Interlobar Collateral Ventilation Research Articles

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.

Inhaled Steroids, Sex and Emphysema Index - Clinical Parameters with Impact on the Effectiveness of Valve Implantation in Patients with Severe Emphysema.

Aims and ObjectivesMany patients with chronic obstructive lung disease suffer from emphysema. Valve implantation may be a reasonable method in patients presenting advanced emphysema and absent interlobar collateral ventilation (CV). However, other clinical parameters influencing the effectiveness of endoscopic lung volume reduction (ELVR) are not well known.MethodsCOPD patients with advanced emphysema who received valve implantation in 2016 were retrospectively analyzed. The following characteristics were collected prior to valve implantation: age, sex, body mass index, presence of allergies, use of inhaled corticosteroids (ICS), lung function parameters, diffusion capacity, 6-minute walk distance (6-MWD), blood gases, COHb, smoking history, and emphysema index (quantitative multi-detector computed tomography). Three months following valve implantation, lung function parameters, diffusion capacity, 6-MWD and blood gases were measured. In this analysis, we evaluated the impact of these variables on an increase in FEV1 and 6-MWT as well as a decrease in RV three months after valve implantation.ResultsOverall, 77 COPD patients (57% male, mean age 66, mean FEV1 32%, mean RV 259%) who underwent valve therapy were enrolled. At 3-month follow-up, patients experienced a mean FEV1 increase of 0.09 ± 0.21 L, a mean RV decrease of 0.42 ± 1.80 L and a mean improvement of 8.3 ± 57 m in the 6-MWT. Overall, ICS, sex and emphysema index had an impact on the outcome following ELVR: ICS medication was associated with inferior FEV1 outcome. The higher the emphysema index, the less the RV reduction. Sex was a predictor for change of FEV1 (%), RV (L), and 6-MWT: male patients seem to benefit less than female patients from valve implantation.ConclusionThese findings suggest that ICS, emphysema index and sex are clinical parameters that may be associated with inferior outcome following ELVR. Further studies have to confirm these results to improve patient selection and clinical outcome of ELVR.

Imaging ventilation using 19F perfluorinated gas magnetic resonance imaging: strategies for imaging collateral ventilation

Collateral Ventilation (CV) has become an important clinical issue with the increasing use of bronchoscopic lung volume reduction (BLVR) using endobronchial valve surgery in patients with severe COPD. The endobronchial valve BLVR procedure often uses one way valves to occlude segmental bronchi in lung regions with severe overinflation resulting from airway narrowing and collapse during exhalation. For BLVR to succeed, CV to the treated region must be minimal or absent. Current approaches to evaluating CV for both planning and follow-up of BLVR procedures involve CT imaging to assess fissure closure. Current techniques to assess regional lung function (including CV) are limited. Standard pulmonary function testing involving analysis of inert gas wash-in/wash-out can only provide statistical distributions without anatomic correlates. Herein we propose the use of fluorine magnetic resonance imaging of biologically inert perfluorinated gas mixed with oxygen to evaluate regional ventilation, in particular, interlobar collateral ventilation. We have evaluated normal subjects and subjects diagnosed with chronic obstructive pulmonary disease and have observed gas transfer at lobar fissures consistent with collateral ventilation.

THORACOSCOPIC SURGICAL STAPLING AND ENDOBRONCHIAL VALVE PLACEMENT FOR LUNG VOLUME REDUCTION WITH INCOMPLETE LOBAR FISSURES: INITIAL EXPERIENCE

