Early results of endoscopic lung volume reduction for emphysema

Application of 3D computed tomography in emphysematous parenchyma patients scheduled for bronchoscopic lung volume reduction

Bronchoscopic lung volume reduction (BLVR) is a feasible, safe, effective and minimally invasive technique to significantly improve the quality of life of advanced severe chronic obstructive pulmonary disease (COPD). In this study, three-dimensional computed tomography (3D-CT) automatic analysis software combined with pulmonary function test (PFT) was used to retrospectively evaluate the postoperative efficacy of BLVR patients. The purpose is to evaluate the improvement of lung function of local lung tissue after operation, maximize the benefits of patients, and facilitate BLVR in the treatment of patients with advanced COPD. All the reported cases of advanced COPD patients treated with BLVR with one-way valve were collected and analysed from 2017 to 2020. Three-dimensional-CT image analysis software system was used to analyse the distribution of low-density areas <950 Hounsfield units in both lungs pre- and post- BLVR. Meanwhile, all patients performed standard PFT pre- and post-operation for retrospective analysis. We reported six patients that underwent unilateral BLVR with 1 to 3 valves according to the range of emphysema. All patients showed a median increase in forced expiratory volume in 1 second (FEV1) of 34%, compared with baseline values. Hyperinflation was reduced by 16.6% (range, 4.9%-47.2%). The volumetric measurements showed a significant reduction in the treated lobe volume among these patients. Meanwhile, the targeted lobe volume changes were inversely correlated with change in FEV1/FEV1% in patients with heterogeneous emphysematous. We confirm that 3D-CT analysis can quantify the changes of lung volume, ventilation and perfusion, to accurately evaluate the distribution and improvement of emphysema and rely less on the observer.

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.

Pre-operative optimisation for chronic obstructive pulmonary disease: a narrative review

Chronic obstructive pulmonary disease is a condition commonly present in older people undergoing surgery and confers an increased risk of postoperative complications and mortality. Although predominantly a respiratory disease, it frequently has extra-pulmonary manifestations and typically occurs in the context of other long-term conditions. Patients experience a range of symptoms that affect their quality of life, functional ability and clinical outcomes. In this review, we discuss the evidence for techniques to optimise the care of people with chronic obstructive pulmonary disease in the peri-operative period, and address potential new interventions to improve outcomes. The article centres on pulmonary rehabilitation, widely available for the treatment of stable chronic obstructive pulmonary disease, but less often used in a peri-operative setting. Current evidence is largely at high risk of bias, however. Before surgery it is important to ensure that what have been called the 'five fundamentals' of chronic obstructive pulmonary disease treatment are achieved: smoking cessation; pulmonary rehabilitation; vaccination; self-management; and identification and optimisation of co-morbidities. Pharmacological treatment should also be optimised, and some patients may benefit from lung volume reduction surgery. Psychological and behavioural factors are important, but are currently poorly understood in the peri-operative period. Considerations of the risk and benefits of delaying surgery to ensure the recommended measures are delivered depends on patient characteristics and the nature and urgency of the planned intervention.

Endobronchial coils in treatment of advanced emphysema: A single center experience

Background

This study aims to present our experience with endobronchial coils in patients who underwent endobronchial lung volume reduction due to advanced emphysema.

Methods

The study included 46 patients (45 males, 1 female; mean age 61.7±8 years; range, 43 to 80 years) who underwent endobronchial lung volume reduction with endobronchial coils for advanced emphysema. Patients" age, gender, pulmonary function tests, post-treatment morbidity, mortality, pre- and post-treatment (6 months) six-minute walking distance, modified Medical Research Council dyspnea scores, chronic obstructive pulmonary disease assessment test and Hospital Anxiety and Depression Scale scores were recorded.

Results

Patients had an average of 65 pack/year smoking history. An average of 11 (range, 9-15) coils were placed per lobe (right upper lobe=35, left upper lobe=19, right lower lobe=2, left lower lobe=4). Mean follow-up duration was 12.6 months (±5.6 months). Post-treatment forced expiratory volume in one second, residual volume and six-minute walking distance values were improved with statistical significance. Also, significant improvement was seen in quality of life, quantified by modified Medical Research Council, chronic obstructive pulmonary disease assessment test and Hospital Anxiety and Depression Scale scores. While no immediate major postoperative complications occurred, three patients developed chronic obstructive pulmonary disease exacerbation, two developed pneumonia, and one developed recurrence of previous neurologic disorder within 30 days.

Conclusion

Endobronchial coil administration provides lower morbidity and mortality compared to lung volume reduction surgery as well as significant improvement in pulmonary functions and quality of life in selected patients with advanced emphysema.

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.

CELEB trial: Comparative Effectiveness of Lung volume reduction surgery for Emphysema and Bronchoscopic lung volume reduction with valve placement: a protocol for a randomised controlled trial

INTRODUCTION

Although lung volume reduction surgery and bronchoscopic lung volume reduction with endobronchial valves have both been shown to improve lung function, exercise capacity and quality of life in appropriately selected patients with emphysema, there are no direct comparison data between the two procedures to inform clinical decision-making.

