomised controlled trial which will compare outcomes at 1 year between the two procedures, using a composite disease severity measure, the iBODE score, which includes body mass index, airflow obstruction, dyspnoeaand exercise capacity (incremental shuttle walk test).

ETHICS AND DISSEMINATION

Ethical approval to conduct the study has been obtained from the Fulham Research Ethics Committee, London (16/LO/0286). The outcome of this trial will provide information to guide treatment choices in this population and will be presented at national and international meetings and published in peer-reviewed journals. We will also disseminate the main results to all participants in a letter.

TRIAL REGISTRATION NUMBER

ISRCTN19684749; Pre-results.

The safety and efficacy of endobronchialvalve therapy in patients with advanced heterogeneous emphysema versus standard medical care: A meta-analysis

BACKGROUND

Endobronchial valves had been utilized for many years to treat patients with advanced emphysema, despite unfavorable results. In this meta-analysis, we aimed to assess the efficacy and safety of the use of endobronchial valves in patients with heterogeneous advanced emphysema.

METHODS

We performed systematic database searches to identify clinical trials that met all our inclusion criteria. Direct-comparison and mixed-treatment-comparison (MTC) meta-analyses were conducted to estimate the mean difference or odds ratio of outcomes. Each outcome was analyzed with Review Manager 5 statistical software.

RESULTS

Eight prospective clinical trials assessing this therapy were retrieved, with a total of 744 patients. Outcomes, including the forced expiratory volume in 1 second (FEV1), 6-minute walk test (6MWT), and St. George's Respiratory Questionnaire (SGRQ), were analyzed, and the odds ratio of reported complications related to endobronchial valve therapy was calculated. Significant improvement in the mean difference of FEV1 (5.61 [4.42, 6.80]), 6MWT (25.75 [12.30, 39.20]), and SGRQ (-10.96 [-13.88, -8.05]) was observed after endobronchial valve treatment. Moreover, the rate of adverse events related to endobronchial valves was low.

CONCLUSIONS

Endobronchial valve treatment offers benefits in terms of lung function and quality of life. Endobronchial valve treatment is feasible and safe for patients with advanced heterogeneous emphysema, especially those with no evidence of collateral ventilation.

Bronchoscopic lung volume reduction with endobronchial valves for heterogeneous emphysema: long-term results

Background

Bronchoscopic lung volume reduction (BLVR) with implant of one-way endobronchial valves (EBV) is a feasible treatment for management of heterogeneous emphysema (HE) with clinical benefits in the early follow-up. We aimed to evaluate the long-terms results and safety of this procedure in a consecutive series of patients with HE.

Methods

It was a retrospective single center study including all consecutive patients with HE undergoing EBV treatment and completing at least 5 years of long-term follow-up. Patients were splitted into Collapse and No-Collapse Group if a lobar collapse or not were obtained after valves implant. The difference of functional data and quality of life (QoL) before and after the procedure (measured at 3, 6, 9, 12 months from the valve implantation, and then annually up to a maximum of 5 years) were statistically evaluated to show the long-term benefits of the procedure (primary endpoint). Yet, morbidity, mortality and survival rates were also recorded to show the safe of the treatment (secondary endpoint).

Results

Thirty-three patients were included in the study. Of these, three patients underwent a bilateral treatment. Collapse Group patients (n=27) presented a significant improvement in FEV1% (+17%; P=0.001); in FVC% (+18%; P=0.002); in RV% (-39%; P=0.003); in 6MWT (P=0.001) and in SGRQ (P=0.001) in the early 12 months of follow-up and no significant decline was seen later. Conversely, No-Collapse Group (n=9) did not have significant benefits. No major complications and death related to the procedure were observed. The 1-,2-,3-,4- and 5-year survival rates were 100%, 90%, 78%, 71% and 71%, respectively. Collapse Group had a better survival than No-Collapse Group (45 vs. 24 months; P=0.001).

Conclusions

Our study confirmed that the lobar collapse is the key success of EBV treatment and the early improvements of respiratory function could be maintained up to five years from the valves implant.

Pop-Up MEMS One-Way Endobronchial Valve for Treatment of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of morbidity in aging populations worldwide. One of the most debilitating effects of COPD is hyperinflation, which restricts the function of healthier portions of the lung, diaphragm, and heart. Bronchoscopic lung volume reduction (BLVR) is a minimally invasive technique to reduce hyperinflation, consisting of one-way valves inserted bronchoscopically that slowly drain the diseased lobe of its accumulated air. Presented here is a novel redesign of current BLVR devices using pop-up microelectromechanical systems (MEMS) manufacturing to create microscale check valves. These operate more reliably than current polymer valves and allow tunable airflow to accommodate widely varying patient physiologies. Analysis and ex vivo testing of the redesigned valve predicted the valve should outlast current valves with a lifetime of well over 8 yr and showed airflow controllability within desired physiological ranges of up to 1.2 SLM. The valve resists backflow twice as well as the current standard valves while permitting comparable forward flow.

Comparison of distinctive models for calculating an interlobar emphysema heterogeneity index in patients prior to endoscopic lung volume reduction

Background

The degree of interlobar emphysema heterogeneity is thought to play an important role in the outcome of endoscopic lung volume reduction (ELVR) therapy of patients with advanced COPD. There are multiple ways one could possibly define interlobar emphysema heterogeneity, and there is no standardized definition.

