Clinical and radiological outcome following pneumothorax after endoscopic lung volume reduction with valves

Surgical and bronchoscopic pulmonary function-improving procedures in lung emphysema

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Clinical outcomes and quantitative CT analysis after bronchoscopic lung volume reduction using valves for advanced emphysema

Background

Bronchoscopic lung volume reduction (BLVR) using Zephyr endobronchial valve (EBV) and intrabronchial valve (IBV) has been shown to improve lung function and exercise capacity in severe emphysema. However, changes in airway structures and whether these are related to the clinical improvements remain unclear.

Methods

A retrospective study was performed on patients treated with BLVR. We compared changes in 2nd-, 3rd-, and 4th-generation bronchial structures after therapy, including wall thickness (WT), percentage of wall thickness (WT%), intraluminal area (LA), wall area (WA), and WA%. Responder and non-responder subgroup analysis according to minimum clinically important difference (MCID) which was defined as an improvement of 15% in forced expiratory volume in 1 s (FEV₁) and 26 m in 6 min walk distance (6MWD) was conducted.

Results

Of the 19 patients, 11 were treated with EBV and 8 with IBV. In ipsilateral non-target lobes, WT% decreased significantly in 3rd-generation bronchi at 1 month, 3, and 6 months, as well as their WA% at 1 month and 6 months. Non-responders, who were unable to achieve MCID, showed no consistent bronchial wall changes. And their LA of 3rd-generation bronchi decreased especially at 1 month. After BLVR, the target lobe volume decreased significantly until 12 months of follow-up. The volume of ipsilateral lobes could increase correspondingly and achieve the best improvements at 6 months. The contralateral lung volume showed slight amelioration but there was no statistical significance.

Conclusions

Both airway structures and lung volumes showed changes after BLVR. The 3rd- and 4th-bronchial walls tend to be thinner, which were consistent with clinical improvements. Further studies are needed to prove this conclusion and find detect potential mechanics.

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

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

Endobronchial Valves for the Treatment of Advanced Emphysema

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

Consolidating Lung Volume Reduction Surgery After Endoscopic Lung Volume Reduction Failure

BACKGROUND

Bronchoscopic valve placement constitutes an effective endoscopic lung volume reduction (ELVR) therapy in patients with severe emphysema and low collateral ventilation. After the most destroyed lobe is occluded with valves, significant target lobe volume reduction leads to improvements in lung function, exercise capacity, and quality of life. The effects are not consistent in some patients, leading to long-term therapy failure. We hypothesized that surgical lung volume reduction (LVRS) would reestablish ELVR short-term clinical improvements after ELVR long-term failure.

METHODS

This retrospective single-center analysis included all patients who underwent consolidating LVRS by lobectomy after long-term failure of valve therapy between 2010 and 2015. Changes in forced expiratory volume in 1 second, residual volume, 6-minute walking distance, and Modified Medical Research Council dyspnea score 90 days after ELVR and LVRS were analyzed, and the outcomes of both procedures were compared.

RESULTS

LVRS was performed in 20 patients after ELVR failure. A lower lobectomy was performed in 90%. The 30-day mortality of the cohort was 0% and 90-day mortality was 5% (1 of 20). The remaining 19 patients showed a significant increase in forced expiratory volume in 1 second (+27.5% ± 19.4%) and a reduction in residual volume (-21.0% ± 17.4%) and total lung capacity (-11.1% ± 11.1%). This resulted in significant improvements in exercise tolerance (6-minute walking distance: +56 ± 60 m) and relief of dyspnea (ΔModified Medical Research Council: -1.8 ± 1.4 points.).

CONCLUSIONS

Consolidating LVRS by lobectomy after failure of a previously successful ELVR is feasible and results in significant symptom relief and improvement of lung function.

Computed Tomography Imaging for Novel Therapies of Chronic Obstructive Pulmonary Disease

Novel therapeutic options in chronic obstructive pulmonary disease (COPD) require delicate patient selection and thus demand for expert radiologists visually and quantitatively evaluating high-resolution computed tomography (CT) with additional functional acquisitions such as paired inspiratory-expiratory scans or dynamic airway CT. The differentiation between emphysema-dominant and airway-dominant COPD phenotypes by imaging has immediate clinical value for patient management. Assessment of emphysema severity, distribution patterns, and fissure integrity are essential for stratifying patients for different surgical and endoscopic lung volume reduction procedures. This is supported by quantitative software-based postprocessing of CT data sets, which delivers objective emphysema and airway remodelling metrics. However, the significant impact of scanning and reconstruction parameters, as well as intersoftware variability still hamper comparability between sites and studies. In earlier stage COPD imaging, it is less clear as to what extent quantitative CT might impact decision making and therapy follow-up, as emphysema progression is too slow to realistically be useful as a mid-term outcome measure in an individual, and longitudinal data on airway remodelling are still very limited.