METHODS AND ANALYSIS

We describe the protocol of the CELEB study, a randomised controlled trial which will compare outcomes at 1 year between the two procedures, using a composite disease severity measure, the iBODE score, which includes body mass index, airflow obstruction, dyspnoeaand exercise capacity (incremental shuttle walk test).

ETHICS AND DISSEMINATION

Ethical approval to conduct the study has been obtained from the Fulham Research Ethics Committee, London (16/LO/0286). The outcome of this trial will provide information to guide treatment choices in this population and will be presented at national and international meetings and published in peer-reviewed journals. We will also disseminate the main results to all participants in a letter.

TRIAL REGISTRATION NUMBER

ISRCTN19684749; Pre-results.

The safety and efficacy of endobronchialvalve therapy in patients with advanced heterogeneous emphysema versus standard medical care: A meta-analysis

BACKGROUND

Endobronchial valves had been utilized for many years to treat patients with advanced emphysema, despite unfavorable results. In this meta-analysis, we aimed to assess the efficacy and safety of the use of endobronchial valves in patients with heterogeneous advanced emphysema.

METHODS

We performed systematic database searches to identify clinical trials that met all our inclusion criteria. Direct-comparison and mixed-treatment-comparison (MTC) meta-analyses were conducted to estimate the mean difference or odds ratio of outcomes. Each outcome was analyzed with Review Manager 5 statistical software.

RESULTS

Eight prospective clinical trials assessing this therapy were retrieved, with a total of 744 patients. Outcomes, including the forced expiratory volume in 1 second (FEV1), 6-minute walk test (6MWT), and St. George's Respiratory Questionnaire (SGRQ), were analyzed, and the odds ratio of reported complications related to endobronchial valve therapy was calculated. Significant improvement in the mean difference of FEV1 (5.61 [4.42, 6.80]), 6MWT (25.75 [12.30, 39.20]), and SGRQ (-10.96 [-13.88, -8.05]) was observed after endobronchial valve treatment. Moreover, the rate of adverse events related to endobronchial valves was low.

CONCLUSIONS

Endobronchial valve treatment offers benefits in terms of lung function and quality of life. Endobronchial valve treatment is feasible and safe for patients with advanced heterogeneous emphysema, especially those with no evidence of collateral ventilation.

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.

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 accuracy of computed tomography to predict completeness of pulmonary fissures. A prospective study

RATIONALE

Endobronchial valves are a potential alternative to lung volume reduction surgery for advanced emphysema. The greatest improvements in pulmonary function are seen in patients with complete pulmonary fissures, as determined by computed tomography (CT). However, the accuracy of CT to predict completeness of pulmonary fissures has not been compared with the reference standard of direct observation during thoracic surgery.

OBJECTIVES

To determine the accuracy of CT scans to predict completeness of pulmonary fissures.

METHODS

We conducted a double-blind, prospective trial in which completeness of pulmonary fissures was evaluated by direct observation during thoracic surgery. Preoperative CT scans were independently reviewed by two dedicated thoracic radiologists and completeness of the fissures was recorded and compared with intraoperative findings.

MEASUREMENTS AND MAIN RESULTS

The fissures of 46 patients were evaluated. The positive predictive value of CT scan to detect a complete fissure was 100% for the right major fissure and 75% for the left fissure, but only 33% for the right minor fissure. CT scans had a negative predictive value of 29% in evaluation of the right major fissure.

CONCLUSIONS

CT scans overestimate completeness of the right minor fissure and underestimate completeness of the right major fissure. These findings may have implications for the use of CT scans to select patients for endobronchial valve insertion.

Efficacy and safety of endobronchial valves for advanced emphysema: a meta analysis

OBJECTIVE

A meta-analysis was undertaken to evaluate the efficacy and safety of bronchoscopic lung volume reduction with endobronchial valves (EBV) for advanced emphysema.

METHODS

A systematic search was performed from PubMed, EMBASE, CNKI, Cochrane Library database. Randomized control clinical trials on treatment of emphysema for 3-12 months with the EBV compared with standard medications and sham EBV were reviewed. Inclusion criteria were applied to select patients with advanced emphysema treated with EBV. The primary outcome was the percentage of the forced expiratory volume in the first second (FEV1%). Secondary outcomes included St George's Respiratory Questionnaire (SGRQ) score, the distance of the 6-minute walk (6MWD) test, the Modified Medical Research Council (MMRC) dyspnoea score, cycle ergometry workload, and the rate of the six major complications at 3 or 12 months. Fixed- or random-effects models were used and weighted mean differences (WMD), relative risks (RR) and 95% confidence intervals (CI) were calculated.

RESULTS

Three trials (565 patients) were considered in the meta-analysis. EBV patients yielded greater increases in FEV1% than standard medications (WMD =6.71; 95% CI, 3.31 to 10.10; P=0.0001), EBV patients also demonstrated a significant change for SGRQ score (WMD =-3.64; 95% CI, -5.93 to -1.34; P=0.002), MMRC dyspnoea score (WMD =-0.26; 95% CI, -0.44 to -0.08; P=0.004), and cycle ergometry workload (WMD =4.18; 95% CI, 2.14 to 6.22; P<0.0001). A similar level was evident for 6MWD (WMD =11.66; 95% CI, -3.31 to 26.64; P=0.13). EBV may increase the rate of hemoptysis (RR =5.15; 95% CI, 1.16 to 22.86; P=0.03), but didn't increase the adverse events including mortality, respiratory failure, empyema, pneumonia, pneumothrax. The overall rates for complications compared EBV with standard medications and sham EBV was not significant (RR =2.03; 95% CI, 0.98 to 4.21; P=0.06).