Purpose

The aim of this study was to derive a formula for calculating an interlobar emphysema heterogeneity index (HI) when evaluating a patient for ELVR. Furthermore, an attempt was made to identify a threshold for relevant interlobar emphysema heterogeneity with regard to ELVR.

Patients and methods

We retrospectively analyzed 50 patients who had undergone technically successful ELVR with placement of one-way valves at our institution and had received lung function tests and computed tomography scans before and after treatment. Predictive accuracy of the different methods for HI calculation was assessed with receiver-operating characteristic curve analysis, assuming a minimum difference in forced expiratory volume in 1 second of 100 mL to indicate a clinically important change.

Results

The HI defined as emphysema score of the targeted lobe (TL) minus emphysema score of the ipsilateral nontargeted lobe disregarding the middle lobe yielded the best predicative accuracy (AUC =0.73, P=0.008). The HI defined as emphysema score of the TL minus emphysema score of the lung without the TL showed a similarly good predictive accuracy (AUC =0.72, P=0.009). Subgroup analysis suggests that the impact of interlobar emphysema heterogeneity is of greater importance in patients with upper lobe predominant emphysema than in patients with lower lobe predominant emphysema.

Conclusion

This study reveals the most appropriate ways of calculating an interlobar emphysema heterogeneity with regard to ELVR.

Bronchoscopic lung volume reduction procedures for chronic obstructive pulmonary disease

BACKGROUND

In the recent years, a variety of bronchoscopic lung volume reduction (BLVR) procedures have emerged that may provide a treatment option to participants suffering from moderate to severe chronic obstructive pulmonary disease (COPD).

OBJECTIVES

To assess the effects of BLVR on the short- and long-term health outcomes in participants with moderate to severe COPD and determine the effectiveness and cost-effectiveness of each individual technique.

SEARCH METHODS

Studies were identified from the Cochrane Airways Group Specialised Register (CAGR) and by handsearching of respiratory journals and meeting abstracts. All searches are current until 07 December 2016.

SELECTION CRITERIA

We included randomized controlled trials (RCTs). We included studies reported as full text, those published as abstract only and unpublished data, if available.

DATA COLLECTION AND ANALYSIS

Two independent review authors assessed studies for inclusion and extracted data. Where possible, data from more than one study were combined in a meta-analysis using RevMan 5 software.

MAIN RESULTS

AeriSealOne RCT of 95 participants found that AeriSeal compared to control led to a significant median improvement in forced expiratory volume in one second (FEV₁) (18.9%, interquartile range (IQR) -0.7% to 41.9% versus 1.3%, IQR -8.2% to 12.9%), and higher quality of life, as measured by the St Georges Respiratory Questionnaire (SGRQ) (-12 units, IQR -22 units to -5 units, versus -3 units, IQR -5 units to 1 units), P = 0.043 and P = 0.0072 respectively. Although there was no significant difference in mortality (Odds Ratio (OR) 2.90, 95% CI 0.14 to 62.15), adverse events were more common for participants treated with AeriSeal (OR 3.71, 95% CI 1.34 to 10.24). The quality of evidence found in this prematurely terminated study was rated low to moderate. Airway bypass stentsTreatment with airway bypass stents compared to control did not lead to significant between-group changes in FEV₁ (0.95%, 95% CI -0.16% to 2.06%) or SGRQ scores (-2.00 units, 95% CI -5.58 units to 1.58 units), as found by one study comprising 315 participants. There was no significant difference in mortality (OR 0.76, 95% CI 0.21 to 2.77), nor were there significant differences in adverse events (OR 1.33, 95% CI 0.65 to 2.73) between the two groups. The quality of evidence was rated moderate to high. Endobronchial coilsThree studies comprising 461 participants showed that treatment with endobronchial coils compared to control led to a significant between-group mean difference in FEV₁ (10.88%, 95% CI 5.20% to 16.55%) and SGRQ (-9.14 units, 95% CI -11.59 units to -6.70 units). There were no significant differences in mortality (OR 1.49, 95% CI 0.67 to 3.29), but adverse events were significantly more common for participants treated with coils (OR 2.14, 95% CI 1.41 to 3.23). The quality of evidence ranged from low to high. Endobronchial valvesFive studies comprising 703 participants found that endobronchial valves versus control led to significant improvements in FEV₁ (standardized mean difference (SMD) 0.48, 95% CI 0.32 to 0.64) and scores on the SGRQ (-7.29 units, 95% CI -11.12 units to -3.45 units). There were no significant differences in mortality between the two groups (OR 1.07, 95% CI 0.47 to 2.43) but adverse events were more common in the endobronchial valve group (OR 5.85, 95% CI 2.16 to 15.84). Participant selection plays an important role as absence of collateral ventilation was associated with superior clinically significant improvements in health outcomes. The quality of evidence ranged from low to high. Intrabronchial valvesIn the comparison of partial bilateral placement of intrabronchial valves to control, one trial favoured control in FEV₁ (-2.11% versus 0.04%, P = 0.001) and one trial found no difference between the groups (0.9 L versus 0.87 L, P = 0.065). There were no significant differences in SGRQ scores (MD 2.64 units, 95% CI -0.28 units to 5.56 units) or mortality rates (OR 4.95, 95% CI 0.85 to 28.94), but adverse events were more frequent (OR 3.41, 95% CI 1.48 to 7.84) in participants treated with intrabronchial valves. The lack of functional benefits may be explained by the procedural strategy used, as another study (22 participants) compared unilateral versus partial bilateral placement, finding significant improvements in FEV₁ and SGRQ when using the unilateral approach. The quality of evidence ranged between moderate to high. Vapour ablationOne study of 69 participants found significant mean between-group differences in FEV₁ (14.70%, 95% CI 7.98% to 21.42%) and SGRQ (-9.70 units, 95% CI -15.62 units to -3.78 units), favouring vapour ablation over control. There was no significant between-group difference in mortality (OR 2.82, 95% CI 0.13 to 61.06), but vapour ablation led to significantly more adverse events (OR 3.86, 95% CI 1.00 to 14.97). The quality of evidence ranged from low to moderate.