SESSION TITLE: Fellows Obstructive Lung Disease Posters SESSION TYPE: Fellow Case Report Posters PRESENTED ON: October 18-21, 2020 INTRODUCTION: Emphysema affects more than 4 million cases diagnosed in the US. Recently, bronchial valves were approved for selected patients with complete lobar fissure and severe hyperinflation. Unfortunately, most patients have collateral ventilation (CV) and thus are not candidates for bronchoscopic lung volume reduction alone. Combined minimally invasive thoracoscopic intervention to complete lung fissure along with bronchial valves (BVs) to achieve lung volume reduction is an appealing treatment for the majority of patients with CV. Our group has recently described the use of this combined procedure in animal models, but this is the first description in clinical practice. CASE PRESENTATION: A 58-year-old woman with severe heterogeneous emphysema and hyperinflation underwent endobronchial bronchial valves placement without significant improvement in her symptoms or pulmonary function tests at her 6 months follow-up visit. Following a multidisciplinary discussion with thoracic surgery, the patient underwent major fissure completion via VATS. The patient tolerated the procedure well and was discharged from the hospital on postoperative day 3. At 1-month follow up, patient-reported progressive improvement in her dyspnea. Her chest radiography showed atelectasis of the target lobe. Her lung function test showed an improvement of 0.1L (4%) in her FEV1, a decrease of 0.5L (27%) in her RV, and an increase of 1.4mL/min/mmHg (18%) in her DLCO. Another 59-year-old woman with severe homogeneous emphysema with hyperinflation. She underwent bronchial valve placement without significant improvement in her symptoms or pulmonary function tests at 12 months follow up visit. Following a multidisciplinary discussion with thoracic surgery, the patient underwent major fissure completion via VATS along with the removal of abundant pleural adhesions. She had an air leak for 3 days that resolved and was discharged home at postoperative day 4. At one month follow up, the patient had no improvement in her dyspnea. Her chest radiography showed hyperinflation without improvement in the lung function test. DISCUSSION: As emphysema remains an irreversible disease, treatment goals are primarily aimed to slow and stabilize disease progression, relieve symptoms, and improve quality of life. The most important factor that may prevent the development of desired lung volume reduction following bronchial valve treatment is CV. We present the first 2 cases in which a thoracoscopic approach was used to complete the interlobar fissures to address CV. The refinement of the technique along with appropriate patient selection is still under progress. CONCLUSIONS: Lobar fissure completion along with bronchial valves is a promising management alternative for patients with CV. Reference #1: Majid A, Kheir F, Alape D, Chee A, Parikh M, DeVore L, et al. Combined Thoracoscopic Surgical Stapling and Endobronchial Valve Placement For Lung Volume Reduction With Incomplete Lobar Fissures: An Experimental Pilot Animal Study. J Bronchol Interv Pulmonol. 2019 Aug;1. Reference #2: Global Initiative for Chronic Obstructive Lung Disease (GOLD): Global Strategy for the Diagnosis, Management, and Prevention of COPD 2020. Reference #3: Koster D, Slebos D-J. The fissure: interlobar collateral ventilation and implications for endoscopic therapy in emphysema. Int J Chron Obstruct Pulmon Dis. 2016 Apr;765. DISCLOSURES: No relevant relationships by Sidhu Gangadharan, source=Web Response No relevant relationships by Fayez Kheir, source=Web Response Consultant relationship with Boston Scientific Please note: $1001 - $5000 by Adnan Majid, source=Web Response, value=Consulting fee Consultant relationship with olympus Please note: $5001 - $20000 by Adnan Majid, source=Web Response, value=Consulting fee Consultant relationship with pinacle biologics Please note: $1001 - $5000 by Adnan Majid, source=Web Response, value=Consulting fee Consultant relationship with cook medical Please note: $1001 - $5000 by Adnan Majid, source=Web Response, value=Consulting fee No relevant relationships by Daniel Ospina-Delgado, source=Web Response

An Integrative Approach of the Fissure Completeness Score and Chartis Assessment in Endobronchial Valve Treatment for Emphysema.