Long-term follow up after endoscopic valve therapy in patients with severe emphysema

BACKGROUND AND OBJECTIVE

Endoscopic valve therapy is a treatment modality in patients with advanced emphysema and absent interlobar collateral ventilation (CV). So far, long-term outcome following valve implantation has been insufficiently evaluated. The aim of this study was to investigate the real-world efficacy of this interventional therapy over 3 years.

METHODS

From 2006 to 2013, 256 patients with severe emphysema in whom absent CV was confirmed underwent valve therapy. The 3-year effectiveness was evaluated by pulmonary function testing (VC, FEV1, RV, TLC), 6-minute-walk test (6-MWT) and dyspnea questionnaire (mMRC). Long-term outcome was also assessed according to the radiological outcome following valve placement.

RESULTS

Of 256 patients treated with valves, 220, 200, 187, 100 and 66 patients completed the 3-month, 6-month, 1-year, 2-year and 3-year follow-up (FU) visit, respectively. All lung function parameters, 6-MWT and mMRC were significantly improved at 3- and 6-month FU. At 1-year FU, patients still experienced a significant improvement of all outcome parameters expect VC (L) and TLC (%). At 2 years, RV (L and %) and TLC (L and %) remained significantly improved compared to baseline. Three years after valve therapy, sustained significant improvement in mMRC was observed and the proportion of patients achieving a minimal clinically important difference from baseline in RV and 6-MWT was still 71% and 46%, respectively. Overall, patients with complete lobar atelectasis exhibited superior treatment outcome with 3-year responder rates to FEV1, RV and 6-MWT of 10%, 79% and 53%, respectively.

CONCLUSIONS

Patients treated by valves experienced clinical improvement over 1 year following valve therapy. Afterwards, clinical benefit gradually declines more likely due to COPD progression.

Competence in bronchoscopic treatments in emphysema

Bronchoscopic lung volume reduction (BLVR) has been proven to be effective in patients with severe emphysema. These techniques are divided into two groups: non-blocking devices that are independent of collateral ventilation and blocking devices that are dependent on collateral ventilation so the choice of the target lobe with inadequate scissors is crucial for the success of the treatment. Current evidences suggest that not all classes and phenotypes of emphysema will benefit from BLVR, and that each technique appears to provide a greater benefit to specific sub-groups of patients. Careful patient selection is imperative to prevent insertion in patients unlikely to gain clinical benefits as well as wasteful expenditure. The Chartis system represents the gold standard for measuring fissure integrity and is a direct measurement method. Indirect method is instead the TC study which, thanks to the development of software for quantitative analysis, allows us to obtain reliable measurements of regional density of parenchyma, airway thickness and scissor integrity. BLVR is a highly complex procedure: a first-level competence is a pre-requisite for admission to training. The practical training must be based on discussion of clinical cases and the insertion techniques of the different devices on plastic or animal models, or on cadavers. A specific course, offering final certification, has been developed on the use of Zephyr valves.

Complications related to endoscopic lung volume reduction for emphysema with endobronchial valves: results of a multicenter study

Background

Despite bronchoscopic lung volume reduction (BLVR) with valves is a minimally invasive treatment for emphysema, it can associate with some complications. We aimed at evaluating the rate and type of complications related to valve treatment and their impact on clinical outcomes.

Methods

It is a retrospective multicenter study including all consecutive patients with severe heterogeneous emphysema undergoing BLVR with endobronchial valve treatment and developed any complications related to this procedure. The type of complication, the time of onset, the treatment required and the out-come were evaluated. Response to treatment was assessed according to the minimal clinically important difference (MCID) as follows: an improvement of ≥15% in forced expiratory volume in one second (FEV₁); of -8% in residual volume (RV); of ≥26 m in 6-minnute walking distance (6MWD); and of ≥4 points on the St. George's Respiratory Questionnaire (SGRQ). Target lobe volume reduction (TLVR) ≥350 mL was considered significant.