AUTHORS' CONCLUSIONS

Results for selected BLVR procedures indicate they can provide significant and clinically meaningful short-term (up to one year) improvements in health outcomes, but this was at the expense of increased adverse events. The currently available evidence is not sufficient to assess the effect of BLVR procedures on mortality. These findings are limited by the lack of long-term follow-up data, limited availability of cost-effectiveness data, significant heterogeneity in results, presence of skew and high CIs, and the open-label character of a number of the studies.

Predicting Structure-Function Relations and Survival following Surgical and Bronchoscopic Lung Volume Reduction Treatment of Emphysema

Lung volume reduction surgery (LVRS) and bronchoscopic lung volume reduction (bLVR) are palliative treatments aimed at reducing hyperinflation in advanced emphysema. Previous work has evaluated functional improvements and survival advantage for these techniques, although their effects on the micromechanical environment in the lung have yet to be determined. Here, we introduce a computational model to simulate a force-based destruction of elastic networks representing emphysema progression, which we use to track the response to lung volume reduction via LVRS and bLVR. We find that (1) LVRS efficacy can be predicted based on pre-surgical network structure; (2) macroscopic functional improvements following bLVR are related to microscopic changes in mechanical force heterogeneity; and (3) both techniques improve aspects of survival and quality of life influenced by lung compliance, albeit while accelerating disease progression. Our model predictions yield unique insights into the microscopic origins underlying emphysema progression before and after lung volume reduction.

Surgical and, more recently, bronchoscopic lung volume reduction is the only available treatments for patients with advanced stage emphysema. Several large-scale, clinical studies have outlined appropriate selection criteria based on patient outcomes; however, the underlying mechanisms determining disease progression and response to these treatments are not well-understood. To answer this question, we have developed a network model of the lung to compare immediate and long-term response to each treatment. This approach allows us to directly study macroscopic changes in function related to microscopic changes in the local structural and mechanical environment. In addition, it facilitates direct comparisons between surgical and bronchoscopic lung volume reduction given identical initial conditions, which is not feasible in a clinical study. We propose here a mechanism suggesting that lung volume reduction efficacy is intimately linked to changes in microscopic force heterogeneity within the lung. Such an understanding of the mechanisms driving emphysema has the potential to greatly improve current therapies for this condition through more rationalized, patient-specific treatment strategies.

Bronchoscopic Lung Volume Reduction with Endobronchial Valves in Low-FEV1 Patients

BACKGROUND

Bronchoscopic lung volume reduction (BLVR) with valves has been shown to improve lung function, exercise capacity, and quality of life in patients with emphysema, but only few patients with forced expiratory volume in 1 s (FEV1) ≤20% predicted have been included in former studies. Although the procedure can be performed safely, pneumothorax is a frequent complication, which can be critical for these very severely diseased patients.

OBJECTIVES

The aim of the study was to assess the safety of BLVR in patients with a very advanced stage of emphysema, as indicated by FEV1 ≤20% predicted.

PATIENTS AND METHODS

Patients in whom BLVR was performed between January 2013 and August 2015 were included in this analysis if their baseline predicted FEV1 was ≤20%. BLVR, performed only if collateral ventilation was absent, achieved complete occlusion of the target lobe. All patients were closely monitored and were not discharged before the fourth day after BLVR.

RESULTS

Twenty patients with FEV1 ≤20% predicted were included in the analysis. Lung volume reduction was achieved in 65% of the cases. Pneumothorax occurred in 4 cases (20%). No patient died. Lung function and exercise tolerance improved after 1 and 3 months, respectively.

CONCLUSIONS

BLVR with valves can be safely performed in patients with FEV1 ≤20% predicted when close postprocedural monitoring is provided. Improvement in lung function and exercise capacity can be achieved.

Status of and prospects for bronchoscopic lung volume reduction for patients with severe emphysema

Bronchoscopic lung volume reduction (BLVR) is a minimally invasive treatment for severe emphysema, providing treatment options for patients who are unable to undergo lung volume reduction surgery (LVRS) or lung transplantation. Current BLVR techniques include bronchoscopic volume reduction with valve implants, use of a lung volume reduction coil (LVRC), bronchoscopic thermal vapor ablation (BTVA), biological lung volume reduction (BioLVR), and use of airway bypass stents (ABS). To date, several randomized controlled trials of these bronchoscopic therapies have been conducted in patients with emphysema, and bronchoscopic volume reduction with valve implants remains the best approach thus far. Recent studies indicate that BLVR may be of great value in improving lung function, exercise capacity, and quality of life and that BLVR has the potential to replace conventional surgery for patients with severe emphysema. Optimal patient selection and the proper selection of the BLVR technique in accordance with patient characteristics are crucial to the success of BLVR. More multicenter, prospective, randomized controlled trials need to be conducted in the future to optimize the current selection strategy and evaluate the safety, efficiency, and long-term benefit of BLVR techniques.