PurposeLung volume reduction using one-way endobronchial valves is a bronchoscopic treatment for patients with severe emphysema without collateral ventilation between the treatment target lobe and the ipsilateral lobe(s). CT-scan fissure analysis is often used as a surrogate to predict the absence of collateral ventilation. We aimed to evaluate the predictive value of the fissure completeness score (FCS) compared to the functional Chartis measurement of collateral ventilation and to provide cut-off values of the FCS in patient selection.Patients and MethodsMulticenter study in patients eligible for treatment with one-way valves. The FCS was calculated by quantitative CT analysis (Thirona, the Netherlands) and compared to status of interlobar collateral ventilation measured with Chartis system (PulmonX, USA). Thresholds were calculated for the predictive values of the presence of collateral ventilation.ResultsAn FCS >95% of the left major fissure had a positive predictive value (PPV) of 91%, with 1 in 11 fissures demonstrating collateral ventilation with Chartis measurement, whereas an FCS of ≤80% had a negative predictive value (NPV) of 100% for the presence of collateral ventilation. For the right major fissure, the NPV was 100% for an FCS ≤90%, but 69.7% for the right upper lobe fissure.ConclusionQuantitative CT analysis is recommended in all patients evaluated for endobronchial valves. Patients with incomplete fissures (left major fissure: FCS <80%; right major fissure: <90%) can be excluded from Chartis measurement and endobronchial valve treatment. In patients with more complete fissures, the FCS is not specific enough for endobronchial valve treatment decisions. In this case, additional Chartis measurements are always recommended in the right lung. For the left lung, Chartis assessments may be omitted if the FCS is >95%.

Bronchoscopic interventions for emphysema: Current status.

Chronic obstructive pulmonary disease is a prevalent and progressive disease. The recently developed bronchoscopic lung volume reduction (BLVR) techniques offer personalized therapeutic options in subgroups of patients with severe emphysema. Endobronchial and intrabronchial valves (EBV/IBV) achieve lung volume reduction by lobar atelectasis. The lung volume reduction coils (LVRCs) and bronchoscopic thermal vapor ablation (BTVA) induce tissue compression, either mechanically or through inflammatory processes. While the effects of EBV/IBV are reversible by removing the implants, the effects of LVRC are partially reversible and that of BTVA is irreversible. The presence of interlobar collateral ventilation (CV) impacts on EBV/IBV treatment outcome due to its mechanism of action. Therefore, using radiological and endoscopic techniques to assess CV has a vital importance. Current evidence of BLVR demonstrates acceptable safety and short-term clinical efficacy. However, head-to-head trials are lacking, and further research is needed to establish long-term clinical benefit, durability, and cost-effectiveness of these techniques.

Interventional Bronchoscopy in the Management of Chronic Obstructive Lung Disease

Background: Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation, hyperinflation and reduced gas exchange that lead to progressive dyspnea. Pulmonary rehabilitation, lifestyle changes, pharmacotherapy, long-term oxygen therapy, noninvasive ventilation and surgical therapeutic approaches are the basic management strategies. Purpose: In the last 15 years, various bronchoscopic therapeutic modalities have emerged for severe COPD. The aim of this review is to summarize the effects of these bronchoscopic treatments compared with lung rehabilitation and pharmacological therapies. Methods: A PubMed search for the eligible studies and reviews on interventional bronchoscopy and COPD has been conducted. Results: Bronchoscopic lung volume reduction (LVR) techniques are targeted to reduce hyperinflation. The efficacy of reversible valve implantation has been confirmed in several randomized controlled trials. It provides clinical benefit in the absence of interlobar collateral ventilation. Nonblocking bronchoscopic LVR with coils, thermal vapor or sealants is independent of collateral ventilation but has not been studied sufficiently. Partially irreversible coil implantation leads to parenchymal compression while irreversible LVR with thermal vapor or sealants induce an inflammatory reaction. Targeted lung denervation ablates parasympathetic pulmonary nerves in COPD for sustainable bronchodilation, and liquid nitrogen metered cryospray destroys hyperplastic goblet cells and excessive submucous glands in the central airways to induce mucosal regeneration in chronic bronchitis. Conclusion: The best-examined bronchoscopic LVR method is the valve therapy. The data from the other modalities are still limited. Further studies are required to select the patients that will optimally benefit from a particular treatment and to predict and treat the procedure-related complications.