CONCLUSIONS

EBV lung volume reduction for advanced emphysema showed superior efficacy and a good safety and tolerability compared with standard medications and sham EBV, further more randomized controlled trial (RCT) studies are needed to pay more attention to the long-term efficacy and safety of bronchoscopic lung volume reduction with EBV in advanced emphysema.

Effectiveness of bronchoscopic lung volume reduction using unilateral endobronchial valve: a systematic review and meta-analysis

BACKGROUND

Bronchoscopic lung volume reduction (BLVR) can be suggested as an alternative for surgical lung volume reduction surgery for severe emphysema patients. This article intends to evaluate by systematic review the safety and effectiveness of BLVR using a one-way endobronchial valve.

METHODS

A systematic search of electronic databases, including MEDLINE, EMBASE, and the Cochrane Library, as well as eight domestic databases up to December 2013, was performed. Two reviewers independently screened all references according to selection criteria. The Scottish Intercollegiate Guidelines Network criterion was used to assess quality of literature. Data from randomized controlled trials were combined and meta-analysis was performed.

RESULTS

This review included 15 studies. Forced expiratory volume in 1 second (FEV1) improved in the intervention group compared with the control group (mean difference [MD]=6.71, 95% confidence interval [CI]: 3.31-10.11). Six-minute walking distance (MD=15.66, 95% CI: 1.69-29.64) and cycle workload (MD=4.43, 95% CI: 1.80-7.07) also improved. In addition, St George's Respiratory Questionnaire score decreased (MD=4.29, 95% CI: -6.87 to -1.71) in the intervention group. In a subgroup analysis of patients with complete fissure, the FEV1 change from baseline was higher in the BLVR group than in the control group for both 6 months (MD=15.28, P<0.001) and 12 months (MD=17.65, P<0.001), whereas for patients with incomplete fissure, FEV1 and 6-minute walking distance showed no change. One-year follow-up randomized controlled trials reported deaths, although the cause of death was not related to BLVR. Respiratory failure and pneumothorax incidence rates were relatively higher in the BLVR group, but the difference was not significant.

CONCLUSION

BLVR may be an effective and safe procedure for the treatment of severe COPD patients with emphysema, based on existing studies.

Bronchoscopic interventions for severe COPD

Chronic obstructive pulmonary disease (COPD) causes severe handicap among smokers. Most patients have to remain under continuous oxygen therapy at home. Moreover, respiratory infections are very common among these patients and vaccination is obligatory against influenza. Emphysema and bronchiectasis are observed with computed tomography (CT) and in several situations these parenchymal damages are responsible for pneumothorax in one case and pseudomonas aeroginosa infection. Novel mini-invasive techniques are used currently for emphysema treatments which are described extensively throughout our current work.

Endoscopic lung volume reduction. An American perspective

There are limited therapies for severe emphysema. Bronchoscopic treatments of emphysema were introduced to achieve the beneficial physiological changes seen in surgical lung volume reduction; however, at the present time these treatments are mostly aimed at improving quality of life and functional status in patients with emphysema. At this time, none of these minimally invasive approaches have been approved in the United States for treatment of emphysema; however, several novel interventions have demonstrated potential in early-phase clinical trials. We performed a systematic evaluation of the relevant medical literature and present herein an evidence-based review of bronchoscopic treatments for emphysema, with a focus on the current status of this technology in the United States as compared with Europe.

Assessment of the relationship between morphological emphysema phenotype and corresponding pulmonary perfusion pattern on a segmental level

PURPOSE

Distinct morphological emphysema phenotypes were assessed by CT to show characteristic perfusion defect patterns.

MATERIAL/METHODS

Forty-one patients with severe emphysema (GOLD III/IV) underwent three-dimensional high resolution computed tomography (3D-HRCT) and contrast-enhanced magnetic resonance (MR) perfusion. 3D-HRCT data was visually analyzed for emphysema phenotyping and quantification by consensus of three experts in chest-radiology. The predominant phenotype per segment was categorized as normal, centrilobular, panlobular or paraseptal. Segmental lung perfusion was visually analyzed using six patterns of pulmonary perfusion (1-normal; 2-mild homogeneous reduction in perfusion; 3-heterogeneous perfusion without focal defects; 4-heterogeneous perfusion with focal defects; 5-heterogeneous absence of perfusion; 6-homogeneous absence of perfusion), with the extent of the defect given as a percentage.