Video-Assisted Thoracoscopic Surgery for Treatment of Chronic Obstructive Pulmonary Disease

The aim of this study is to evaluate the safety and efficacy of lung volume reduction surgery (LVRS) by video-assisted thoracoscopic surgery (VATS) in the treatment of chronic obstructive pulmonary disease (COPD). A total of 90 patients with COPD from 2002 to 2012 were enrolled into our study, comprising 22 who underwent conventional thoracotomies and 68 VATS. Pulmonary function testings, arterial blood gases analysis, and quality of life between these two groups were compared. VATS was found to be superior to the conventional thoracotomy in terms of length of hospital stay, intraoperative blood loss, intubation time, volume of chest tube drainage, and postoperative pain assessment (P < 0.05). However, significant differences in pulmonary function testings, arterial blood gases analysis, 6-min walking distance (6-MWD), and postoperative quality of life between the two groups were not found (P > 0.05). LVRS by VATS is a safe and reliable surgical approach for the treatment of COPD, with less invasiveness and shorter hospital recovery time.

Fissure Integrity and Volume Reduction in Emphysema: A Retrospective Study

BACKGROUND

One-way endobronchial valves (EBVs) relieve symptoms of emphysema, particularly in patients without collateral ventilation between the target and adjacent lobes. Pretreatment knowledge of fissure integrity could serve as an aid in indicating EBV interventions.

OBJECTIVE

This study aimed to investigate the relationship between software-measured lung fissure integrity and clinically relevant lung volume reduction (≥350 ml) in emphysema patients treated with one-way EBVs using a lobar exclusion strategy.

METHODS

Of 108 patients treated between March 2008 and July 2014, 38 had both baseline and follow-up computed tomography (CT) scans acquired following a specific protocol for quantitative CT analysis and were included in the study (total of 39 treatments, two lungs treated in 1 patient). Outcome measures were fissure integrity measured on baseline CT scans, difference between pre- and postoperative lung volume (considering the lowest measured postoperative volume), and correlation between fissure integrity and volume change.

RESULTS

Fissure integrity ≥75% correlated with volume reduction ≥350 ml (Spearman coefficient: -0.65; p < 0.01). The mean and median volume reductions were 1,223.96 ± 907.5 ml and 663 ml, respectively, for lungs with fissure integrity ≥75% (n = 31). The accuracy of fissure integrity ≥75% in predicting a volume reduction was 87.2%. The positive predictive value of fissure integrity ≥75% to predict a volume reduction ≥350 ml was 83.9%, and it was 70% for fissure integrity 75-90% and 90.5% for fissure integrity >90%.

CONCLUSIONS

A target lobe volume reduction using EBVs is possible with lung fissure integrity ≥75%. For patients with fissure integrity between 75 and 90%, a further evaluation of interlobar ventilation should be performed. A clinically relevant volume reduction following treatment with EBVs is likely with any level of fissure integrity >90%.

Update on Nonsurgical Lung Volume Reduction Procedures

There has been a surge of interest in endoscopic lung volume reduction (ELVR) strategies for advanced COPD. Valve implants, coil implants, biological LVR (BioLVR), bronchial thermal vapour ablation, and airway stents are used to induce lung deflation with the ultimate goal of improving respiratory mechanics and chronic dyspnea. Patients presenting with severe air trapping (e.g., inspiratory capacity/total lung capacity (TLC) < 25%, residual volume > 225% predicted) and thoracic hyperinflation (TLC > 150% predicted) have the greatest potential to derive benefit from ELVR procedures. Pre-LVRS or ELVR assessment should ideally include cardiological evaluation, high resolution CT scan, ventilation and perfusion scintigraphy, full pulmonary function tests, and cardiopulmonary exercise testing. ELVR procedures are currently available in selected Canadian research centers as part of ethically approved clinical trials. If a decision is made to offer an ELVR procedure, one-way valves are the first option in the presence of complete lobar exclusion and no significant collateral ventilation. When the fissure is not complete, when collateral ventilation is evident in heterogeneous emphysema or when emphysema is homogeneous, coil implants or BioLVR (in that order) are the next logical alternatives.

Non-pharmacological treatments for COPD

Chronic obstructive pulmonary disease (COPD) affects roughly 10% of the global population and is growing in prevalence annually. COPD is characterized by progressive non-reversible narrowing of airways mainly due to cigarette smoking. Therapeutic interventions aimed at altering this progressive disease course can largely be grouped into pharmacological or non-pharmacological therapies. The focus of this paper is on the non-pharmacological aspects of COPD management, reviewing the current literature to provide an evidence-based management approach. Non-pharmacological therapies reviewed in this article include the implementation of comprehensive care models utilizing a coordinated multidisciplinary team, tele-monitoring and patient-centred approach to optimize COPD care and improve compliance. Preventing progression of COPD via smoking cessation remains of paramount importance, and newer therapeutic options including electronic cigarettes show promise in small studies as cessation aids. COPD has systemic manifestations that can be ameliorated with the enrollment in pulmonary rehabilitation programmes, which focus on exercise endurance to improve dyspnoea and quality of life. Advanced therapeutics for COPD includes lung volume reduction surgery for a pre-specified cohort and minimally invasive bronchoscopic valves that in recent reviews show promise. Lastly, patients on maximal COPD therapy with progressive disease can be referred for lung transplantation; however, this often requires a highly selected and motivated patient and care team. Survival rates for lung transplantation are improving; thus, this procedure remains a viable option as more expertise and experience are gained.

