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

First real-time imaging of bronchoscopic lung volume reduction by electrical impedance tomography

BACKGROUND

Bronchoscopic lung volume reduction (BLVR) with one-way endobronchial valves (EBV) has better outcomes when the target lobe has poor collateral ventilation, resulting in complete lobe atelectasis. High-inspired oxygen fraction (FIO2) promotes atelectasis through faster gas absorption after airway occlusion, but its application during BLVR with EBV has been poorly understood. We aimed to investigate the real-time effects of FIO2 on regional lung volumes and regional ventilation/perfusion by electrical impedance tomography (EIT) during BLVR with EBV.

METHODS

Six piglets were submitted to left lower lobe occlusion by a balloon-catheter and EBV valves with FIO2 0.5 and 1.0. Regional end-expiratory lung impedances (EELI) and regional ventilation/perfusion were monitored. Local pocket pressure measurements were obtained (balloon occlusion method). One animal underwent simultaneous acquisitions of computed tomography (CT) and EIT. Regions-of-interest (ROIs) were right and left hemithoraces.

RESULTS

Following balloon occlusion, a steep decrease in left ROI-EELI with FIO2 1.0 occurred, 3-fold greater than with 0.5 (p < 0.001). Higher FIO2 also enhanced the final volume reduction (ROI-EELI) achieved by each valve (p < 0.01). CT analysis confirmed the denser atelectasis and greater volume reduction achieved by higher FIO2 (1.0) during balloon occlusion or during valve placement. CT and pocket pressure data agreed well with EIT findings, indicating greater strain redistribution with higher FIO2.

CONCLUSIONS

EIT demonstrated in real-time a faster and more complete volume reduction in the occluded lung regions under high FIO2 (1.0), as compared to 0.5. Immediate changes in the ventilation and perfusion of ipsilateral non-target lung regions were also detected, providing better estimates of the full impact of each valve in place.

TRIAL REGISTRATION

Not applicable.

Lung volume reduction surgery is safe and feasible after initial endobronchial valve treatment for emphysema patients

OBJECTIVES

Bronchoscopic lung volume reduction with endobronchial valves is a guideline treatment leading to improved pulmonary function, exercise tolerance and quality of life, in patients with advanced emphysema, severe hyperinflation and no collateral ventilation. After valve treatment, loss of the initial lung volume reduction effect can occur, as well as local valve-induced complications such as persistent haemoptysis. In these cases, a surgical lobectomy can be considered to achieve similar efficacy outcomes. We evaluated the safety and feasibility of a video-assisted thoracoscopic surgery lobectomy after valve treatment.

METHODS

This single-centre retrospective study included patients who underwent an elective lobectomy after previous valve treatment. Data were evaluated for safety and efficacy for the additional surgical procedure.

RESULTS

Twenty-one patients [73% female, median age 67 (7) years, forced expiratory volume in 1 s 29 (7) %pred, and residual volume 223 (58) %pred] were included. There was no 90-day mortality and there were no postoperative intensive care admissions. Pulmonary infections (14%) and prolonged air leak (14%) were the most common complications. In patients who underwent surgery due to loss or lack of effect of valve treatment, a lobectomy led to a significant improvement in pulmonary function; median forced expiratory volume in 1 s +75 (193) ml (P < 0.013), forced vital capacity +450 (572) ml (P = 0.001), residual volume -665 (715) ml (P = 0.005). In patients who underwent a lobectomy because of complications of valve treatment, all complications were resolved after surgery.

CONCLUSIONS

We demonstrate that an elective lobectomy after an initial valve treatment is safe and feasible and restores the lung volume reduction effect.

Safety of Home Discharge With a Chest Tube After Bronchoscopic Lung Volume Reduction Complicated by Persistent Airleak

BACKGROUND

The incidence of pneumothorax after bronchoscopic lung volume reduction (BLVR) using Zephyr (Pulmonx Corporation) endobronchial valves is ~26%. Many patients who develop a postprocedural pneumothorax require chest tube placement. If a persistent airleak is present, patients tolerating waterseal can be discharged home with a mini-atrium with a low risk of empyema.