RESULTS

730 segments were evaluated. CT categorized 566 (78%) as centrilobular, 159 (22%) as panlobular and 5 (<1%) as paraseptal with no normals. Scores with regards to MR perfusion patterns were: 1-0; 2-0; 3-28 (4%); 4-425 (58%); 5-169 (23%); 6-108 (15%). The predominant perfusion pattern matched as follows: 70 % centrilobular emphysema - heterogeneous perfusion with focal defects (score 4); 42% panlobular--homogeneous absence of perfusion (score 5); and 43% panlobular--heterogeneous absence of perfusion (score 6).

CONCLUSION

MR pulmonary perfusion patterns correlate with the CT phenotype at a segmental level in patients with severe emphysema.

KEY POINTS

• MR perfusion patterns correlate with the CT phenotype in emphysema. • Reduction of MR perfusion is associated with loss of lung parenchyma on CT • Centrilobular emphysema shows heterogeneous perfusion reduction while panlobular emphysema shows loss of perfusion.

Efficacy of bronchoscopic lung volume reduction: a meta-analysis

Background

Over the last several years, the morbidity, mortality, and high costs associated with lung volume reduction (LVR) surgery has fuelled the development of different methods for bronchoscopic LVR (BLVR) in patients with emphysema. In this meta-analysis, we sought to study and compare the efficacy of most of these methods.

Methods

Eligible studies were retrieved from PubMed and Embase for the following BLVR methods: one-way valves, sealants (BioLVR), LVR coils, airway bypass stents, and bronchial thermal vapor ablation. Primary study outcomes included the mean change post-intervention in the lung function tests, the 6-minute walk distance, and the St George’s Respiratory Questionnaire. Secondary outcomes included treatment-related complications.

Results

Except for the airway bypass stents, all other methods of BLVR showed efficacy in primary outcomes. However, in comparison, the BioLVR method showed the most significant findings and was the least associated with major treatment-related complications. For the BioLVR method, the mean change in forced expiratory volume (in first second) was 0.18 L (95% confidence interval [CI]: 0.09 to 0.26; P<0.001); in 6-minute walk distance was 23.98 m (95% CI: 12.08 to 35.88; P<0.01); and in St George’s Respiratory Questionnaire was -8.88 points (95% CI: −12.12 to −5.64; P<0.001).

Conclusion

The preliminary findings of our meta-analysis signify the importance of most methods of BLVR. The magnitude of the effect on selected primary outcomes shows noninfe-riority, if not equivalence, when compared to what is known for surgical LVR.

Defeating the pores of Kohn

In the treatment of emphysema with an endobronchial valve, entire lobar treatment is important in achieving adequate atelectasis. This case illustrates that without treatment of the entire lobe, it can fail to collapse even after several years, leading to treatment failure. Intralobar collateral ventilation through the pores of Kohn is demonstrated in this case, as endobronchial valve blockage of the remaining patent anterior segment resulted in the desired atelectasis and significant improvements in pulmonary function.

Hyperpolarized 3He functional magnetic resonance imaging of bronchoscopic airway bypass in chronic obstructive pulmonary disease

A 73-year-old exsmoker with Global initiative for chronic Obstructive Lung Disease stage III chronic obstructive pulmonary disease underwent airway bypass (AB) as part of the Exhale Airway Stents for Emphysema (EASE) trial, and was the only EASE subject to undergo hyperpolarized 3He magnetic resonance imaging for evaluation of lung function pre- and post-AB. 3He magnetic resonance imaging was acquired twice previously (32 and eight months pre-AB) and twice post-AB (six and 12 months post-AB). Six months post-AB, his increase in forced vital capacity was <12% predicted, and he was classified as an AB nonresponder. However, post-AB, he also demonstrated improvements in quality of life scores, 6 min walk distance and improvements in 3He gas distribution in the regions of stent placement. Given the complex relationship between well-established pulmonary function and quality of life measurements, the present case provides evidence of the value-added information functional imaging may provide in chronic obstructive pulmonary disease interventional studies.

A review of current bronchoscopic interventions for obstructive airway diseases

Obstructive diseases of the airway are a diverse group, although they share in common airway narrowing as a sequel to inflammation, which leads to increased work of breathing. Optimal treatment strategies for this heterogeneous group of asthma, chronic bronchitis and emphysema should be multidimensional and embrace pharmacological and nonpharmacological means as well as surgery in a highly select group of patients with emphysema. We review the current status of the bronchoscopic interventions that have been in development for the past decade with the objectives of providing better symptom control in asthma and palliation in individuals with emphysema who are otherwise poor candidates for lung volume reduction surgery.

[Tracheobronchomalacia in adults: breakthroughs and controversies]

Tracheobronchomalacia (TBM) in adults is a disease defined by a reduction of more than 50% of the airway lumen during expiration. It encompasses many etiologies that differ in their morphologic aspects, pathophysiological mechanisms and histopathologies. TBM is encountered with increasing frequency, as it is more easily diagnosed with new imaging techniques and diagnostic bronchoscopy, as well as because of its frequent association with Chronic Obstructive Pulmonary Disease (COPD), which represents the most frequent etiology for acquired TBM in adults. A distinction between TBM in association with failure of the cartilaginous part of the airways and TBM affecting only the posterior membranous part is emerging since their physiopathology and treatment differ. The therapeutic management of TBM should be as conservative as possible. Priority should be given to identification and treatment of associated respiratory diseases, such as asthma or COPD. Surgery addressing extrinsic compression (thyroid goiter or tumor, for example) may be necessary. Noninvasive ventilation can be considered in patients with increasing symptoms. Endoscopic options, such as the placement of stents, should only be used as palliative or temporary solutions, because of the high complication rates. Symptomatic improvement after stenting might be helpful in selecting patients in whom a surgical management with tracheobronchoplasty can be useful.

