Lung transplant airway complications treated with biodegradable airway stents: The Dutch multi-center experience.

INTRODUCTION: Treatment of post lung-transplant airway complications is challenging, and treatment with conventional airway stents is associated with adverse events. More recently, biodegradable airway stents (BDS) have been introduced and may be used to reduce these adverse events. In this study we explore the feasibility of treatment with BDS post lung transplant. METHODS: All patients treated with BDS in The Netherlands were included in this retrospective multicenter study. Feasibility, life span of the stent, occurrence of adverse events, and evolution of lung function were evaluated. RESULTS: Twelve patients (six malacia and six stenosis) received a total of 57 BDS, ranging from 1 to 10 BDS per patient. Six patients had been pretreated with conventional airway stents. Median stent life span was 112 days (range 66-202). No adverse events occurred during stent placement. In 5 out of 57 stent placements, a single additional bronchoscopy was necessary because of mucus accumulation (n = 4) or excessive granulation tissue (n = 1). All stent naïve patients became airway stent independent after treatment; all patients pretreated with conventional airway stents were still airway stent dependent at the end of follow up. CONCLUSION: Treatment with BDS is safe and feasible. Adverse events were mild and easily treatable. All patients with initial treatment with BDS were airway stent independent at the end of follow up with a median treatment of 4 BDS.

Prevalence and Impact of COVID-19 among Severe COPD Patients post Bronchoscopic Lung Volume Reduction Treatment with Endobronchial Valves.

BACKGROUND: The COVID-19 pandemic has a great impact on numberless aspects of our society. In our bronchoscopic lung volume reduction interventional program, we work with severe COPD patients on a daily basis. OBJECTIVES: We were interested in the prevalence and outcome of COVID-19, impact of the pandemic on daily life, and the vaccination coverage in our severe COPD patients who have been treated with one-way endobronchial valves. METHOD: A questionnaire, which consisted of questions related to the infection rate, treatment, and outcome of COVID-19 infections; feelings of anxiety related to the pandemic; adherence to preventive measures; and willingness to be vaccinated; was sent to our patients in June 2021. RESULTS: The questionnaire was sent to 215 patients, and the response rate was 100%. The vaccination rate was 97% in our surveyed population. The majority of patients (63%) indicated that they were quite or very anxious to get infected with COVID-19. Twenty-five (11.5%) patients were diagnosed with COVID-19, with none of these patients having been vaccinated at the time of infection. The infection rate reported in this study is comparable to that of the general Dutch population. However, the hospital admission rate and mortality rates are higher. CONCLUSIONS: Our results show that the SARS-CoV-2 infection rate in severe COPD patients treated with endobronchial valves was comparable with the general population; however, the hospital admission and mortality rates were worse.

Effect of Chest Computed Tomography Kernel Use on Emphysema Score in Severe Chronic Obstructive Pulmonary Disease Patients Evaluated for Lung Volume Reduction.

BACKGROUND: Chest computed tomography (CT) emphysema quantification is a vital diagnostic tool in patient evaluation for bronchoscopic lung volume reduction (BLVR). Smooth kernels for CT image reconstruction are generally recommended for quantitative analyses. This recommendation is not always followed, which may affect quantification of emphysema extent and eventually, treatment decisions. OBJECTIVE: The main goal is to demonstrate the influence of CT reconstruction kernels on emphysema quantification in patients with severe COPD, considered for BLVR. METHODS: Chest CT scans were acquired with one multi-detector CT system and reconstructed using three different kernels: smooth, medium smooth, and sharp. Other parameters were kept constant. Emphysema scores (ESs), meaning the percentage of voxels below -950 Hounsfield units, were calculated and compared to the smooth reference kernel using paired t tests. Bland-Altman plots were made to assess the biases and limits of agreement between kernels. RESULTS: Ninety-eight COPD patient CT scans were analyzed. The sharp kernel had a systematic bias of 6.2% and limits of agreement of 16.6% to -4.2% compared to the smooth kernel. The medium smooth kernel had a systematic bias of 5.7% and limits of agreement of 9.2% and 2.2% compared to the smooth kernel. The ES differed, for a single patient, up to 18% for different kernels. CONCLUSIONS: Chest CT kernel reconstruction can lead to a significant difference in emphysema severity quantification. This may cause invalid treatment selection in COPD patients evaluated for BLVR. Standardization of a smooth CT kernel setting and/or normalization to a standard kernel is strongly recommended.

