The lung volume reduction coil for the treatment of emphysema: a new therapy in development

The Effects of Endobronchial Coil Therapy on Right Ventricular Functions

Lung hyperinflation is an important therapeutic target in symptomatic emphysema patients. Endobronchial therapies that reduce end-expiratory lung volume are increasingly being used in advanced cases. However, there is paucity of data regarding the effects of these therapies on the heart functions. The aim of this study is to evaluate the right ventricular functions before and after the procedure in patients who underwent endobronchial coil therapy (EBCT).Patients who were between 18 and 80 years of age and scheduled for EBCT with GOLD 3-4 were enrolled in the study. Right heart functions were evaluated using MPI, TAS, TAPSE. Right atrium area and maximum velocity of tricuspid regurgitation were also noted.A total of 23 patients were enrolled in the study. 21 patients underwent bilateral intervention, while only 2 patients received unilateral treatment. There was an improvement in MPI (0.49 ± 0.15 vs 0.39 ± 0.11, p < 0.001) and TAS (11.6 (9 - 15) vs 13.2 (9.80 - 17.0), p = 0.001). Peak TRV (2.52 ± 0.6, 2.38 ± 0.6, p = 0.02) and PASP values were lower in the post-operative period (41.15 ± 5.94 vs 36.83 ± 8.01 p = 0.019).In this current study, we found improved echocardiographic RtV parameters in patients who received EBCT treatment.

A New-Designed Lung-Bending Device for Bronchoscopic Lung Volume Reduction of Severe Emphysema: A Feasibility Study in Pigs

BACKGROUND

Bronchoscopic therapies are less invasive alternatives of surgical lung volume reduction for severe emphysema. Bending of lung tissue by implanting metallic coils into bronchi is one of the procedures. A new-designed device with a similar rationale, Reverser, has been developed with some improvements.

OBJECTIVES

The aim of the study was to evaluate the safety and feasibility of the Reversers.

METHODS

Twelve healthy pigs were randomly divided into 3 groups (groups A, B, and C). The Reversers were implanted bronchoscopically into the selected airways using a proprietary delivery system. Physical examination, chest fluoroscopy, computed tomography (CT) scans, and bronchoscopic observations were performed before implantation and during the follow-up period. Necropsy was performed respectively at 1 month (group A), 3 months (group B), and 6 months (group C) after implantation.

RESULTS

A total of 47 Reversers were implanted successfully. The procedure was feasible and well tolerated by all pigs. No severe complications, such as pneumothorax, abscesses, and airway hemorrhage, were found. No unintended injuries or death occurred. Mild granulation and inflammation were observed in the airway wall. Opacities around Reversers were shown on CT scans in some pigs. In the pigs with opacities, histological evaluation revealed widened alveolar septa due to inflammatory cell infiltration in the vicinity of the Reversers. On the analysis of CT data, there was a trend for volume reduction of the treated lung at 1 and 3 months after treatment compared with baseline.

CONCLUSIONS

This study showed that Reversers were safe and feasible for bronchoscopic lung volume reduction in pigs.

Prediction of response to endobronchial coiling based on morphologic emphysema characterization of the lung lobe to be treated and the ipsilateral non-treated lobe as well as on functional computed tomography-data: correlation with clinical and pulmonary function

Background

To test if the emphysema type of the targeted lobe, ipsilateral non-targeted lobe, and lobes of the contralateral lung impact outcome of endobronchial lung volume reduction (ELVR) treatment, and to document lobar volume changes in treated and non-treated lung lobes.

Methods

Thirty patients (16 men, 14 women; median age, 66±6 years; range, 48-78 years) underwent chest-computed tomography (CT) before and after endobronchial coiling for lung volume reduction (LVR) at our institution between December 2011 and March 2016. Forty-five pulmonary lobes were coiled. We classified the treated lobes into homogenous or heterogeneous emphysema phenotype based on the distribution of voxels showing tissue attenuation of less than -950 HU. Clinical response was defined as an increase or consistency in the walking distance (6MWT) 6 months after LVR-therapy. Lung volume changes were compared for treated, ipsilateral, and contralateral lobes. Additionally, pulmonary function tests (PFT), chronic obstructive pulmonary disease (COPD) assessment test (CAT), and blood gas analysis were performed.

Results

Responder (19/30, 63.3%) showed a significant improvement of 6 MWT from 281.05 to 335.26 (P=0.001). Non-responder (11/30, 36.7%) showed a decrease in 6MWT from 308.18 to 255.45 (P=0.001). Responders showed a significant reduction in CAT test from 23.23 to 20.73 points (P=0.038) and pCO₂ from 42.94 to 40.31 (P=0.001), whereas non-responders showed an increase in pCO₂ (P=0.003; from 44.27 to 47.45). There were no significant changes in PFT-parameters. In responders, there was a significant volume reduction in treated lobes from 1,627.68 to 1,519.21 mL (P=0.009). In responders, treated lobes/non-treated ipsilateral lobes were homogenous (n=11/5) and heterogeneous (n=10/28). In non-responders, treated lobes/non-treated ipsilateral were homogenous (n=5/4) and heterogeneous (n=7/16). In responders and non-responders, the emphysema phenotype in treated, ipsilateral non-treated and even contralateral lobes (P=0.250) did not differ and or change significantly before and after therapy. Only the volume of treated lobes in responders changed significantly after coiling.