METHODS

Data were collected on patients from the Epic (Epic System Corporation) electronic medical record between July 2019 and November 2022. Our retrospective study reviewed a total of 102 BLVR procedures. Twenty-six of these procedures were complicated by a pneumothorax post-BLVR (25%). After 24 procedures, patients were discharged home with a chest tube after a persistent airleak. The primary endpoint of the study was the incidence of intrapleural infection in this population. The secondary endpoint was the average length of time the chest tube was in place until outpatient removal.

RESULTS

Out of the 24 discharge events, 2 events (8.3%) were complicated by an intrapleural infection before chest tube removal. The average number of days requiring a chest tube until outpatient removal was 16.9 days, which is similar to the duration observed in patients discharged home with a chest tube after lung volume reduction surgery.

CONCLUSION

Discharging patients home with a chest tube after BLVR therapy is safe and may reduce hospital length of stay. Our study shows the incidence of intrapleural infection after home discharge with a chest tube after BLVR is low.

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.

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.

Pressure-Dependent Pneumothorax and Air Leak: Physiology and Clinical Implications

Pressure-dependent pneumothorax is a common clinical event, often occurring after pleural drainage in patients with visceral pleural restriction, partial lung resection, or lobar atelectasis from bronchoscopic lung volume reduction or an endobronchial obstruction. This type of pneumothorax and air leak is clinically inconsequential. Failure to appreciate the benign nature of such air leaks may result in unnecessary pleural procedures or prolonged hospital stay. This review suggests that identification of pressure-dependent pneumothorax is clinically important because the air leak that results is not related to a lung injury that requires repair but rather to a physiological consequence of a pressure gradient. A pressure-dependent pneumothorax occurs during pleural drainage in patients with lung-thoracic cavity shape/size mismatch. It is caused by an air leak related to a pressure gradient between the subpleural lung parenchyma and the pleural space. Pressure-dependent pneumothorax and air leak do not need any further pleural interventions.

[Surgical or bronchoscopic lung volume reduction for emphysema therapy]

More than 20 years ago, surgical lung volume reduction (LVRS) was already established in patients with advanced emphysema as a palliative therapy option that reduces respiratory distress and improves lung function and quality of life. In addition, bronchoscopic procedures (BLVR) aimed at volume reduction have existed for just over 10 years. The advantages and disadvantages of LVRS and BLVR are discussed in this article.

Response to endobronchial valve treatment: it's all about the target lobe

Background

Bronchoscopic lung volume reduction using endobronchial valves (EBV) has been shown to be beneficial for severe emphysema patients. The most important predictor of treatment response is absence of collateral ventilation between the treatment target and ipsilateral lobe. However, there are still a substantial number of nonresponders and it would be useful to improve the pre-treatment identification of responders. Presumably, predictors of response will be multifactorial, and therefore our aim was to explore whether we can identify response groups using a cluster analysis.

Methods

At baseline and 1 year follow-up, pulmonary function, exercise capacity and quality of life were measured. A quantitative chest computed tomography scan analysis was performed at baseline and 2-6 months follow-up. The cluster analysis was performed using a hierarchical agglomerative method.

Results

In total, 428 patients (69% female, mean±sd age 61±8 years, forced expiratory volume in 1 s 27±8% predicted, residual volume 254±50% pred) were included in our analysis. Three clusters were generated: one nonresponder cluster and two responder clusters. Despite solid technical procedures, the nonresponder cluster had significantly less clinical response after treatment compared to the other clusters. The nonresponder cluster was characterised by significantly less emphysematous destruction, less air trapping and a higher perfusion of the target lobe, and a more homogeneous distribution of emphysema and perfusion between the target and ipsilateral lobe.

Conclusions

We found that target lobe characteristics are the discriminators between responders and nonresponders, which underlines the importance of visual and quantitative assessment of the potential treatment target lobe when selecting patients for EBV treatment.

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.

[Bronchoscopic lung volume reduction]

Bronchoscopic lung volume reduction is as a safe and effective therapy for patients with advanced emphysema, suffering from breathlessness despite optimal medical therapy. By reducing hyperinflation, it improves lung function, exercise capacity and quality of life. The technique includes one-way endobronchial valves, thermal vapor ablation and endobronchial coils. Patient selection is the key to a successful therapy; hence the indication should be evaluated in a multidisciplinary emphysema team meeting. The procedure can lead to a potentially life-threatening complication. Therefore, an adequate post-procedural patient management is crucial.