Bronchoscopic Lung Volume Reduction in Patients with Emphysema due to Alpha-1 Antitrypsin Deficiency.

BACKGROUND: Bronchoscopic lung volume reduction using one-way endobronchial valves (EBVs) is a valid therapy for severe emphysema patients. However, alpha-1 antitrypsin (AAT)-deficient patients were excluded from the majority of clinical trials investigating this intervention. OBJECTIVES: The aim of this study was to investigate the feasibility, efficacy, and safety of EBV treatment in patients with AAT deficiency (AATD) or a reduced AAT level. METHOD: A retrospective analysis was performed of all patients treated with EBV with confirmed AATD or with a reduced AAT serum level at the University Medical Center Groningen between 2013 and 2021. Baseline and 6-month follow-up assessment included chest CT, pulmonary function measurement, 6-min walking distance (6MWD), and St. George's Respiratory Questionnaire (SGRQ). RESULTS: In total, 53 patients were included, 30 patients in the AATD group (AAT <0.6 g/L or confirmed ZZ phenotype) and 23 patients in the reduced AAT group (AAT 0.6-1 g/L). In both groups, all response variables improved significantly after treatment. There was a median increase in forced expiratory volume in 1 s of 105 mL (12% relative) and 280 mL (31% relative) in the AATD and reduced AAT groups, respectively. 6MWD increased by 62 min and 52 min, and SGRQ decreased by 12.5 patients and 18.7 patients, respectively. A pneumothorax occurred in 10% and 13% of patients, and no patients died. CONCLUSIONS: EBV treatment in patients with emphysema and AATD or a reduced AAT level is feasible and results in significant improvements in pulmonary function, exercise capacity, and quality of life and has an acceptable safety profile.

Endobronchial Valve Treatment Does Not Cause Significant Nickel Deposition in Lung Tissue.

Bronchoscopic lung volume reduction using endobronchial valves (EBVs) is a treatment option for patients with severe emphysema. These EBVs are made out of a nitinol mesh covered by a silicone layer. Nitinol is an alloy of nickel and titanium and is commonly used in implantable medical devices because of its biocompatibility and memory-shape properties. However, there are some concerns that nickel ions can be released from nitinol-containing devices which might cause adverse health effects, especially in patients with a known nickel hypersensitivity. In vitro, it was found that EBV release significant amounts of nickel in the first hours. Our aim was to assess the nickel concentration in lung tissue from a patient who previously underwent EBV treatment but, due to treatment failure, underwent lung volume reduction surgery and to compare this to a reference sample. We found no significant difference in the median nickel concentration between the EBV-treated patient and the non-EBV-treated patient (0.270 vs. 0.328 µg/g, respectively, p = 0.693) and these concentrations were also comparable to previously published nickel concentrations in human lung tissue samples not having any medically implanted devices in the lung. Our results suggest that there is no significant long-term nickel deposition in lung tissue after EBV treatment.

Impact of Endobronchial Valve Treatment on Lung Function Decline.

INTRODUCTION: Endobronchial valve (EBV) treatment has been shown to be beneficial for patients with severe emphysema. The forced expiratory volume in 1 s (FEV1) was found to be significantly higher compared to baseline for up to 3 years after treatment although the magnitude of improvement gradually decreases over time. So far, it has not been investigated whether this treatment decelerates the decline in lung function. Therefore, our aim was to investigate the lung function decline before and after EBV treatment. METHODS: We included patients who were treated with EBVs in our hospital, of whom pre-treatment spirometry results were available (at least 4 measurements within at least 2 years before treatment) and who had an annual FEV1 measurement up to 3 years after treatment. RESULTS: In total, 45 patients were included (73% female, FEV1: 28 ± 7% of predicted, residual volume: 232 ± 32% of predicted) who had a mean pre-treatment FEV1 decline of -64 mL/year. Mean FEV1 "decline" after treatment was +13 mL/year, since FEV1 was still above the baseline level at 3-year follow-up. However, the FEV1 decline between 1 and 3 years of follow-up was not significantly different compared to the pre-treatment decline (-73 mL/year, p = 0.179). CONCLUSIONS: Our results show that the EBV treatment does not influence the progression of disease in terms of lung function decline. However, the treatment does improve the FEV1 up to a level that is still comparable 3 years after treatment with the baseline level.