Time course and predictive factors for lung volume reduction following stereotactic ablative radiotherapy (SABR) of lung tumors

Background

Stereotactic ablative volume reduction (SAVR) is a potential alternative to lung-volume reduction surgery in patients with severe emphysema and excessive surgical risk. Having previously observed a dose-volume response for localized lobar volume reduction after stereotactic ablative radiotherapy (SABR) for lung tumors, we investigated the time course and factors associated with volume reduction.

Methods

We retrospectively identified 70 eligible patients receiving lung tumor SABR during 2007-2013. We correlated lobar volume reduction (relative to total, bilateral lung volume [TLV]) with volume receiving high biologically effective doses (V_XXBED3) and other pre-treatment factors in all patients, and measured the time course of volume changes on 3-month interval CT scans in patients with large V_60BED3 (n = 21, V_60BED3 ≥4.1 % TLV).

Results

Median CT follow-up was 15 months. Median volume reduction of treated lobes was 4.5 % of TLV (range 0.01–13.0 %), or ~9 % of ipsilateral lung volume (ILV); median expansion of non-target adjacent lobes was 2.2 % TLV (−4.6–9.9 %; ~4 % ILV). Treated lobe volume reduction was significantly greater with larger V_XXBED3 (XX = 20–100 Gy, R² = 0.52–0.55, p < 0.0001) and smaller with lower pre-treatment FEV1% (R² = 0.11, p = 0.005) in a multivariable linear model. Maximum volume reduction was reached by ~12 months and persisted.

Conclusions

We identified a multivariable model for lobar volume reduction after SABR incorporating dose-volume and pre-treatment FEV1% and characterized its time course.

Electronic supplementary material

The online version of this article (doi:10.1186/s13014-016-0616-8) contains supplementary material, which is available to authorized users.

An update on the efficacy of endobronchial valve therapy in the management of hyperinflation in patients with chronic obstructive pulmonary disease

Lung volume reduction surgery has been shown to be effective in patients with heterogeneous emphysema, but is also associated with a relatively high perioperative morbidity and mortality. Accordingly, several novel and potentially less invasive methods for bronchoscopic lung volume reduction have been developed. Endobronchial valve (EBV) therapy is one such therapeutic approach in patients with advanced emphysema. It has been the most widely studied technique over the past years and represents an effective treatment option for patients with severe heterogeneous upper- or lower-lobe-predominant emphysema. The choice of EBV therapy largely depends on the distribution of emphysema and the presence or absence of interlobar collateral ventilation. Adequate patient selection and technical success of valve implantation with the intention of lobar exclusion are predictive factors for positive outcomes. This review attempts to highlight the milestones in the development of bronchoscopic lung volume reduction with one-way valve implantation over the past few years.

Modifying Post-Operative Medical Care after EBV Implant May Reduce Pneumothorax Incidence

Objective

Endoscopic lung volume reduction (ELVR) with valves has been shown to improve COPD patients with severe emphysema. However, a major complication is pneumothoraces, occurring typically soon after valve implantation, with severe consequences if not managed promptly. Based on the knowledge that strain activity is related to a higher risk of pneumothoraces, we asked whether modifying post-operative medical care with the inclusion of strict short-term limitation of strain activity is associated with a lower incidence of pneumothorax.

Methods

Seventy-two (72) emphysematous patients without collateral ventilation were treated with bronchial valves and included in the study. Thirty-two (32) patients received standard post-implantation medical management (Standard Medical Care (SMC)), and 40 patients received a modified medical care that included an additional bed rest for 48 hours and cough suppression, as needed (Modified Medical Care (MMC)).

Results

The baseline characteristics were similar for the two groups, except there were more males in the SMC cohort. Overall, ten pneumothoraces occurred up to four days after ELVR, eight pneumothoraces in the SMC, and only two in the MMC cohorts (p=0.02). Complicated pneumothoraces and pneumothoraces after upper lobe treatment were significantly lower in MMC (p=0.02). Major clinical outcomes showed no significant differences between the two cohorts.

Conclusions

In conclusion, modifying post-operative medical care to include bed rest for 48 hours after ELVR and cough suppression, if needed, might reduce the incidence of pneumothoraces. Prospective randomized studies with larger numbers of well-matched patients are needed to confirm the data.

Effects of bronchoscopic lung volume reduction using transbronchial infusion of autologous blood and thrombin in patients with severe chronic obstructive pulmonary disease

BACKGROUND

Existing medical treatments have limitations in the management of very severe chronic obstructive pulmonary disease (COPD).