Results

One hundred and seven out of 423 (25.3%) treated patients had complications related to valve treatment including pneumothorax (17.3%); pneumonia (1.7%), chronic obstructive pulmonary disease (COPD) exacerbation (0.9%), respiratory failure (1.4%), valve migration (2.1%), and hemoptysis (1.9%). In all cases complications resolved with appropriate treatment including removal of valves in 21/107 cases (19.6%). Patients with TLVR ≥350 mL (n=64) vs. those <350 mL (n=43) had a statistically significant higher improvement in FEV₁ (19.0%±3.9% vs. 3.0%±0.9%; P=0.0003); in RV (-10.0%±4.8% vs. -4.0%±2.9%; P=0.002); in 6MWD (33.0±19.0 vs. 12.0±6.3 metres; P=0.001); and in SGRQ (-15.0±2.9 vs. -8.0±3.5 points; P=0.01). Only patients with TLVR ≥350 mL met or exceeded the MCID cut-off criteria for FEV₁ (19.0%±3.9%), RV (-10.0%±4.8%), 6MWT (33.0±19.0 metres), and SGQR (-15.0±2.9 points). Five patients (1.2%) died during follow-up for causes not related to valves treatment neither to any of the complications described.

Conclusions

Valve treatment is a safe and reversible procedure. The presence of complications seems not to have a significant impact on clinical outcome in patients with lobar atelectasis. Due to poor clinical conditions and possible complications, BLVR should be performed in high volume centers with a multidisciplinary approach.

The minimal important difference for target lobe volume reduction after endoscopic valve therapy

Objective

Endoscopic valve therapy aims at target lobe volume reduction (TLVR) that is associated with improved lung function, exercise tolerance and quality of life in emphysema patients. So far, a TLVR of >350 mL was considered to be indicative of a positive response to treatment. However, it is not really known what amount of TLVR is crucial following valve implantation.

Patients and methods

TLVR, forced expiratory volume in 1 second (FEV₁), residual volume (RV) and 6-minute walk distance (6-MWD) were assessed before and 3 months after valve implantation in 119 patients. TLVR was calculated based on computed tomography (CT) scan analysis using imaging software (Apollo; VIDA Diagnostics). Minimal important difference estimates were calculated by anchor-based and distribution-based methods.

Results

Patients treated with valves experienced a mean change of 0.11 L in FEV₁, −0.51 L in RV, 44 m in 6-MWD and a TLVR of 945 mL. Using a linear regression and receiver operating characteristic analysis based on two of three anchors (ΔFEV₁, ΔRV), the estimated minimal important difference for TLVR was between 890 and 1,070 mL (ie, 49%–54% of the baseline TLV).

Conclusion

In future, a TLVR between 49% and 54% of the baseline TLV, should be used when interpreting the clinical relevance.

Pleural Adhesion Assessment as a Predictor for Pneumothorax after Endobronchial Valve Treatment

BACKGROUND

Pneumothorax after bronchoscopic lung volume reduction using one-way endobronchial valves (EBVs) in patients with advanced emphysema occurs in approximately 20% of patients. It is not well known which factors predict the development of pneumothorax.

OBJECTIVE

To assess whether pleural adhesions on pretreatment high-resolution computed tomography (HRCT) scans are associated with pneumothorax occurrence after EBV treatment.

METHODS

HRCT scan analyses were performed on all patients who received EBV treatment in a randomized controlled trial. Three blinded readers scored adhesions by number and by measuring the longest axis of each pleural adhesion in the treated lung. The Pleural Adhesion Score (PAS) was calculated by adding 1 point for each small pleural lesion (<1 mm), 5 points for each medium-sized lesion (1-5 mm), and 10 points for each large lesion (>5 mm).

RESULTS

The HRCT scans of 64 treated patients were assessed, of whom 14 developed pneumothorax. Patients who developed pneumothorax had a higher median number of pleural adhesions, 2.7 (IQR 1.9-4) compared to 1.7 (1-2.7) adhesions in the group without pneumothorax (p < 0.01). The PAS in the group with pneumothorax was higher compared to that in the group without: 14.3 (12.4-24.1) versus 6.7 (3.7-11.2) (p < 0.01). A threshold PAS of ≥12 was associated with a higher risk of pneumothorax (OR 13.0, 95% CI 3.1-54.9). A score <12 did not rule out the occurrence of pneumothorax.

CONCLUSION

A higher number of pleural adhesions on HRCT with a subsequent higher PAS in the treated lung is associated with a higher occurrence of pneumothorax after EBV treatment.