Conclusions

The emphysema-phenotype in the targeted and non-targeted ipsilateral lobe has no impact on the outcome of endobronchial coiling for LVR and also does not change significantly after treatment, whereas the volume of the treated lobe significantly decreases in responders.

Bronchoscopic treatment of emphysema: an update

Chronic obstructive pulmonary disease (COPD) is the major causes of disability and mortality. The efficacy of maximal medical treatment, although effective at the early stages of the disease, becomes limited when extensive alveolar destruction is the main cause of respiratory failure. At this stage of the disease more aggressive options, when feasible, should be considered. Lung transplantation and lung volume reduction surgery (LVRS) are currently available for a selected group of patients. Endoscopic alternatives to LVRS have progressively gained acceptance and are currently employed in patients with COPD. They promote lung deflation searching the same outcome as LVRS in terms of respiratory mechanics, ameliorating the distressing symptom of chronic dyspnea by decreasing the physiological dead space.

Endobronchial Coils for Endoscopic Lung Volume Reduction: Best Practice Recommendations from an Expert Panel

Endobronchial coils are an additional treatment option for lung volume reduction in patients with severe emphysema. Patient selection should be focused on patients with severe emphysema on optimal medical therapy and with evidence of severe hyperinflation. The technique is suitable in a broad range of patients with emphysema; however, patients with paraseptal emphysema, large focal (giant) bullae, significant co-morbidity and airway-predominant disease should be avoided. Treatment involves placing between 10 and 14 coils by bronchoscopy in the selected treatment lobe, with 2 lobes being treated sequentially. Lobe selection for treatment should be based on quantitative computed tomography, and the lobes with the greatest destruction should be targeted (excluding the right middle lobe). The treatment results in an improvement in pulmonary function, exercise performance and quality of life, particularly in patients with severe hyperinflation (residual volume > 200% predicted) and upper-lobe heterogeneous emphysema, but will also be of benefit in lower-lobe predominant and homogeneous emphysema. Finally, it has an acceptable safety profile, although special attention has to be paid to coil-associated opacity which is an inflammatory response that occurs in some patients treated with endobronchial coils.

The Safety and Feasibility of Re-treating Patients with Severe Emphysema with Endobronchial Coils: A Pilot Study

Severe emphysema patients who have been treated with endobronchial coils have been shown to initially benefit, but slowly decline in the years thereafter. Re-treating a patient with endobronchial coils could potentially lead to new improvements and may again reduce the rate of further decline. To our knowledge, until now, no results are published about patients who are re-treated. The primary aim of this study is to investigate the safety and feasibility of re-treating severe emphysema patients with endobronchial coils, using the PneumRx coil system. Furthermore, as secondary aim, we will evaluate the efficacy of re-treating these patients. Patients who at least 2 years ago were treated with endobronchial coils and responded clinically meaningful to this treatment were included in the study and re-treated. Safety was evaluated by the number of reported adverse events. Efficacy was evaluated 6 months after re-treatment, and measured by the change in quality of life, exercise capacity and pulmonary function testing. Eight patients were re-treated at a median of 1382 days (range 849-1545) after initial coil treatment with a median additional of 12 (10-15) coils per patient. During treatment, and until 6 months of follow-up, no unexpected adverse events occurred. Quality of life, exercise capacity and lung function did not change significantly 6 months after re-treatment. The results of this pilot study suggest that re-treating patients with endobronchial coils is feasible and safe. However, larger studies are needed to confirm these results and to investigate the efficacy and thus the clinical relevance.

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.

Lung volume reduction surgery for diffuse emphysema

BACKGROUND

Lung volume reduction surgery (LVRS) performed to treat patients with severe diffuse emphysema was reintroduced in the nineties. Lung volume reduction surgery aims to resect damaged emphysematous lung tissue, thereby increasing elastic properties of the lung. This treatment is hypothesised to improve long-term daily functioning and quality of life, although it may be costly and may be associated with risks of morbidity and mortality. Ten years have passed since the last version of this review was prepared, prompting us to perform an update.

