Bronchoscopic interventions for chronic obstructive pulmonary disease

A Quantitative Computed Tomography Analysis of Fissure Integrity and Emphysema Destruction in Japanese Patients with Severe Chronic Obstructive Pulmonary Disease

Objective Bronchoscopic lung volume reduction (BLVR) using a one-way endobronchial valve (EBV) can provide clinically meaningful benefits to chronic obstructive pulmonary disease (COPD) patients. Although the Japanese Pharmaceuticals and Medical Devices Agency approved EBVs in November 2022, information regarding the number of Japanese patients with severe COPD eligible for BLVR treatment is still lacking. We therefore screened computed tomography (CT) images of patients with severe COPD using a quantitative CT (QCT) analysis to estimate the proportion of candidates eligible for BLVR treatment with an EBV. Methods CT scans of COPD patients with Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages 3 and 4 were retrospectively analyzed using QCT to evaluate fissure integrity and tissue destruction. The difference in volume-weighted percentage was measured using the density scores of the target lobe and ipsilateral non-target lobe at -910 Hounsfield units. The target lobe was defined as the most affected lobe, with an emphysema destruction score of >50% for each patient. Results High-resolution CT scans of 32 patients (GOLD 3=19, GOLD 4=13) were analyzed. The target lobe could not be identified in 1 patient, whereas the target lobes for 8 patients were not surrounded by fissures with ≥80% completeness. Conversely, in 13 patients, the target lobes were surrounded by fissures with >95% completeness. The remaining 10 patients had fissure completeness between 80% and 95% at the target lobes and were considered candidates for collateral ventilation assessment. Conclusion A QCT analysis showed that 23 of 32 patients with severe COPD could be considered for a thorough examination of BLVR treatment with EBV.

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

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

Determining Static Hyperinflation in Patients with Severe Emphysema: Relation Between Lung Function Parameters and Patient-Related Outcomes

BACKGROUND

Bronchoscopic lung volume reduction techniques are minor invasive treatment modalities for severely hyperinflated emphysema patients. The severity of static lung hyperinflation determines eligibility and success rate for these treatments. However, it is not exactly known what parameter should be used to optimally reflect hyperinflation. Commonly used parameters are residual volume (RV) and the RV/Total lung capacity (TLC) ratio. Other parameters reflecting hyperinflation are Inspiratory Capacity/TLC and forced vital capacity.

OBJECTIVES

To define which of these function parameters is the most optimal reflection of hyperinflationin in relation to patient-related outcomes.

METHODS

In a retrospective cohort study, data from measurements during baseline visits of eight studies were pooled. Primary outcomes were RV/TLC ratio and RV as percentage of predicted (RV%pred), both measured by bodyplethysmography, compared to the patient-related outcome variables: 6-min walk distance (6MWD), the St. George's Respiratory Questionnaire (SGRQ), and the modified Medical Research Council (mMRC).

RESULTS

Two hundred seventy-four COPD patients (mean age 59 years; 66% female), FEV₁ 0.74 ± 0.28 L, RV 4.94 ± 1.06 L, 6MWD of 339 ± 95 m, were included in the analysis. Significant correlations (all p < 0.01) were found between RV%pred and 6MWD (r =  - 0.358), SGRQ (r = 0.184), and mMRC (r = 0.228). Also, there was a significant correlation between RV/TLC ratio and 6MWD (r =  - 0.563), SGRQ (r = 0.289) and mMRC (r = 0.354). Linear regression analyses showed that RV/TLC ratio was a better predictor of patient outcomes than RV%pred.

CONCLUSION

This study demonstrates that both RV/TLC ratio and RV%pred are relevant indicators of hyperinflation in patients with severe emphysema in relation to patient-related outcomes. RV/TLC ratio is more strongly related to the patient-related outcomes than RV%pred.

A Concentric Tube Robot System for Rigid Bronchoscopy: A Feasibility Study on Central Airway Obstruction Removal

New robotic systems have recently emerged to assist with peripheral lung access, but a robotic system for rigid bronchoscopy has yet to be developed. We describe a new robotic system that can deliver thin robotic manipulators through the ports of standard rigid bronchoscopes. The manipulators bend and elongate to provide maneuverability of surgical tools at the endoscope tip, without endoscope motion. We describe an initial feasibility study on the use of this system to bronchoscopically treat a central airway obstruction (CAO). CAO is prevalent and can be life-threatening in patients with large tumors, and conventional rigid bronchoscopic treatments place patients at risk of complications including broken teeth, neck trauma and damage to oropharyngeal structures due to significant forces induced by bronchoscope tilting and manipulation. In this study, we used an ex vivo ovine airway model to demonstrate the ability of a physician using the robotic system to efficiently remove tissue and restore the airway. Pre- and post-operative CT scans showed that the robot was able to reduce the degree of airway obstruction stenosis from 75 to 14% on average for five CAO resections performed in an ex vivo animal model. Using cadaver experiments, we demonstrated the potential of the robotic system to substantially reduce the intraoperative forces applied to the patient's head and neck (from 80.6 to 4.1 N). These preliminary results illustrate that CAO removal is feasible with our new rigid bronchoscopy robot system, and that this approach has the potential to reduce forces applied to the patient due to bronchoscope angulation, and thereby reduce the risk of complications encountered during CAO surgery.