Lung cancer following bronchoscopic lung volume reduction for severe emphysema: a case and its management

Bronchoscopic lung volume reduction using endobronchial valves has been suggested as a potentially safer alternative to surgery in selected cases. Complications of this technique include pneumothoraces, pneumonia, COPD exacerbations, hemoptysis, and valve migrations. We report the case of a male patient who developed a parenchymal mass in the treated lobe after valve insertion. Due to severe emphysema, transthoracic needle aspiration was not feasible. Removal of the valves was mandatory to perform transbronchialbiopsies which revealed a non-small cell primary lung cancer. This first description illustrates the potential risk of lung cancer development following bronchoscopic lung volume reduction and highlights the different approach to diagnosis and management of indeterminate peripheral lung lesions needed in this context.

Lung transplantation and lung volume reduction surgery

Since the publication of the last edition of the Handbook of Physiology, lung transplantation has become widely available, via specialized centers, for a variety of end-stage lung diseases. Lung volume reduction surgery, a procedure for emphysema first conceptualized in the 1950s, electrified the pulmonary medicine community when it was rediscovered in the 1990s. In parallel with their technical and clinical refinement, extensive investigation has explored the unique physiology of these procedures. In the case of lung transplantation, relevant issues include the discrepant mechanical function of the donor lungs and recipient thorax, the effects of surgical denervation, acute and chronic rejection, respiratory, chest wall, and limb muscle function, and response to exercise. For lung volume reduction surgery, there have been new insights into the counterintuitive observation that lung function in severe emphysema can be improved by resecting the most diseased portions of the lungs. For both procedures, insights from physiology have fed back to clinicians to refine patient selection and to scientists to design clinical trials. This section will first provide an overview of the clinical aspects of these procedures, including patient selection, surgical techniques, complications, and outcomes. It then reviews the extensive data on lung and muscle function following transplantation and its complications. Finally, it reviews the insights from the last 15 years on the mechanisms whereby removal of lung from an emphysema patient can improve the function of the lung left behind.

Treatment of advanced emphysema with emphysematous lung sealant (AeriSeal®)

BACKGROUND

This report summarizes initial tests of an emphysematous lung synthetic polymer sealant (ELS) designed to reduce lung volume in patients with advanced emphysema.

OBJECTIVES

The primary study objective was to define a therapeutic strategy to optimize treatment safety and effectiveness.

METHODS

ELS therapy was administered bronchoscopically to 25 patients with heterogeneous emphysema in an open-label, noncontrolled study at 6 centers in Germany. Treatment was performed initially at 2-4 subsegments. After 12 weeks, patients were eligible for repeat therapy to a total of 6 sites. Safety and efficacy were assessed after 6 months. Responses were evaluated in terms of changes from baseline in lung physiology, functional capacity, and health-related quality of life. Follow-up is available for 21 of 25 patients.

RESULTS

Treatment was well tolerated. There were no treatment-related deaths (i.e., within 90 days of treatment), and an acceptable short- and long-term safety profile. Physiological and clinical benefits were observed at 24 weeks. Efficacy responses were better among Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage III patients [n = 14; change in residual volume/total lung capacity (ΔRV/TLC) = -7.4 ± 10.3%; Δ forced expiratory volume in 1 s (ΔFEV(1)) = +15.9 ± 22.6%; change in forced vital capacity (ΔFVC) = +24.1 ± 22.7%; change in carbon monoxide lung diffusion capacity (ΔDLCO) = +19.3 ± 34.8%; change in 6-min walk test (Δ6MWD) = +28.7 ± 59.6 m; change in Medical Research Council Dyspnea (ΔMRCD) score = -1.0 ± 1.04 units; change in St. George's Respiratory Questionnaire (ΔSGRQ) score = -9.9 ± 15.3 units] than for GOLD stage IV patients (n = 7; ΔRV/TLC = -0.5 ± 6.4%; ΔFEV(1) = +2.3 ± 12.3%; ΔFVC = +2.6 ± 21.1%; ΔDLCO = -2.8 ± 17.2%; Δ6MWD = +28.3 ± 58.4 m; ΔMRCD = 0.3 ± 0.81 units; ΔSGRQ = -6.7 ± 7.0 units).

CONCLUSIONS

ELS therapy shows promise for treating patients with advanced heterogeneous emphysema. Additional studies to assess responses in a larger cohort with a longer follow-up are warranted.