METHODS

We performed bronchoscopic lung volume reduction (BLVR) using transbronchial infusion of autologous blood and thrombin (BLVR with blood) in three patients with very severe COPD whose dyspnea could not be relieved by maximum medical management. Two patients underwent BLVR with blood in the left and right lungs at intervals of a half-year or a year, and one patient underwent this procedure in only the right lung. We assessed the changes in pulmonary function, exercise capacity and quality of life before and after BLVR with blood in a total of five procedures.

RESULTS

The subjects were 58- to 74-year-old males. Their forced expiratory volume in one second (FEV1) percent predicted ranged from 14.8% to 23.4%. BLVR with blood achieved significant improvements as follows (values before → after the procedure, mean ± standard deviation): FEV1 0.45r the L → 0.76r the L (P=0.004), inspiratory capacity 1.50cityo L → 2.05±.05c L (P=0.015), 3-minute walk test 46.8nuteo m → 89.6±34.5 m (P=0.004). Lung function peaked several months after BLVR with blood and returned to nearly the baseline level in 6 months, but exercise capacity was better than that at baseline for at least 12 months. St. George's Respiratory Questionnaire (SGRQ), measured in two patients before and 12 months after the procedure, showed remarkable improvements (-15.6 and -11.9 units).

CONCLUSIONS

BLVR with blood is an effective palliative treatment for very severe COPD.

Efficacy and safety of endobronchial valves for advanced emphysema: a meta analysis

OBJECTIVE

A meta-analysis was undertaken to evaluate the efficacy and safety of bronchoscopic lung volume reduction with endobronchial valves (EBV) for advanced emphysema.

METHODS

A systematic search was performed from PubMed, EMBASE, CNKI, Cochrane Library database. Randomized control clinical trials on treatment of emphysema for 3-12 months with the EBV compared with standard medications and sham EBV were reviewed. Inclusion criteria were applied to select patients with advanced emphysema treated with EBV. The primary outcome was the percentage of the forced expiratory volume in the first second (FEV1%). Secondary outcomes included St George's Respiratory Questionnaire (SGRQ) score, the distance of the 6-minute walk (6MWD) test, the Modified Medical Research Council (MMRC) dyspnoea score, cycle ergometry workload, and the rate of the six major complications at 3 or 12 months. Fixed- or random-effects models were used and weighted mean differences (WMD), relative risks (RR) and 95% confidence intervals (CI) were calculated.

RESULTS

Three trials (565 patients) were considered in the meta-analysis. EBV patients yielded greater increases in FEV1% than standard medications (WMD =6.71; 95% CI, 3.31 to 10.10; P=0.0001), EBV patients also demonstrated a significant change for SGRQ score (WMD =-3.64; 95% CI, -5.93 to -1.34; P=0.002), MMRC dyspnoea score (WMD =-0.26; 95% CI, -0.44 to -0.08; P=0.004), and cycle ergometry workload (WMD =4.18; 95% CI, 2.14 to 6.22; P<0.0001). A similar level was evident for 6MWD (WMD =11.66; 95% CI, -3.31 to 26.64; P=0.13). EBV may increase the rate of hemoptysis (RR =5.15; 95% CI, 1.16 to 22.86; P=0.03), but didn't increase the adverse events including mortality, respiratory failure, empyema, pneumonia, pneumothrax. The overall rates for complications compared EBV with standard medications and sham EBV was not significant (RR =2.03; 95% CI, 0.98 to 4.21; P=0.06).

CONCLUSIONS

EBV lung volume reduction for advanced emphysema showed superior efficacy and a good safety and tolerability compared with standard medications and sham EBV, further more randomized controlled trial (RCT) studies are needed to pay more attention to the long-term efficacy and safety of bronchoscopic lung volume reduction with EBV in advanced emphysema.

Radiologic manifestations of bronchoscopic lung volume reduction in severe chronic obstructive pulmonary disease

OBJECTIVE. Bronchoscopic lung volume reduction promises to become an effective treatment option in severe chronic obstructive pulmonary disease. Several techniques are currently being investigated, including implantation of devices into the lung and instillation of hot water vapor or polymer. This article reviews the spectrum of radiologic manifestations on chest radiography and CT that occur after the intervention. CONCLUSION. Familiarity with the intended effects and adverse events will aid the radiologist in supporting bronchoscopic lung volume reduction.

Effectiveness of bronchoscopic lung volume reduction using unilateral endobronchial valve: a systematic review and meta-analysis

BACKGROUND

Bronchoscopic lung volume reduction (BLVR) can be suggested as an alternative for surgical lung volume reduction surgery for severe emphysema patients. This article intends to evaluate by systematic review the safety and effectiveness of BLVR using a one-way endobronchial valve.

METHODS

A systematic search of electronic databases, including MEDLINE, EMBASE, and the Cochrane Library, as well as eight domestic databases up to December 2013, was performed. Two reviewers independently screened all references according to selection criteria. The Scottish Intercollegiate Guidelines Network criterion was used to assess quality of literature. Data from randomized controlled trials were combined and meta-analysis was performed.