OBJECTIVES

The objective of this review was to gather all available evidence from randomised controlled trials comparing the effectiveness of lung volume reduction surgery (LVRS) versus non-surgical standard therapy in improving health outcomes for patients with severe diffuse emphysema. Secondary objectives included determining which subgroup of patients benefit from LVRS and for which patients LVRS is contraindicated, to establish the postoperative complications of LVRS and its morbidity and mortality, to determine which surgical approaches for LVRS are most effective and to calculate the cost-effectiveness of LVRS.

SEARCH METHODS

We identified RCTs by using the Cochrane Airways Group Chronic Obstructive Pulmonary Disease (COPD) register, in addition to the online clinical trials registers. Searches are current to April 2016.

SELECTION CRITERIA

We included RCTs that studied the safety and efficacy of LVRS in participants with diffuse emphysema. We excluded studies that investigated giant or bullous emphysema.

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

We identified two new studies (89 participants) in this updated review. A total of 11 studies (1760 participants) met the entry criteria of the review, one of which accounted for 68% of recruited participants. The quality of evidence ranged from low to moderate owing to an unclear risk of bias across many studies, lack of blinding and low participant numbers for some outcomes. Eight of the studies compared LVRS versus standard medical care, one compared two closure techniques (stapling vs laser ablation), one looked at the effect of buttressing the staple line on the effectiveness of LVRS and one compared traditional 'resectional' LVRS with a non-resectional surgical approach. Participants completed a mandatory course of pulmonary rehabilitation/physical training before the procedure commenced. Short-term mortality was higher for LVRS (odds ratio (OR) 6.16, 95% confidence interval (CI) 3.22 to 11.79; 1489 participants; five studies; moderate-quality evidence) than for control, but long-term mortality favoured LVRS (OR 0.76, 95% CI 0.61 to 0.95; 1280 participants; two studies; moderate-quality evidence). Participants identified post hoc as being at high risk of death from surgery were those with particularly impaired lung function, poor diffusing capacity and/or homogenous emphysema. Participants with upper lobe-predominant emphysema and low baseline exercise capacity showed the most favourable outcomes related to mortality, as investigators reported no significant differences in early mortality between participants treated with LVRS and those in the control group (OR 0.87, 95% CI 0.23 to 3.29; 290 participants; one study), as well as significantly lower mortality at the end of follow-up for LVRS compared with control (OR 0.45, 95% CI 0.26 to 0.78; 290 participants; one study). Trials in this review furthermore provided evidence of low to moderate quality showing that improvements in lung function parameters other than forced expiratory volume in one second (FEV1), quality of life and exercise capacity were more likely with LVRS than with usual follow-up. Adverse events were more common with LVRS than with control, specifically the occurrence of (persistent) air leaks, pulmonary morbidity (e.g. pneumonia) and cardiovascular morbidity. Although LVRS leads to an increase in quality-adjusted life-years (QALYs), the procedure is relatively costly overall.

AUTHORS' CONCLUSIONS

Lung volume reduction surgery, an effective treatment for selected patients with severe emphysema, may lead to better health status and lung function outcomes, specifically for patients who have upper lobe-predominant emphysema with low exercise capacity, but the procedure is associated with risks of early mortality and adverse events.

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.

The minimal important difference for the St George's Respiratory Questionnaire in patients with severe COPD

The St George's Respiratory Questionnaire (SGRQ) is a validated, commonly used questionnaire for measuring quality of life in patients with chronic obstructive pulmonary disease (COPD). The current established minimal important difference (MID) for SGRQ scores in an average COPD population is -4 units. However, for patients with severe COPD, the MID has not been thoroughly validated. We re-determined the SGRQ MID for this patient group.115 severe COPD patients (forced expiratory volume in 1 s (FEV1) 26±9% of predicted, SGRQ score 62±11 units; mean±sd,) who participated in seven different bronchoscopic lung volume reduction clinical trials were included in the analysis. Anchor- and distribution-based methods were used to define the MID for SGRQ scores. FEV1, 6-min walk distance and residual volume were used as anchors.Combining both anchor- and distribution-based methods, we identified a SGRQ MID of -8.3 units at 1 month and -7.1 units at 6 months.This study proposes an alternative SGRQ MID for patients with severe COPD of -8.3 units at 1 month and -7.1 units at 6 months follow-up after intervention. Our new MID estimates could be applied for both interpreting SGRQ outcomes as well as sample size determination in future clinical trials investigating interventions in severe COPD patients.

Treatment of emphysema using bronchoscopic lung volume reduction coil technology: an update on efficacy and safety

In the last decade several promising bronchoscopic lung volume reduction (BLVR) treatments were developed and investigated. One of these treatments is BLVR treatment with coils. The advantage of this specific treatment is that it works independently of collateral flow, and also shows promise for patients with a more homogeneous emphysema disease distribution. Seven years ago, the very first patients were treated with BLVR coil treatment and currently large randomized, controlled trials are underway. The aim of this article is to review the available literature and provide an update on the current knowledge on the efficacy and safety of BLVR treatment with coils.