ENDOBRONCHIAL VALVE TREATMENT OF SEVERE EMPHYSEMA IN PATIENTS WITH ALPHA-1 ANTITRYPSIN DEFICIENCY

ENDOBRONCHIAL VALVE TREATMENT OF SEVERE EMPHYSEMA IN PATIENTS WITH ALPHA-1 ANTITRYPSIN DEFICIENCY

Collateral Ventilation Measurement Using Chartis: Procedural Sedation vs General Anesthesia

Absence of interlobar collateral ventilation is key to successful endobronchial valve treatment in patients with severe emphysema and can be functionally assessed by using the Chartis measurement. This system has been validated during spontaneous breathing, undergoing procedural sedation (PS), but can also be performed under general anesthesia. Performing the Chartis measurement under PS is often challenging because of coughing, mucus secretion, and difficulties in maintaining an adequate level of sedation. The objective of this study was to investigate whether there is a difference in Chartis measurement outcomes between PS and general anesthesia. In this prospective study, patients underwent Chartis measurements under both PS and general anesthesia. Study outcomes were Chartis measurement duration, number of measurements, feasibility, and success rate. The study included 30 patients with severe emphysema (mean age, 62 years; median FEV1, 29%of predicted). Chartis measurement duration was significantly longer under PS than under general anesthesia (mean, 20.3 ± 4.2min vs15.1 ± 4.4 min; P< .001). There was no difference in the number (median [range]) of measurements performed (2 [1-3] for PS vs1 [1-3] for general anesthesia; P= 1.00). Chartis measurement was more feasible during general anesthesia (median sum of all feasibility scores, 12 [range, 6-26] for PS vs7 [5-13] for general anesthesia; P< .001). There was no statistical difference in success rate: 77%of PS cases vs97%of general anesthesia cases (P= .07). This study found that Chartis measurement under general anesthesia is faster and more feasible to perform compared with performance with PS, without affecting measurement outcomes. Clinicaltrials.gov; No. NCT03205826; URL: www.clinicaltrials.gov.

Bronchoscopic lung volume reduction using an endobronchial valve to treat a huge emphysematous bullae: a case report

BackgroundIn patients with chronic obstructive pulmonary disease (COPD), bronchoscopic lung volume reduction (BLVR) techniques using unidirectional endobronchial valves improve lung function and increase exercise tolerance. BLVR treatment is included in the Global Initiative for Chronic Obstructive Lung Disease (GOLD) treatment guidelines for COPD patients without interlobar collateral ventilation. However, BLVR using an endobronchial valve has not been attempted in patients with giant bullae.Case presentationWe report successful and safe BLVR using an endobronchial valve in a patient with a huge bullous emphysema in the right middle lobe. A 65-year-old male was diagnosed with COPD 5 years prior and had a large bullae in the right middle lobe at that time. During regular follow-up, the symptoms of respiratory distress gradually worsened, and the size of the bullae gradually increased on computed tomography (CT). Therefore, we decided to treat the patient via BLVR using an unidirectional endobronchial valve. The Chartis system (Pulmonx, Inc., Palo Alto, CA) confirmed the absence of collateral ventilation of the right middle lobe. We successfully inserted an endobronchial valve into the right middle bronchus. After insertion, the bullae decreased dramatically in size, and the patient’s symptoms and quality of life improved markedly.ConclusionThis case supports recent suggestions that BLVR can serve as a good alternative treatment for appropriately selected patients.

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

Background and objective:Endoscopic valve therapy is a treatment modality in patients with advanced emphysema and absent interlobar collateral ventilation (CV). So far, long-term outcome following valve implantation has been insufficiently evaluated. The aim of this study was to investigate the real-world efficacy of this interventional therapy over 3 years.Methods:From 2006 to 2013, 256 patients with severe emphysema in whom absent CV was confirmed underwent valve therapy. The 3-year effectiveness was evaluated by pulmonary function testing (VC, FEV1, RV, TLC), 6-minute-walk test (6-MWT) and dyspnea questionnaire (mMRC). Long-term outcome was also assessed according to the radiological outcome following valve placement.Results:Of 256 patients treated with valves, 220, 200, 187, 100 and 66 patients completed the 3-month, 6-month, 1-year, 2-year and 3-year follow-up (FU) visit, respectively. All lung function parameters, 6-MWT and mMRC were significantly improved at 3- and 6-month FU. At 1-year FU, patients still experienced a significant improvement of all outcome parameters expect VC (L) and TLC (%). At 2 years, RV (L and %) and TLC (L and %) remained significantly improved compared to baseline. Three years after valve therapy, sustained significant improvement in mMRC was observed and the proportion of patients achieving a minimal clinically important difference from baseline in RV and 6-MWT was still 71% and 46%, respectively. Overall, patients with complete lobar atelectasis exhibited superior treatment outcome with 3-year responder rates to FEV1, RV and 6-MWT of 10%, 79% and 53%, respectively.Conclusions:Patients treated by valves experienced clinical improvement over 1 year following valve therapy. Afterwards, clinical benefit gradually declines more likely due to COPD progression.