RESULTS

This review included 15 studies. Forced expiratory volume in 1 second (FEV1) improved in the intervention group compared with the control group (mean difference [MD]=6.71, 95% confidence interval [CI]: 3.31-10.11). Six-minute walking distance (MD=15.66, 95% CI: 1.69-29.64) and cycle workload (MD=4.43, 95% CI: 1.80-7.07) also improved. In addition, St George's Respiratory Questionnaire score decreased (MD=4.29, 95% CI: -6.87 to -1.71) in the intervention group. In a subgroup analysis of patients with complete fissure, the FEV1 change from baseline was higher in the BLVR group than in the control group for both 6 months (MD=15.28, P<0.001) and 12 months (MD=17.65, P<0.001), whereas for patients with incomplete fissure, FEV1 and 6-minute walking distance showed no change. One-year follow-up randomized controlled trials reported deaths, although the cause of death was not related to BLVR. Respiratory failure and pneumothorax incidence rates were relatively higher in the BLVR group, but the difference was not significant.

CONCLUSION

BLVR may be an effective and safe procedure for the treatment of severe COPD patients with emphysema, based on existing studies.

Effect of endobronchial valve therapy on pulmonary perfusion and ventilation distribution

INTRODUCTION

Endoscopic lung volume reduction (ELVR) is an emerging therapy for emphysematous COPD. However, any resulting changes in lung perfusion and ventilation remain undetermined. Here, we report ELVR-mediated adaptations in lung perfusion and ventilation, as investigated by means of pulmonary scintigraphy.

METHODS

In this observational study, we enrolled 26 patients (64.9 ± 9.4 yrs, 57.7% male) with COPD heterogeneous emphysema undergoing ELVR with endobronchial valves (Zephyr, Pulmonx, Inc.). Mean baseline FEV1 and RV were 32.9% and 253.8% predicted, respectively. Lung scintigraphy was conducted prior to ELVR and eight weeks thereafter. Analyses of perfusion and ventilation shifts were performed and complemented by correlation analyses between paired zones.

RESULTS

After ELVR, target zone perfusion showed a mean relative reduction of 43.32% (p<0.001), which was associated with a significant decrease in target zone ventilation (p<0.001). Perfusion of the contralateral untreated zone and of the contralateral total lung exhibited significant increases post-ELVR (p = 0.002 and p = 0.005, respectively); both correlated significantly with the corresponding target zone perfusion adaptations. Likewise, changes in target zone ventilation correlated significantly with ventilatory changes in the contralateral untreated zone and the total contralateral lung (Pearson's r: -0.42, p = 0.04 and Pearson's r: -0.42, p = 0.03, respectively). These effects were observed in case of clinical responsiveness to ELVR, as assessed by changes in the six-minute walk test distance.

DISCUSSION

ELVR induces a relevant decrease in perfusion and ventilation of the treated zone with compensatory perfusional and ventilatory redistribution to the contralateral lung, primarily to the non-concordant, contralateral zone.

Endobronchial valves in treatment of persistent air leaks: a systematic review of clinical evidence

Background

Persistent air leak is one of the most common complications of lung diseases and pulmonary resections. Prolonged hospitalization, increased morbidity, and increased overall treatment costs arise from persistent air leaks. The use of endobronchial valves (EBVs) in the management of air leaks is an important alternative, especially for patients who are not candidates for surgical treatment.

Material/Methods

We retrieved the included studies by performing a systematic search in PubMed and Scopus databases. The references of the included studies were also hand-searched.

Results

We retrieved 25 case reports and 3 case series from our literature search. The most common cause of persisting air leaks was spontaneous secondary pneumothorax (12/39, 31%). The left upper lobe (13/39, 33%) and right upper lobe (14/39, 36%) were the most frequent locations of air leaks. Most air leaks treated with EBVs ceased in less than 24 h. Three recurrences of air leak were reported and 2 cases of EBV migration were described. No deaths were reported in correlation with EBVs.

Conclusions

EBVs are a minimally invasive therapeutical option that may be suitable for the treatment of persistent air leaks regardless of the initial cause, especially in high-risk patients. Nevertheless, studies with better methodological quality are essential to standardize this technique and to provide more evidence on EBV safety issues.

Endoscopic lung volume reduction with endobronchial valves in patients with severe emphysema and established pulmonary hypertension

BACKGROUND

One of the most common forms of pulmonary hypertension (PH) is that associated with chronic obstructive pulmonary disease (COPD). So far, patients with severe emphysema and established PH have been excluded from endoscopic lung volume reduction (ELVR) therapy due to the risk of right heart decompensation.

OBJECTIVE

The aim of this pilot study was to evaluate the feasibility and efficacy of ELVR using one-way endobronchial valves (EBV) in this specific group of patients.

METHODS

We prospectively included 6 patients with COPD, severe heterogeneous emphysema, and established PH who underwent right heart catheterization and clinical assessments before and 90 days after ELVR with unilateral EBV placement.

RESULTS

This study was not powered to measure any statistical differences in endpoints. Ninety days after ELVR, the symptoms, lung function, and hemodynamics improved in 5 out of 6 patients (1 patient normalized and 1 slightly worsened). The mean hemodynamics improved from baseline to 90 days after ELVR as follows: mean pulmonary artery pressure, -2.5 ± 3.5 mm Hg; pulmonary arterial wedge pressure, -4.3 ± 8.3 mm Hg; cardiac index, +0.3 ± 0.6 l/min/m(2), and 6-min walk distance, +59 ± 99 m. ELVR was performed without PH-related complications in all patients.