Bronchoscopic Lung Volume Reduction Coil Treatment for Severe Emphysema: A Systematic Review and Meta-Analysis of Individual Participant Data.

BACKGROUND: Lung volume reduction coil (LVR-coil) treatment provides a minimally invasive treatment option for severe emphysema patients which has been studied in multiple clinical trials. OBJECTIVES: The aim of the study was to assess the effect of LVR-coil treatment on pulmonary function, quality of life, and exercise capacity using individual participant data. METHOD: PubMed, Web of Science, and EMBASE were searched until May 17, 2021. Prospective single-arm and randomized controlled trials that evaluated the effect of LVR-coil treatment on forced expiratory volume in 1 s (FEV1), residual volume (RV), St. George Respiratory Questionnaire (SGRQ) total score, and/or 6-min walk distance (6MWD) and were registered in an official clinical trial database were eligible for inclusion. Individual patient data were requested, and a linear mixed effects model was used to calculate overall treatment effects. RESULTS: Eight trials were included in the final analysis, representing 680 individual patients. LVR-coil treatment resulted in a significant improvement in FEV1 at 3- (0.09 L [95% confidence interval (95% CI): 0.06-0.12]) and 6-month follow-up (0.07 L [95% CI: 0.03-0.10]), a significant reduction in RV at 3- (-0.45L [95% CI: -0.62 to -0.28]), 6- (-0.33L [95% CI: -0.52 to -0.14]), and 12-month follow-up (-0.36L [95% CI: -0.64 to -0.08]), a significant reduction in SGRQ total score at 3- (-12.3 points [95% CI: -15.8 to -8.8]), 6- (-10.1 points [95% CI: -12.8 to -7.3]), and 12-month follow-up (-9.8 points [95% CI: -15.0 to -4.7]) and a significant increase in 6MWD at 3-month follow-up (38 m [95% CI: 18-58]). CONCLUSIONS: LVR-coil treatment in emphysema patients results in sustained improvements in pulmonary function and quality of life and shorter lived improvements in exercise capacity. Since the owner of this LVR-coil has decided to stop the production and newer generations LVR-coils are currently being developed, these results can act as a reference for future studies and clinical guidance.

Effect of Bronchoscopic Lung Volume Reduction in Advanced Emphysema on Energy Balance Regulation.

BACKGROUND: Hypermetabolism and muscle wasting frequently occur in patients with severe emphysema. Improving respiratory mechanics by bronchoscopic lung volume reduction (BLVR) might contribute to muscle maintenance by decreasing energy requirements and alleviating eating-related dyspnoea. OBJECTIVE: The goal was to assess the impact of BLVR on energy balance regulation. DESIGN: Twenty emphysematous subjects participated in a controlled clinical experiment before and 6 months after BLVR. Energy requirements were assessed: basal metabolic rate (BMR) by ventilated hood, total daily energy expenditure (TDEE) by doubly labelled water, whole body fat-free mass (FFM) by deuterium dilution, and physical activity by accelerometry. Oxygen saturation, breathing rate, and heart rate were monitored before, during, and after a standardized meal via pulse oximetry and dyspnoea was rated. RESULTS: Sixteen patients completed follow-up, and among those, 10 patients exceeded the minimal clinically important difference of residual volume (RV) reduction. RV was reduced with median (range) 1,285 mL (-2,430, -540). Before BLVR, 90% of patients was FFM-depleted despite a normal BMI (24.3 ± 4.3 kg/m2). BMR was elevated by 130%. TDEE/BMR was 1.4 ± 0.2 despite a very low median (range) daily step count of 2,188 (739, 7,110). Following BLVR, the components of energy metabolism did not change significantly after intervention compared to before intervention, but BLVR treatment decreased meal-related dyspnoea (4.1 vs. 1.7, p = 0.019). CONCLUSIONS: Impaired respiratory mechanics in hyperinflated emphysematous patients did not explain hypermetabolism. Clinical Trial Registry Number: NCT02500004 at www.clinicaltrial.gov.

Identifying Responders and Exploring Mechanisms of Action of the Endobronchial Coil Treatment for Emphysema.