Chartis Measurement of Collateral Ventilation: Conscious Sedation versus General Anesthesia – A Retrospective Comparison

Background: Absence of interlobar collateral ventilation using the Chartis measurement is the key predictor for successful endobronchial valve treatment in severe emphysema. Chartis was originally validated in spontaneous breathing patients under conscious sedation (CS); however, this can be challenging due to cough, mucus secretion, mucosal swelling, and bronchoconstriction. Performing Chartis under general anesthesia (GA) avoids these problems and may result in an easier procedure with a higher success rate. However, using Chartis under GA with positive pressure ventilation has not been validated. Objectives: In this study we investigated the impact of anesthesia technique, CS versus GA, on the feasibility and outcomes of Chartis measurement. Methods: We retrospectively analyzed all Chartis measurements performed at our hospital from October 2010 until December 2017. Results: We analyzed 250 emphysema patients (median forced expiratory volume in 1 s 26%, range 12–52% predicted). In 121 patients (48%) the measurement was performed using CS, in 124 (50%) using GA, and in 5 (2%) both anesthesia techniques were used. In total, 746 Chartis readings were analyzed (432 CS, 277 GA, and 37 combination). Testing under CS took significantly longer than GA (median 19 min [range 5—65] vs. 11 min [3–35], p < 0.001) and required more measurements (3 [1–13] vs. 2 [1–6], p < 0.001). There was no significant difference in target lobe volume reduction after treatment (–1,123 mL [–3,604 to 332] in CS vs. –1,251 mL [–3,333 to –1] in GA, p = 0.35). Conclusions: In conclusion, Chartis measurement under CS took significantly longer and required more measurements than under GA, without a difference in treatment outcome. We recommend a prospective trial comparing both techniques within the same patients to validate this approach.

Cost-effectiveness of endobronchial valve treatment in patients with severe emphysema compared to standard medical care.

Bronchoscopic lung volume reduction using endobronchial valves (EBV) is an effective new treatment option for severe emphysema patients without interlobar collateral ventilation. The objective of this study was to perform an economic evaluation including the costs and cost-effectiveness of EBV treatment compared with standard medical care (SoC) from the hospital perspective in the short term and long term. For the short-term evaluation, incremental cost-effectiveness ratios (ICER) were calculated based on the 6-month end point data from the STELVIO randomized trial. For the long-term evaluation, a Markov simulation model was constructed based on STELVIO and literature. The clinical outcome data were quality-adjusted life-years (QALY) based on the EuroQol5-Dimensions (EQ5D) questionnaire, the 6-min walking distance (6MWD) and the St George's Respiratory Questionnaire (SGRQ). The mean difference between the EBV group and controls was €16 721/patient. In the short-term (6 months), costs per additional QALY was €205 129, the ICER for 6MWD was €160 and for SGRQ was €1241. In the long term, the resulting cost-effectiveness ratios indicate additional costs of €39 000 per QALY gained with a 5-year time horizon and €21 500 per QALY gained at 10 years. In comparison, historical costs per additional QALY 1 year after the coil treatment are €738 400, 5 years after lung volume reduction surgery are €48 415 and 15 years after double-lung transplantation are €29 410. The positive clinical effects of EBV treatment are associated with increased costs compared with SoC. Our results suggest that the EBV treatment has a favourable cost-effectiveness profile, also when compared with other treatment modalities for this patient group.