Bronchoscopic Lung Volume Reduction with Endobronchial Zephyr Valves for Severe Emphysema: A Systematic Review and Meta-Analysis

BACKGROUND

Endoscopic lung volume reduction using Zephyr® valves has been recently adopted as a treatment option for patients with severe emphysema without collateral ventilation (CV).

OBJECTIVES

To assess the efficacy and safety of Zephyr valves in such a population.

METHODS

Studies were identified from MEDLINE and EMBASE databases. All searches were current until June 2018. We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) evaluating the efficacy and safety of Zephyr. We defined as outcome: change in forced expiratory volume in 1 s (FEV1), in the 6-min walking test (6MWT), in the St George's Respiratory Questionnaire (SGRQ), and in residual volume (RV). Safety analysis included relative risk (RR) of pneumothorax. We assessed the quality of the evidence using GRADE.

RESULTS

7 RCTs reported on Zephyr valves and 5 RCTs included only patients without CV. Zephyr improved FEV1 with a mean difference (MD) of 17.36% (CI, 9.28-25.45, I2 = 78%). Subgroup analysis showed significant FEV1 improvement following Zephyr placement in patients with heterogeneous distribution: MD = 21.78% (CI, 8.70-34.86, I2 = 89%) and 16.27% (CI, 8.78-23.76, I2 = 0%) in patients with homogeneous emphysema. Studies with a follow-up of 3 months reported FEV1 MD = 17.19% (CI, 3.16-31.22, I2 = 89%) compared to studies with a follow-up of 6-12 months, which showed a consistent improvement of FEV1 MD = 17.90% (CI, 11.47-24.33, I2 = 0%). Zephyr also showed improvement of SGRQ, 6MWT, and RV. RR of pneumothorax was 6.32 (CI, 3.74-10.67, I2 = 0%).

CONCLUSION

In this population, Zephyr valves provided significant and clinically meaningful short-term improvements in either homogeneous or heterogeneous emphysema without CV but with an increase in adverse events.

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.

Lung volume reduction with endobronchial coils for patients with emphysema

The lung volume reduction coil treatment is a minimally invasive bronchoscopic treatment option for emphysema patients who suffer from severe hyperinflation. The treatment is aimed at a large group of patients where lung volume reduction surgery and bronchoscopic lung volume reduction using endobronchial valves are no option, or alternatively, can be offered as a bridge to lung transplantation. The nitinol coil exhibits a shape memory effect and is biologically inert. The lung volume reduction coil procedure is performed in two separate treatment sessions, targeting one lobe per session, with the contralateral lobe being treated 4 to 8 weeks after the first session. In one treatment session, around 10 to 14 coils, thereby treating an entire lobe, are being placed. Selecting optimally treated, symptomatic chronic obstructive pulmonary disease (COPD) patients with emphysema and severe hyperinflation, while avoiding significant airway disease such as asthma, chronic bronchitis and bronchiectasis, is key to achieve treatment success. Three randomized clinical trials investigating lung volume reduction coil treatment have been published until now, reporting the results of 452 treated patients up to 12 months after coil treatment. Lung volume reduction coil treatment results in significant improvement of pulmonary function outcomes and quality of life in patients with severe hyperinflation. The most common complications of lung volume reduction coil treatment are: COPD exacerbations, pneumonia, Coil Associated Opacity and an increased risk of pneumothorax. The purpose of this article is to describe the coil technique and review the available literature regarding effect, safety and future perspectives of lung volume reduction with coils for emphysema patients.

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.

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.

Coils for the Treatment of Advanced Emphysema: A Growing Body of Evidence and Routine Experience

Endoscopic lung volume reduction (ELVR) mainly comprises endobronchial valves (EBV) and endobronchial coil (EBC) implants. EBV aims to occlude the most diseased and/or hyperinflated lobe thus inducing complete atelectasis. EBC therapy was developed a few years ago and is applicable independently of collateral flow and in patients presenting with disease dispersed throughout the upper and lower lobes. Bronchoscopic lung volume reduction with EBC is feasible in a wider range of patients (irrespective of collateral flow or disease homo/heterogeneity) than for EBV, and provides clinical benefits in the short-term, associated to an acceptable safety profile. The growing clinical and commercial experience of ELVR with nitinol coils will be reviewed in this article.