CONCLUSION

To our knowledge, this is the first prospective, single-center pilot study to evaluate the feasibility and efficacy of ELVR in patients with established PH. ELVR was feasible and resulted in an improvement of clinical and hemodynamic parameters in 5 out of 6 patients. These results have to be further confirmed in larger-scale controlled studies.

Endobronchial valves in the treatment of persistent air leak, an alternative to surgery

INTRODUCTION

Persistent air leak is frustrating for both patients and physicians, above all leaks with a high risk of surgery. Insertion of endobronchial valves could be an alternative to surgery. The aim of this study is to describe our experience in these valves and analyse their efficacy in a series of patients with persistent air leaks.

MATERIAL AND METHODS

The valves are inserted by means of flexible bronchoscopy under conscious sedation and local anesthesia. A preliminary bronchoscopy identifies the air leak by bronchial occlusion using a balloon catheter. A successful outcome is defined as complete disappearance of the leak following removal of the chest drain, without the need for further surgery.

RESULTS

From November 2010 to December 2013, 8 patients with persistent air leaks were treated with endobronchial valves. The number of valves used ranged from 1 to 4 (median 2), with a median duration of air leak prior to placement of 15.5 days. There were no complications and the resolution of the leak was complete in 6 of 8 patients (75%). The median duration of drainage after insertion of the valves was 13 days and the median time to removal of 52.5 days.

CONCLUSIONS

Insertion of endobronchial valves is a safe and effective method for treating persistent air leaks, and a valid alternative to surgery.

Advanced therapies for COPD-What's on the horizon? Progress in lung volume reduction and lung transplantation

Advanced chronic obstructive pulmonary disease (COPD) is a significant cause of morbidity. Treatment options beyond conventional medical therapies are limited to a minority of patients. Lung volume reduction surgery (LVRS) although effective in selected subgroups of patients is not commonly undertaken. Morbidity associated with the procedure has contributed to this low utilisation. In response to this, less invasive bronchoscopic lung volume techniques are being developed to attempt to mitigate some of the risks and costs associated with surgery. Of these, endobronchial valve therapy is the most comprehensively studied although the presence of collateral ventilation in a significant proportion of patients has compromised its widespread utility. Bronchial thermal vapour ablation and lung volume reduction (LVR) coils are not dependent on collateral ventilation. These techniques have shown promise in early clinical trials; ongoing work will establish whether they have a role in the management of advanced COPD. Lung transplantation, although effective in selected patients for palliation of symptoms and improving survival, is limited by donor organ availability and economic constraint. Reconditioning marginal organs previously declined for transplantation with ex vivo lung perfusion (EVLP) is one potential strategy in improving the utilisation of donor organs. By increasing the donor pool, it is hoped lung transplantation might be more accessible for patients with advanced COPD into the future.

Bronchoscopic interventions for severe COPD

Chronic obstructive pulmonary disease (COPD) causes severe handicap among smokers. Most patients have to remain under continuous oxygen therapy at home. Moreover, respiratory infections are very common among these patients and vaccination is obligatory against influenza. Emphysema and bronchiectasis are observed with computed tomography (CT) and in several situations these parenchymal damages are responsible for pneumothorax in one case and pseudomonas aeroginosa infection. Novel mini-invasive techniques are used currently for emphysema treatments which are described extensively throughout our current work.

Endoscopic lung volume reduction. An American perspective

There are limited therapies for severe emphysema. Bronchoscopic treatments of emphysema were introduced to achieve the beneficial physiological changes seen in surgical lung volume reduction; however, at the present time these treatments are mostly aimed at improving quality of life and functional status in patients with emphysema. At this time, none of these minimally invasive approaches have been approved in the United States for treatment of emphysema; however, several novel interventions have demonstrated potential in early-phase clinical trials. We performed a systematic evaluation of the relevant medical literature and present herein an evidence-based review of bronchoscopic treatments for emphysema, with a focus on the current status of this technology in the United States as compared with Europe.

Bronchoscopic interventions for chronic obstructive pulmonary disease

Over the past decade, several non-surgical and minimally invasive bronchoscopic lung volume reduction (BLVR) techniques have been developed to treat patients with severe chronic obstructive pulmonary disease (COPD). BLVR can be significantly efficacious, suitable for a broad cohort of patients, and associated with a solid safety profile at a reasonable expense. The introduction of BLVR is also expected to accelerate the further development of interventional pulmonology worldwide. Recently, results from clinical studies on BLVR techniques have been published, providing valuable information about the procedure's indications, contraindications, patient-selection criterion and outcomes. BLVR utilizing one-way endobronchial valves is gaining momentum as an accepted treatment in regular medical practice because of the identification of best responders. Patients with a heterogeneous emphysema distribution and without inter-lobar collateral ventilation show encouraging results. Furthermore, for patients with collateral ventilation, who are not considered candidates for valve treatment, and for patients with homogeneous emphysema, the introduction of lung volume reduction coil treatment is a promising solution. Moreover, with the development of newer treatment modalities, that is, biochemical sealant and thermal water vapor, the potential to treat emphysema irrespective of collateral flow, may be further increased. Nevertheless, patient selection for BLVR treatment will be crucial for the procedure's success and should be performed using a multidisciplinary team approach. Consequently, BLVR needs to be concentrated in high-volume centres that will offer better quality and experience with treatment challenges and adverse events. This review gives a general overview of BLVR from an expert and scientific perspective.