Bronchoscopic lung volume reduction

The application of lung volume reduction surgery in clinical practice is limited by high postoperative morbidity and stringent selection criteria. This has been the impetus for the development of bronchoscopic approaches to lung volume reduction. A range of different techniques such as endobronchial blockers, airway bypass, endobronchial valves, thermal vapor ablation, biological sealants, and airway implants have been employed on both homogeneous as well as heterogeneous emphysema. The currently available data on efficacy of bronchoscopic lung volume reduction are not conclusive and subjective benefit in dyspnoea scores is a more frequent finding than improvements on spirometry or exercise tolerance. Safety data are more promising with rare procedure-related mortality, few serious complications, and short hospital length of stay. The field of bronchoscopic lung volume reduction continues to evolve as ongoing prospective randomized trials build on earlier feasibility data to clarify the true efficacy of such techniques.

Lung volume reduction therapies for advanced emphysema: an update

Observational and randomized studies provide convincing evidence that lung volume reduction surgery (LVRS) improves symptoms, lung function, exercise tolerance, and life span in well-defined subsets of patients with emphysema. Yet, in the face of an estimated 3 million patients with emphysema in the United States, < 15 LVRS operations are performed monthly under the aegis of Medicare, in part because of misleading reporting in lay and medical publications suggesting that the operation is associated with prohibitive risks and offers minimal benefits. Thus, a treatment with proven potential for palliating and prolonging life may be underutilized. In an attempt to lower risks and cost, several bronchoscopic strategies (bronchoscopic emphysema treatment [BET]) to reduce lung volume have been introduced. The following three methods have been tested in some depth: (1) unidirectional valves that allow exit but bar entry of gas to collapse targeted hyperinflated portions of the lung and reduce overall volume; (2) biologic lung volume reduction (BioLVR) that involves intrabronchial administration of a biocompatible complex to collapse, inflame, scar, and shrink the targeted emphysematous lung; and (3) airway bypass tract (ABT) or creation of stented nonanatomic pathways between hyperinflated pulmonary parenchyma and bronchial tree to decompress and reduce the volume of oversized lung. The results of pilot and randomized pivotal clinical trials suggest that the bronchoscopic strategies are associated with lower mortality and morbidity but are also less efficient than LVRS. Most bronchoscopic approaches improve quality-of-life measures without supportive physiologic or exercise tolerance benefits. Although there is promise of limited therapeutic influence, the available information is not sufficient to recommend use of bronchoscopic strategies for treating emphysema.

Effect of unilateral endobronchial valve insertion on pulmonary ventilation and perfusion: a pilot study

BACKGROUND AND OBJECTIVE

The effects of bronchoscopic lung volume reduction (BLVR) on pulmonary ventilation and perfusion are incompletely understood. In this pilot trial, we investigated serial changes in regional ventilation and perfusion following unilateral endobronchial valve placement in COPD patients with heterogeneous emphysema.

METHODS

At baseline and at days 30 and 90 following BLVR, subjects underwent lung function, 6MWD and St George's Respiratory Questionnaire. Ventilation and perfusion scintigraphy were performed to quantitate and serially compare regional differences.

RESULTS

Six out of eight subjects completed the study; all had endobronchial valves targeting their left upper lobe. At day 90 post-BLVR, there was a trend towards an increase in FEV(1) and a mean reduction in St George's Respiratory Questionnaire score of nine units. In the targeted left upper zone there was reduced ventilation and perfusion. Ventilation and perfusion to the right lung; and specifically the right lower zone, significantly increased.

CONCLUSIONS

There appears to be redistribution of ventilation and perfusion to the contralateral lung following endobronchial valve placement. This may be of importance when assessing patients for unilateral BLVR. Selecting patients with heterogeneous disease is emphasized, taking into consideration not just comparison between upper and lower lobes, but between left and right lungs. A larger trial is currently underway, guided by these findings.

Bronchoscopic lung volume reduction with a dedicated coil: a clinical pilot study

BACKGROUND

Lung volume reduction aims to improve symptoms by reducing hyperinflation. Endoscopic approaches so far have generally been hampered in their efficacy by collateral ventilation (CV). We sought to determine the safety and feasibility of a new endoscopic lung volume reduction approach independent of the effects of CV.

METHODS

Patients with severe emphysema were eligible. Inclusion and exclusion criteria were modeled after the National Emphysema Treatment Trial (NETT) study. Homogenous and heterogeneous disease was allowed. Treatment consisted of the placement of coils into the parenchyma of the most diseased area with the intent of achieving parenchymal compression. Primary endpoints were safety and feasibility assessments. Secondary endpoints were efficacy outcomes.

RESULTS

Eleven patients underwent 21 procedures. Procedures were performed under general anesthesia and lasted 45+/-15 minutes and per procedure 4.9+/-0.6 coils were placed. All procedures were well tolerated. The total follow-up time was 7-11 months and in that time 33 adverse events were reported, none of them severe. No pneumothorax occurred. Efficacy seemed better in heterogeneous rather than homogenous disease.

CONCLUSION

Endoscopic lung volume reduction with coils is safe and feasible. Further studies of the efficacy are indicated.