Impact of pneumothorax-like pulmonary collapse caused by rapid bronchial obstruction: A case report of pneumothorax ex vacuo

We report two cases of pulmonary collapse that simulated pneumothorax on computed tomographic images and were caused by rapid complete bronchial obstruction. One patient was a 77-year-old woman with sudden dyspnea, and the other was an 83-year-old woman with sudden dyspnea who was infected with influenza A virus. Chest computed tomography revealed lobular complete atelectasis with an almost complete expansion of the other lobes of the right lung. Some air space in the right pleural cavity was also observed. Both cases were diagnosed as "pneumothorax" by primary doctors. We noted the disappearance of air density in the lumen of the right bronchus in both cases. We performed bronchoscopy before thoracic drainage and removed the obstruction. Immediately, the obstructed pulmonary lobes expanded, and the air space in the pleural cavity disappeared without thoracic drainage. In the literature, this pneumothorax-like pulmonary collapse is called as "pneumothorax ex vacuo."

Autologous Blood Patch Pleurodesis for Secondary Spontaneous Pneumothorax: A Narrative Review, a Retrospective Case Series and State of Play in the UK

INTRODUCTION

Treatment of prolonged air leak due to secondary spontaneous pneumothorax is challenging. Autologous blood patch pleurodesis (ABPP) is a treatment option. Previous evidence is reliant on single-centre series and underpowered trials and is mostly described in air leaks post cardiothoracic intervention. There are no United Kingdom (UK) wide data.

METHODS

Members of the UK Pleural Society were surveyed for their practice and for patients who underwent blood patch. There were 16 respondents from 333 members. Twelve had performed the procedure, and six had kept records and could submit data. Basic demographics, intervention and clinical details of patients were then collected. The study was sponsored by the Audit Department of Northumbria Healthcare NHS Foundation Trust (reference 8124), and Caldicott Clearance for data sharing was provided by the Trust's Information Goverance Board (reference C4221). There was no requirement for informed consent.

RESULTS

Data for 12 patients that received ABPP between 2014 and 2022 in six respiratory centres were assessed. The aetiology of the secondary pneumothoraces was mostly due to chronic obstructive pulmonary disease and end-stage interstitial lung disease. The patients had a median age of 75 years. The median air leak time before ABPP was 17 days. A total of 50-100 ml of blood was used for ABPP. Five patients had two attempts at ABPP. Air leak resolved in six patients (50%). Four patients had pleural apposition prior to ABPP. Four patients were diagnosed with hospital-acquired pneumonia following ABPP.

CONCLUSION

This is the only UK-wide retrospective case series of ABPP of 'medical' patients with secondary pneumothorax. There is widespread variation in care. No formal conclusions can be drawn, and much larger robust datasets are required. An application has been made to the European Respiratory Society to incorporate ABPP within the International Collaborative Effusion database.

Reversal of collateral ventilation using endoscopic polymer foam in COPD patients undergoing endoscopic lung volume reduction with endobronchial valves: A controlled parallel group trial

BACKGROUND AND OBJECTIVE

We have previously described reversal of collateral ventilation (CV) in a severe chronic obstructive pulmonary disease (COPD) patient with endoscopic polymer foam (EPF), prior to endoscopic lung volume reduction (ELVR) with valves. The aim of this study was to investigate the efficacy of this in a larger cohort and compare outcomes with a similar cohort with no CV.

METHODS

Patients with severe COPD, with the left upper lobe (LUL) targeted for ELVR, were assessed for CV with high resolution computed tomography (HRCT). If fissure completeness was >95% they were enrolled as controls for valves alone (endobronchial valve control group [EBV-CTRL]). If fissure completeness was 80%-95%, defects were mapped to the corresponding segment, where EPF was instilled following confirmation of CV with CHARTIS. EBVs were inserted 1 month afterwards.

