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

Developing Interventions for Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is an incurable, progressive respiratory disease that may have a significant negative impact on the morbidity and mortality of affected patients. A substantial portion of the world's population is affected by COPD, and despite optimal medical management with medications, supplemental oxygen, and pulmonary rehabilitation, many patients are left debilitated because of this disease. Bronchoscopic treatment modalities offer a less-invasive method for the treatment of refractory COPD compared to surgical interventions and have expanded the potential therapeutic options for these patients. Bronchoscopic lung volume reduction is aimed at decreasing the hyperinflation and air trapping that occur in emphysema, and the most studied and successful intervention is endobronchial valve placement. Endobronchial coils, polymeric sealants, and thermal ablation are other researched alternatives. Additional interventional procedures are being investigated for the treatment of the mucus hypersecretion and cough that are associated with the chronic bronchitis phenotype of COPD and include targeted lung denervation, metered dose spray cryotherapy, deobstruction balloon, and bronchial rheoplasty. This review summarizes the most recent evidence pertaining to available therapies for the management of COPD, including chronic bronchitis, with a particular focus on bronchoscopic interventions.

Bronchoscopic Lung Volume Reduction: A Review

Bronchoscopic lung volume reduction (BLVR) is an established treatment modality for the management of advanced chronic obstructive pulmonary disease complicated by severe emphysema and hyperinflation refractory to other therapies. BLVR aims to reduce hyperinflation and residual volume, thereby improving pulmonary function, symptom control, and quality of life. Multiple distinct devices and technologies, including endobronchial coils, thermal vapor ablation, bio-lung volume reduction, and airway bypass stenting, have been developed to achieve lung volume reduction with varying degrees of accessibility and evidence. The most promising BLVR treatment modality to date has been the placement of one-way endobronchial valves (EBVs), with more than 25,000 cases performed worldwide. Identifying symptomatic patients who would benefit from BLVR is challenging and can be time and resource intensive, and candidacy may be limited by physiologic parameters. Additional new technologies may be able to improve the identification and evaluation of candidates as well as increase the portion of evaluated patients who ultimately qualify for BLVR. In this review, we aim to provide historical context to BLVR, summarize the available evidence regarding its use, discuss potential complications, and provide readers with a clear guide to patient selection and referral for BLVR, with a focus on EBV placement. In addition, we will highlight potential future directions for the field.

Winning the Tour de France with endobronchial valve therapy without pulmonary rehabilitation

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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.

Treatable traits in advanced emphysema patients eligible for bronchoscopic lung volume reduction with endobronchial valves

INTRODUCTION

Patients with advanced emphysema eligible for bronchoscopic lung volume reduction (BLVR) using endobronchial valves (EBV) are characterized by severe static lung hyperinflation, which can be considered a treatable trait. Other treatable traits (TTs), which are assumed to be present in this highly selected patient group, have not been studied in detail nor how they may affect health-related quality of life (HRQL).

AIMS

We aimed to evaluate a spectrum of TTs in COPD patients eligible for EBV treatment and their association with HRQL.

METHODS

The SoLVE study (NCT03474471) was a prospective multicenter randomized controlled trial to examine the impact of pulmonary rehabilitation in COPD patients receiving EBV. The presence/absence of 16 TTs was based on pre-defined thresholds. HRQL was assessed with the St. George's Respiratory Questionnaire (SGRQ). Subjects were stratified into two groups, using the median split method, into higher or lower SGRQ total score. Logistic regression assessed the odds ratio (OR) of having a higher SGRQ total score per TT.

RESULTS

Ninety-seven subjects were included, the mean number of TTs per patient was 8.1 ± 2.5. Low physical activity (95%), poor exercise capacity (94%) and severe fatigue (75%) were the most prevalent TTs. The sum of TTs present in a subject was associated with the SGRQ total score (r = 0.53; p < 0.001). Severe fatigue, depression, and anxiety were predictors of having a higher SGRQ total score.

CONCLUSIONS

A high prevalence and co-occurrence of multiple TTs were identified in emphysema patients eligible for EBV. Patients with a higher number of TTs were more likely to have worse HRQL.

Bronchoscopic lung volume reduction in emphysema: a review

PURPOSE OF REVIEW

Chronic obstructive pulmonary disease (COPD) poses a substantial burden on the healthcare system and is currently considered the sixth leading cause of death in the United States. Emphysema, as evidenced by severe air-trapping in patients with COPD, leads to significant dyspnea and morbidity. Lung volume reduction via surgery or minimally invasive endobronchial interventions are currently available, which improve lung function and quality of life.

RECENT FINDINGS

Newer studies have noted a survival benefit in patients post bronchoscopic lung volume reduction vs. those subjected to standard of care. The presence of collateral ventilation is one of the most common impeding factors to placing endobronchial valves, and if placed, these patients might not achieve lobar atelectasis; however, there are newer modalities that are now available for patients with collateral ventilation which we have described.

SUMMARY

Combining standard of care treatment that includes smoking cessation, bronchodilators, preventive care including vaccinations, pulmonary rehabilitation, and endobronchial treatment using various interventions in decreasing hyperinflation improves quality of life and may improve survival and hence significantly reduce the burden of COPD on healthcare.

By deflating the lungs pulmonologists help the cardiologists. A literature review

In this review, we present the effects of lung hyperinflation on the cardiovascular system (CVS) and the beneficial outcomes of different deflation treatment modalities. We discuss the effects of long-acting bronchodilator drugs, medical and surgical lung volume reduction on the performance of the CVS. Although there is a small number of studies investigating lung deflation and the CVS, the short-term improvement in heart function was clearly demonstrated. However, more studies, with longer duration, are needed to verify these significant beneficial effects of deflation of the lungs on the CVS. Dynamic hyperinflation during exercise could be a research model to investigate further the effects of lung hyperinflation and/or deflation on the CVS.

Surgical and Interventional Approaches in COPD

Many patients suffer from complaints of dyspnea, cough, and sputum production, clinical symptoms that hallmark the structural abnormalities that are present in patients with COPD. Although pharmacologic and non-pharmacologic medical therapies help reduce these symptoms, many of these symptoms, especially dyspnea, remain unchecked and contribute to the burden of disease in patients with COPD. Over the last 3 decades, several surgical and interventional treatments delivered via a bronchoscopic approach have been developed to complement medical therapies and show promise to improve patient outcomes. Surgical and interventional treatments target structural abnormalities of the airway and lung parenchyma that can be identified with a combination of imaging and physiological testing, factors that are key to select patients most likely to benefit from these treatments. This paper reviews surgical and bronchoscopic interventional treatment options for patients with emphysema and airways disorders.

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.