Interventional pulmonology in chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) and emphysema are widespread diseases associated with progressive dyspnea because of airflow limitation and hyperinflation. Fundamental therapeutic strategies consist of pulmonary rehabilitation, pharmacotherapy, long-term oxygen therapy, noninvasive ventilation, and surgical therapeutic approaches. In the last 14 years, endoscopic therapeutic modalities emerged as a substantial part of severe COPD and emphysema treatment. Techniques of the endoscopic lung volume reduction (ELVR) aim at reduction of hyperinflation. Thereby, the reversible valve implantation of which the efficacy was confirmed in various randomized controlled trials (RCT) results in lobar volume reduction and clinical benefit in emphysema patients with absent interlobar collateral ventilation. Nonblocking ELVR methods that are independent of collateral ventilation include the partially irreversible coil implantation leading to parenchymal compression, the irreversible bronchoscopic thermal vapor ablation and polymeric lung volume reduction both inducing inflammatory reaction. The nonblocking methods have been examined in only a few RCTs. The targeted lung denervation as a novel bronchoscopic therapy for COPD patients aims at sustainable bronchodilation by ablation of parasympathetic pulmonary nerves. The review summarizes the various endoscopic treatment approaches for managment of COPD and emphysema, their mechanism of action, their complications and the current available results of the most important RCTs.

One-Year Follow-Up after Endobronchial Valve Treatment in Patients with Emphysema without Collateral Ventilation Treated in the STELVIO Trial

Background: One-way endobronchial valve (EBV) treatment has shown safety and efficacy at 6 months after treatment in patients with severe emphysema and confirmed absence of interlobar collateral ventilation. Longer follow-up in this subgroup is not available. Objectives: To investigate the efficacy and safety of EBV treatment of the STELVIO cohort at a 1-year follow-up. Methods: Emphysema patients who have been treated with EBV in the STELVIO trial were invited for a voluntary 1-year follow-up visit. Both the original treatment group and the control group who crossed over to treatment have been included. Analyses are performed on the patients who attended the 1-year follow-up visit. Results: Sixty-four patients received EBV treatment. At 1 year, 40 patients (26 female; mean age 59 ± 8 years; FEV₁ 0.86 ± 0.29 L; RV 4.56 ± 1.00 L; 6MWD 367 ± 78 m; and SGRQ 56 ± 13 points) visited the hospital. Significant improvements (p < 0.001) were found for FEV₁ (+17%, 95% CI, 11 to 24), RV (-687 mL, 95% CI, -918 to -456), 6MWD (+61 m, 95% CI, 42 to 80), and SGRQ (-11 points, 95% CI, −17 to −6). Two patients died: 1 after 58 days due to progressive respiratory failure and 1 after 338 days of follow-up due to a myocardial infarction. Seventeen percent of the patients underwent valve replacement and 22% of the initially treated patients had permanent valve removal. In 22% of the patients, pneumothoraces occurred before 6 months, and none occurred between 6 and 12 months. Conclusions: EBV treatment results in clinically relevant benefits at 1 year of follow-up. Maintenance bronchoscopies to achieve this are needed. This study supports the use of EBV treatment in carefully selected patients with severe emphysema without collateral ventilation.

Endobronchial Valve Placement: Too Much Risk for the Benefit?

Synopsis: the STELVIO trial randomized patients without collateral interlobar ventilation to receive endobronchial valves or standard care as a treatment for severe COPD. Although improvement in the lung function and the exercise capacity was observed in the valve group, a significant rate of pneumothorax was also observed. Source: Klooster K, Ten HAcken NHT, Hartman JE et al. Endobronchial valves for emphysema without interlobar collateral ventilation. NEJM. 2015; 373: 2325–35.

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.

Another STEP forward in emphysema treatment

Patients with severe chronic obstructive pulmonary disease (COPD) suffer on a daily basis, despite important efforts to support this large patient population with pharmacotherapy. To potentially relieve symptoms, innovative bronchoscopic treatments have been developed in the past decade: the one-way endobronchial valve therapy for patients with severe emphysema and absence of interlobar collateral ventilation;1 the trans-bronchial airway bypass for severe emphysema, relying on the presence of collateral ventilation;2 nitinol coil treatment for a wide range of emphysema phenotypes independent of collateral ventilation;3 parasympathetic lung denervation for patients with COPD who respond well to anticholinergic agents;4 and sclerosing therapies such as crosslink compounds5 and steam,6 both of which target the most diseased parenchymal defects.