RESULTS

Fourteen patients were enrolled into both arms. After 6 months, there were significant improvements in both groups in forced expiratory volume in 1 s (FEV1; +19.7% EPF vs. +27.7% EBV-CTRL, p < 0.05); residual volume (RV; -16.2% EPF vs. -20.1% EBV-CTRL, p = NS); SGRQ (-15.1 EPF vs. -16.6 EBV-CTRL p = NS) and 6 min walk (+25.8% EPF [77.2 m] vs. +28.4% [82.3 m] EBV-CTRL p = NS). Patients with fissural defects mapped to the lingula had better outcomes than those mapped to other segments (FEV1 +22.9% vs. +16.3% p < 0.05). There were no serious adverse reactions to EPF.

CONCLUSION

EPF successfully reverses CV in severe COPD patients with a left oblique fissure that is 80%-95% complete. Following EBV, outcomes are similar to patients with complete fissures undergoing ELVR with EBV alone. EPF therapy to reverse CV potentially increases the number of COPD patients suitable for ELVR with minimal adverse reactions.

Endobronchial valves: 1st Multicenter retrospective study on the 2-step approach

BACKGROUND

Although the endobronchial valves (EBV) were successfully developed as treatment for severe emphysema, its main complication, pneumothorax, remained an important concern.

OBJECTIVE

To assess whether the placement of Zephyr© endobronchial valves throughout 2 procedures instead of 1 minor the frequency of pneumothorax without lowering the benefits of such treatment.

METHODS

This retrospective study was conducted in 15 pulmonology department in France. All the patients met the inclusion criteria of the recommendation set by the expert panel on the Endoscopic Lung Volume Reduction (ELVR) updated in 2019. As recommended, all the scan were analyzed with the StratX© (PulmonX Corporation, Redwood city, CA) protocol, and completed by a Chartis© (PulmonX Corporation, Redwood city, CA) in case of questionable fissure. During the first procedure, all but the most proximal sub-segment of the targeted lobe were occluded. One month after, EBV were placed in the bronchus of the last subsegment. All patients were evaluated before and 3 months after the second procedure.

RESULTS

Between March 2019 and December 2020, 96 patients received EBV treatment. 12 patients (12.5%) presented a pneumothorax (3 after the 1st step and 9 after the 2nd procedure). Beside pneumothorax, the main adverse event was exacerbation (10.4%) and pneumonia (4.1%). No death were reported. Significant improvement were found for FEV1 (14.6 ± 25.3%), RV (- 0.69 ± 2.1 L), 6MWT (34.8 ± 45.9 m), BODE Score (-1.41 ± 1.41pts), and mMRC scale (-0.85 ± 0.7pts). These results are compared not only to the results previously published using the usual approach but also to our previous publication evaluating the 2-step approach. Some patients presented authentic segmental atelectasis despite infralobar treatment.

CONCLUSION

Placing EBV during 2 procedures instead of one led to a significant decrease of post treatment pneumothoraces without increasing the rate of other complications. It does not seem to alter the benefits of such therapy for severe emphysema. These results must be confirmed by launching a multicenter, prospective, randomized, controlled study to compare the frequency of pneumothorax and the efficacy of this new approach with the usual one-time procedure.

Long-Term Follow-Up of Intralobar Bullae After Endobronchial Valve Treatment for Emphysema

Endoscopic lung volume reduction using unidirectional endobronchial valves is a new technique in the treatment of patients with severe emphysema. However, the movements of the thoracic structures after endobronchial valves insertion are still unpredictable We report the unusual outcome of six patients after valves insertion in the left upper lobe. They all developed a complete atelectasis of the target lobe, a pneumothorax and sequential genuine bullae in the treated left lung of unknown etiology. The chest CT scan prior to the valves insertion was unremarkable. Three patients developed an air–liquid level in the bullae the day before a bacterial infection of their left lower lobe. The three other patients had an uneventful spontaneous resolution of their bullae at long-term follow-up. Therefore, a conservative attitude should be followed in this particular setting.