Endoscopic management of emphysema

Lung volume reduction surgery has proven benefits in emphysema. However, high postoperative morbidity and stringent selection criteria for suitable candidates are limitations in clinical practice. Endoscopic approaches to lung volume reduction have used a range of different techniques such as endobronchial blockers, airway bypass, endobronchial valves, biologic sealants, and airway implants to address the limitations of surgery. The underlying physiologic mechanisms of endoscopic modalities vary, and homogeneous and heterogeneous emphysema are targeted. Currently available data on efficacy of bronchoscopic lung volume reduction are not consistently conclusive, and subjective benefit in dyspnea scores is a more frequent finding than improvements on spirometry or exercise tolerance. The safety data are more promising, with rare procedure-related mortality, fewer complications than lung volume reduction surgery, and short hospital length of stay. The field of bronchoscopic lung volume reduction continues to evolve as ongoing prospective randomized trials aim to clarify the efficacy data from earlier feasibility and safety studies.

Taking a chance: the experience of lung volume reduction procedures for chronic obstructive pulmonary disease

OBJECTIVES

Lung Volume Reduction Surgery and Endo-Bronchial Valve(TM) insertion have expanded the therapeutic choices for chronic obstructive pulmonary disease (COPD). Controversy over efficacy, costs and risks limits access to these therapies. There are no published findings to guide our understanding of the patient's experience of surgery. The aim of this study is to understand the experience of palliative surgery for COPD.

METHODS

Merleau-Ponty's philosophy provided a framework for this Heideggerian phenomenological inquiry. Fifty-eight semi-structured interviews were conducted with 15 patients undergoing lung volume reduction procedures and 14 family members.

RESULTS

Patients and families felt they had no option but to 'take a chance' on surgery. Interventions frequently led to regaining lost tasks or easier completion of existing tasks. Where patients did not perceive an increase in things they could 'do', surgery allowed some to reclaim their sense of self. Regardless of the outcome, most did not regret their decision for surgery.

DISCUSSION

Meanings of surgery are not always tied to the visible, objective measurements of outsiders but may relate to regaining of self. Despite the concerns of some clinicians, patients and families are more likely to accept the risk of morbidity and mortality from surgery than has previously been realized.

Update on radiology of emphysema and therapeutic implications

Emerging treatments require appropriate CT targeting of a selected lobe or lobes and target airways to obtain a successful response. CT scan is used in pretreatment planning to select patients and plan treatment strategy and posttreatment to confirm correct deployment of devices and assess treatment response. Increasingly treatments are being developed to treat patients who have emphysema who require accurate quantitation of extent and distribution of the process. Functional assessment can be made by inference of detailed anatomic correlates and by direct measurement of regional function using dynamic scan protocols. This article summarizes the current role of imaging in the assessment of patients who have emphysema.

Treatment of heterogeneous emphysema using the spiration IBV valves

Ninety-eight emphysema patients were treated at 13 international sites during a 3-year series of single-arm, open-label studies with the IBV valve and a multi-lobar treatment approach. Fifty six percent of subjects had a clinically meaningful improvement in health-related quality of life, but standard pulmonary function and exercise studies were insensitive effectiveness measures. Quantitative CT analyses of regional lung changes showed lobar volume changes in over 85% of subjects. Lung volume reduction was an uncommon mechanism for a treatment response with bilateral upper lobe treatment. A redirection of inspired air, an interlobar shift to health-ier lung tissue, was the most common mechanism for a valve treatment response.

Computer-aided detection of endobronchial valves using volumetric CT

RATIONALE AND OBJECTIVES

The ability to automatically detect and monitor implanted devices may serve an important role in patient care by aiding the evaluation of device and treatment efficacy. The purpose of this research was to develop a system for the automated detection of one-way endobronchial valves that were implanted for less invasive lung volume reduction.

MATERIALS AND METHODS

Volumetric thin-section computed tomographic data was obtained for 194 subjects; 95 subjects implanted with 246 devices were used for system development and 99 subjects implanted with 354 devices were reserved for testing. The detection process consisted of preprocessing, pattern recognition based detection, and a final device selection. Following the preprocessing, a set of classifiers was trained using AdaBoost to discriminate true devices from false positives. The classifiers in the cascade used two simple features (either the mean or maximum attenuation) of a local region computed at multiple fixed landmarks relative to a template model of the valve.

RESULTS

Free-response receiver-operating characteristic analysis was performed for the evaluation; the system could be set so the mean sensitivity was 96.5% with a mean of 0.18 false positives per subject. If knowledge of the number of implanted devices were incorporated, the sensitivity would be 96.9% with a mean of 0.061 false positives per subject; this corresponds to a total of 12 false negatives and six false positives for the 99 subjects in the test dataset.

CONCLUSION

Software was developed for automated detection of endobronchial valves on volumetric computed tomography. The proposed device modeling and detection techniques may be applicable to other devices as well as useful for evaluation of treatment response.

Biologic lung volume reduction in advanced upper lobe emphysema: phase 2 results

RATIONALE

Biologic lung volume reduction (BioLVR) is a new endobronchial treatment for advanced emphysema that reduces lung volume through tissue remodeling.

OBJECTIVES

Assess the safety and therapeutic dose of BioLVR hydrogel in upper lobe predominant emphysema.