The fissure: interlobar collateral ventilation and implications for endoscopic therapy in emphysema

In patients with severe emphysema, bronchoscopic lung volume reduction using one-way valves is a promising therapeutic option to improve lung function and quality of life. The goal of this treatment is to achieve a complete lobar atelectasis. In a significant proportion of patients, this atelectasis cannot be achieved due to interlobar collateral ventilation. This collateral ventilation is generated through incomplete lobar fissures. Therefore, only patients with complete fissures and no collateral ventilation can be selected for endobronchial therapy with one-way valves.

Incomplete fissures are very common and exhibit a great variation in anatomy. The reported prevalence is 17%–85% for the right major fissure, 19%–74% for the left major fissure, and 20%–90% for the minor fissure. There are several methods of measuring or predicting the presence of collateral ventilation, with computed tomography (CT)-fissure analysis and the Chartis measurement being the most important. CT-fissure analysis is an indirect method to measure the completeness of fissures as a surrogate for collateral ventilation. The Chartis system is an endobronchial method to directly measure the presence of collateral ventilation. Both methods have unique value, and the combination of both can accurately predict the treatment response to the bronchoscopic placement of endobronchial valves. This review provides an in-depth view of lung fissure and collateral ventilation to help understand its importance in selecting the appropriate patients for new emphysema treatments and thus avoid useless treatment in unsuitable patients.

Bronchoscopic lung volume reduction in chronic obstructive pulmonary disease: History and progress

Emphysema is one of the pathological manifestations of chronic obstructive pulmonary disease (COPD), which leads to lung hyperinflation, decreased activity of the diaphragm, decreased compliance of the lung, and difficulties in gas exchange. The clinical effect of pharmacological treatment for patients with severe emphysema is limited. In recent years, the emergence of bronchoscopic lung volume reduction (BLVR) has opened up the possibility for the management of COPD with severe emphysema. The article aims to summarize the development, procedure, and methodology of BLVR as well as its clinical efficacy.

Recent updates in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD), characterized by chronic airways inflammation and progressive airflow limitation, is a common, preventable and treatable disease. Worldwide, COPD is a major cause of morbidity and mortality; smoking tobacco is the most important risk factor. This translational review of recent updates in COPD care for the primary care audience, includes recommendations from the 2015 Global Initiative for chronic obstructive lung disease (GOLD) report on diagnosis, pharmacological and non-pharmacological treatment, prevalence of comorbidities, management of exacerbations and the asthma and COPD overlap syndrome, with a focus on the importance and benefit of physical activity and exercise in COPD patients. Exacerbations and comorbidities contribute to the overall severity of COPD in individual patients. Management of exacerbations includes reducing the impact of the current exacerbation and preventing development of subsequent episodes. Healthcare professionals need to be alert to comorbidities, such as cardiovascular disease, anxiety/depression, lung cancer, infections and diabetes, which are common in COPD patients and can have a significant impact on HRQoL and prognosis. Pulmonary rehabilitation is recommended by a number of guidelines for all symptomatic COPD patients, regardless of severity, and involves exercise training, patient education, nutritional advice and psychosocial support. At all stages of COPD, regular physical activity and exercise can aid symptom control, improve HRQoL, reduce rates of hospitalization, and improve morbidity and respiratory mortality. Healthcare professionals play a pivotal role in improving HRQoL and health-related outcomes in COPD patients to meet their specific needs and in providing appropriate diagnosis, management and advice on smoking cessation.

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.

Long-term follow-up after bronchoscopic lung volume reduction treatment with coils in patients with severe emphysema

Background and objective

Bronchoscopic lung volume reduction coil (LVR-coil) treatment has been shown to be safe and clinically effective in patients with severe emphysema in the short term; however, long-term safety and effectiveness has not been evaluated. The aim of this study was to investigate the long-term safety and effectiveness of LVR-coil treatment in patients with severe emphysema.

Methods

Thirty-eight patients with severe emphysema (median age is 59 years, forced expiratory volume in 1 s is 27% predicted) who were treated in LVR-coil clinical trials were invited for a voluntary annual visit. Safety was evaluated by chest X-ray and recording of adverse events and by efficacy by pulmonary function testing, 6-min walk distance (6MWD) and questionnaires.

Results

Thirty-five patients visited the hospital 1 year, 27 patients 2 years and 22 patients 3 years following coil placement. No coil migrations were observed on X-rays. At 1-year follow-up, all clinical outcomes significantly improved compared with baseline. At 2 years, residual volume % pred, modified Medical Research Council (mMRC) and the SGRQ score were still significantly improved. At 3 years, a significant improvement in mMRC score remained, with 40% of the patients reaching the 6MWD minimal important difference, and 59% for the St George's Respiratory Questionnaire (SGRQ) minimal important difference.

Conclusions

Follow-up of the patients treated with LVR-coils in our pilot studies showed that the coil treatment is safe with no late pneumothoraces, coil migrations or unexpected adverse events. Clinical benefit gradually declines over time; at 3 years post-treatment, around 50% of the patients maintained improvement in 6MWD, SGRQ and mMRC.