Complications of Endobronchial Valve Placement for Bronchoscopic Lung Volume Reduction: Insights From the Food and Drug Administration Manufacturer and User Facility Device Experience (MAUDE)

BACKGROUND

Patients with advanced emphysema experience breathlessness due to impaired respiratory mechanics and diaphragm dysfunction. Bronchoscopic lung volume reduction (BLVR) is a minimally invasive bronchoscopic procedure done to reduce hyperinflation and air trapping, promoting atelectasis in the targeted lobe and allowing improved respiratory mechanics. Real-world data on safety and complications outside of clinical trials of BLVR are limited.

METHODS

We queried the US Food and Drug Administrations (FDA) Manufacturers and User Device Experience database from May 2019 to June 2020 for reports involving BLVR with endobronchial valve (EBV) placement. Events were reviewed for data analysis.

RESULTS

We identified 124 cases of complications during BLVR with EBV implantation. The most-reported complication was pneumothorax (110/124, 89%), all of which required chest tube placement. A total of 54 of these cases (54/110, 49%) were complicated by persistent air leak requiring additional interventions. Repeat bronchoscopy was needed to remove the valves in 28 patients, 12 were discharged with a Heimlich valve, and 10 had an additional pleural catheter placed. The other complications of BLVR with EBV placement included respiratory failure (6/124, 5%), pneumonia (4/124, 3%), hemoptysis (2/124, 1.6%), valve migration (1/124, 1%), and pleural effusion (1/124, 1%). A total of 14 deaths were reported during that year.

CONCLUSION

Pneumothorax is the most-reported complication for BLVR with EBV placement, and in 65% of cases, pneumothorax is managed without removing valves. Importantly, 14 deaths were reported during that timeframe. Further studies are needed to estimate the true magnitude of the complications associated with BLVR.

Position statement on endoscopic lung volume reduction in South Africa: 2022 update

Chronic obstructive pulmonary disease (COPD) remains one of the most common causes of morbidity and mortality in South Africa. Endoscopic lung volume reduction (ELVR) was first proposed by the South African Thoracic Society (SATS) for the treatment of advanced emphysema in 2015. Since the original statement was published, there has been a growing body of evidence that a certain well-defined sub-group of patients with advanced emphysema may benefit from ELVR, to the point where the current Global Initiative for Chronic Obstructive Lung Disease (GOLD) Guidelines and the United Kingdom National Institute for Health and Care Excellence (NICE) advocate the use of endoscopic valves based on level A evidence. Patients aged 40 - 75 years with severe dyspnoea (COPD Assessment Test score ≥10) despite maximal medical therapy and pulmonary rehabilitation, with forced expiratory volume in one second (FEV₁) 20 - 50%, hyperinflation with residual volume (RV) >175% or RV/total lung capacity (TLC) >55% and a six-minute walking distance (6MWD) of 100 - 450 m (post-rehabilitation) should be referred for evaluation for ELVR, provided no contraindications (e.g. severe pulmonary hypertension) are present. Further evaluation should focus on the extent of parenchymal tissue destruction on high-resolution computed tomography (HRCT) of the lungs and interlobar collateral ventilation (CV) to identify a potential target lobe. Commercially available radiology software packages and/or an endobronchial catheter system can aid in this assessment. The aim of this statement is to provide the South African medical practitioner and healthcare funders with an overview of the practical aspects and current evidence for the judicious use of the valves and other ELVR modalities which may become available in the country.

Bronchoscopic Lung Volume Reduction for Emphysema: Review and Update

In carefully selected patients with severe chronic obstructive pulmonary disease, characterized by emphysema and hyperinflation, lung volume reduction is an option to reduce lung hyperinflation, improve lung function, quality of life, and exercise capacity. Currently, there are several bronchoscopic and surgical treatment options to achieve lung volume reduction. It is important to carefully phenotype these patients, to select the optimal treatment option, with consideration of possible adverse events or contraindications, and it is highly recommended to discuss these treatment strategies in a multidisciplinary team. The treatment with one-way endobronchial valves has been investigated most extensively and more data are available regarding the treatment of more "marginal cases," or subsequent lung volume reduction surgery. Other bronchoscopic lung volume reduction options include treatment with coils, thermal vapor ablation, and sclerosant agents. In this review, we aim to summarize the current clinical evidence on the bronchoscopic lung volume reduction therapies and important aspects regarding optimal patient selection.