METHODS

Open-labeled, multicenter phase 2 dose-ranging studies were performed with BioLVR hydrogel administered to eight subsegmental sites (four in each upper lobe) involving: (1) low-dose treatment (n = 28) with 10 ml per site (LD); and (2) high-dose treatment (n = 22) with 20 ml per site (HD). Safety was assessed by the incidence of serious medical complications. Efficacy was assessed by change from baseline in pulmonary function tests, dyspnea score, 6-minute walk distance, and health-related quality of life.

MEASUREMENTS AND MAIN RESULTS

After treatment there were no deaths and four serious treatment-related complications. A reduction in residual volume to TLC ratio at 12 weeks (primary efficacy outcome) was achieved with both LD (-6.4 +/- 9.3%; P = 0.002) and HD (-5.5 +/- 9.4%; P = 0.028) treatments. Improvements in pulmonary function in HD (6 mo: DeltaFEV(1) = +15.6%; P = 0.002; DeltaFVC = +9.1%; P = 0.034) were greater than in LD patients (6 mo: DeltaFEV(1) = +6.7%; P = 0.021; DeltaFVC = +5.1%; P = 0.139). LD- and HD-treated groups both demonstrated improved symptom scores and health-related quality of life.

CONCLUSIONS

BioLVR improves physiology and functional outcomes up to 6 months with an acceptable safety profile in upper lobe predominant emphysema. Overall improvement was greater and responses more durable with 20 ml per site than 10 ml per site dosing. Clinical trial registered with www.clinicaltrials.gov (NCT 00435253 and NCT 00515164).

Bronchoscopic lung volume reduction in severe emphysema

Lung volume reduction surgery (LVRS) produces physiological, symptomatic, and survival benefits in selected patients with advanced emphysema. Because it is associated with significant morbidity, mortality, and cost, nonsurgical alternatives for achieving volume reduction have been developed. Three bronchoscopic lung volume reduction (BLVR) approaches have shown promise and reached later-stage clinical trials. These include the following: (1) placement of endobronchial one-way valves designed to promote atelectasis by blocking inspiratory flow; (2) formation of airway bypass tracts using a radiofrequency catheter designed to facilitate emptying of damaged lung regions with long expiratory times; and (3) instillation of biological adhesives designed to collapse and remodel hyperinflated lung. The limited clinical data currently available suggest that all three techniques are reasonably safe. However, efficacy signals have been substantially smaller and less durable than those observed after LVRS. Studies to optimize patient selection, refine treatment strategies, characterize procedural safety, elucidate mechanisms of action, and characterize short- and longer-term effectiveness of these approaches are ongoing. Results will be available over the next few years and will determine whether BLVR represents a safe and effective alternative to LVRS.

Bronchoscopic approach to COPD

Chronic obstructive pulmonary disease (COPD) is a highly prevalent condition that has frequent morbidity and mortality, with associated costs of US $ 2.5 billion annually and nearly 14,000 deaths each year. In the most advanced stages it causes debilitating breathlessness which is not improved despite maximal medical therapy including smoking cessation, bronchodilators, steroids and supplemental oxygen. Limitations of medical therapy led to the development of several surgical techniques to improve quality of life. However, surgical techniques still carry substantial morbidity even if the mortality is low at centers with larger experience; hence investigators are vigorously pursuing research into innovative, alternative methods for achieving lung volume reduction (LVR), in recent years. Endoscopic techniques for LVR are proposed, based on two main approaches, either closing of anatomical airway passages into destroyed lobe/segment of the lung to affect a collapse and reduction in volume or opening extra-anatomical airway passages, aimed at improving expiratory collateral flow from hyper-inflated areas bypassing the flow limited segments of the emphysematous airways. This article reviews the available endoscopic devises and the evidence supporting their use in the treatment of COPD.

Evolving endoscopic approaches for treatment of emphysema

Novel endobronchial methods for reducing lung volume in patients with advanced emphysema are currently being evaluated in clinical trials as potential alternatives to lung volume reduction surgery (LVRS). Three bronchoscopic lung volume reduction (BLVR) approaches have shown promise in initial testing: (1) placement of endobronchial one-way valves to promote atelectasis by blocking inspiratory flow; (2) airway bypass tract formation using a radiofrequency catheter to facilitate emptying of damaged lung regions with long expiratory times; and (3) instillation of biological adhesives designed to collapse and remodel hyperinflated lung. The limited clinical data currently available suggests all three techniques are reasonably safe. However, efficacy signals have been smaller and less durable than those observed after LVRS. Studies to optimize patient selection, refine treatment strategies, characterize procedural safety, elucidate mechanisms of action, and characterize short- and longer-term effectiveness of each approach are ongoing.

State of the art: interventional pulmonology

Interventional pulmonology (IP) provides comprehensive care to patients with structural airway disorders and pleural diseases. A growing armamentarium of diagnostic and therapeutic tools has expanded the interventional pulmonologist's ability to care for pulmonary patients with complex abnormalities, often in concert and close collaboration with physicians in other specialties, such as thoracic surgery. Innovative technologies promise to have an impact on diseases and clinical entities not traditionally treated by invasive pulmonary interventions, such as asthma, COPD, and the solitary pulmonary nodule. Training, credentialing, reimbursement, and scientific validation remain key necessities for the continued growth of IP, and require a concerted effort by chest physicians and their professional organizations.