Outcomes of Endobronchial Valve Treatment Based on the Precise Criteria of an Endobronchial Catheter for Detection of Collateral Ventilation under Spontaneous Breathing

Background: Endoscopic lung volume reduction with valves is a valid therapeutic option for COPD patients with severe emphysema. The exclusion of interlobar collateral ventilation (CV) is an important predictor of clinical success. Objectives: Recently, a catheter-based endobronchial in vivo measurement system (Chartis, Pulmonx, USA) has become routine in the clinical evaluation of CV status in target lobes, but the criteria for phenotyping CV by Chartis evaluation have not yet been defined. We asked the questions, how many phenotypes can be identified using Chartis, what are the exact criteria to distinguish them, and how do the Chartis phenotypes respond to valve insertionκ Methods: In a retrospective study, 406 Chartis assessments of 166 patients with severe COPD were analyzed. Four Chartis phenotypes, CV positive (CV+), CV negative (CV-), low flow (LF) and low plateau were identified. Fifty-two patients without CV were treated with valves and followed for 3 months. Results: The Chartis phenotypes were discriminated with respect to decline in expiratory peak flow, increase in resistance index and change in total exhaled volume after 1, 2, 3, 4 and 5 min of measurement time (p < 0.0001, ANOVA), and the cutoff criteria were defined accordingly. To examine the application of these phenotyping criteria, students applied them to 100 Chartis assessments, and they demonstrated almost perfect inter- and intraobserver agreements (κ > 0.9). Compared to baseline, CV- and LF patients with ipsilateral CV- lobe showed an improvement in FEV₁ (p < 0.05), vital capacity (p < 0.05) and target lobe volume reduction (p < 0.005) after valve insertion. Conclusion: This study describes the most prevalent Chartis phenotypes.

Endobronchial Valves for Emphysema without Interlobar Collateral Ventilation

BackgroundBronchoscopic lung-volume reduction with the use of one-way endobronchial valves is a potential treatment for patients with severe emphysema. To date, the benefits have been modest but have been hypothesized to be much larger in patients without interlobar collateral ventilation than in those with collateral ventilation.MethodsWe randomly assigned patients with severe emphysema and a confirmed absence of collateral ventilation to bronchoscopic endobronchial-valve treatment (EBV group) or to continued standard medical care (control group). Primary outcomes were changes from baseline to 6 months in forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and 6-minute walk distance.ResultsEighty-four patients were recruited, of whom 16 were excluded because they had collateral ventilation (13 patients) or because lobar segments were inaccessible to the endobronchial valves (3 patients). The remaining 68 patients (mean [±SD] age, 59±9 years; 46 were women) were randomly assigned to the EBV group (34 patients) or the control group (34). At baseline, the FEV1 and FVC were 29±7% and 77±18% of the predicted values, respectively, and the 6-minute walk distance was 374±86 m. Intention-to-treat analyses showed significantly greater improvements in the EBV group than in the control group from baseline to 6 months: the increase in FEV1 was greater in the EBV group than in the control group by 140 ml (95% confidence interval [CI], 55 to 225), the increase in FVC was greater by 347 ml (95% CI, 107 to 588), and the increase in the 6-minute walk distance was greater by 74 m (95% CI, 47 to 100) (P<0.01 for all comparisons). By 6 months, 23 serious adverse events had been reported in the EBV group, as compared with 5 in the control group (P<0.001). One patient in the EBV group died. Serious treatment-related adverse events in this group included pneumothorax (18% of patients) and events requiring valve replacement (12%) or removal (15%).ConclusionsEndobronchial-valve treatment significantly improved pulmonary function and exercise capacity in patients with severe emphysema characterized by an absence of interlobar collateral ventilation. (Funded by the Netherlands Organization for Health Research and Development and the University Medical Center Groningen; Netherlands Trial Register number, NTR2876.)