BACKGROUND: So far, 3 randomized controlled trials have shown that the endobronchial treatment using coils is safe and effective. However, the more exact underlying mechanism of the treatment and best predictors of response are unknown. OBJECTIVES: The aim of the study was to gain more knowledge about the underlying physiological mechanism of the lung volume reduction coil treatment and to identify potential predictors of response to this treatment. METHODS: This was a prospective nonrandomized single-center study which included patients who were bilaterally treated with coils. Patients underwent an extensive number of physical tests at baseline and 3 months after treatment. RESULTS: Twenty-four patients (29% male, mean age 62 years, forced expiratory volume in 1 s [FEV1] 26% pred, residual volume (RV) 231% pred) were included. Three months after treatment, significant improvements were found in spirometry, static hyperinflation, air trapping, airway resistance, treated lobe RV and treated lobes air trapping measured on CT scan, exercise capacity, and quality of life. The change in RV and airway resistance was significantly associated with a change in FEV1, forced vital capacity, air trapping, maximal expiratory pressure, dynamic compliance, and dynamic hyperinflation. Predictors of treatment response at baseline were a higher RV, larger air trapping, higher emphysema score in the treated lobes, and a lower physical activity level. CONCLUSIONS: Our results confirm that emphysema patients benefit from endobronchial coil treatment. The primary mechanism of action is decreasing static hyperinflation with improvement of airway resistance which consequently changes dynamic lung mechanics. However, the right patient population needs to be selected for the treatment to be beneficial which should include patients with severe lung hyperinflation, severe air trapping, and significant emphysema in target lobes.

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

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

Endobronchial Coil System versus Standard-of-Care Medical Management in the Treatment of Subjects with Severe Emphysema.

BACKGROUND: Bronchoscopic lung volume reduction using endobronchial coils is a new treatment for patients with severe emphysema. To date, the benefits have been modest and have been suggested to be much larger in patients with severe hyperinflation and nonmulti-comorbidity. OBJECTIVE: We aimed to evaluate the efficacy and safety of endobronchial coil treatment in a randomized multicenter clinical trial using optimized patient selection. METHOD: Patients with severe emphysema on HRCT scan with severe hyperinflation (residual volume [RV] ≥200% predicted and RV/total lung capacity [TLC] >55%) were randomized to coil treatment or control. Primary outcome measures were differences in the forced expiratory volume in 1 s (FEV1) and St George's Respiratory Questionnaire (SGRQ) total score at 6 months. RESULTS: Due to premature study termination, a total of 120 patients (age 63 ± 7 years, FEV1 29 ± 7% predicted, RV 251 ± 41% predicted, RV/TLC 67 ± 6%, and SGRQ 58 ± 13 points), instead of 210 patients, were randomized. At study termination, 91 patients (57 coil and 34 control) had 6-month results available. Analyses showed significantly greater improvements in favor of the coil group. The increase in FEV1 was greater in the coil group than that in the control group by + 10.3 [+4.7 to +16.0] % and in SGRQ by -10.6 [-15.9 to -5.4] points. At study termination, there were 5 (6.8%) deaths in the coil cohort reported. CONCLUSION: Despite early study termination, coil treatment compared to control results in a significant improvement in the lung function and quality of life benefits for up to 6 months in patients with emphysema and severe hyperinflation. These improvements were of clinical importance but were associated with a higher likelihood of serious adverse events.

Comparison of Multiple Diagnostic Tests to Measure Dynamic Hyperinflation in Patients with Severe Emphysema Treated with Endobronchial Coils.

PURPOSE: For this study, we aimed to compare dynamic hyperinflation measured by cardiopulmonary exercise testing (CPET), a six-minute walking test (6-MWT), and a manually paced tachypnea test (MPT) in patients with severe emphysema who were treated with endobronchial coils. Additionally, we investigated whether dynamic hyperinflation changed after treatment with endobronchial coils. METHODS: Dynamic hyperinflation was measured with CPET, 6-MWT, and an MPT in 29 patients before and after coil treatment. RESULTS: There was no significant change in dynamic hyperinflation after treatment with coils. Comparison of CPET and MPT showed a strong association (rho 0.660, p < 0.001) and a moderate agreement (BA-plot, 202 ml difference in favor of MPT). There was only a moderate association of the 6-MWT with CPET (rho 0.361, p 0.024). CONCLUSION: MPT can be a suitable alternative to CPET to measure dynamic hyperinflation in severe emphysema but may overestimate dynamic hyperinflation possibly due to a higher breathing frequency.

A prospective safety and feasibility study of metered cryospray for patients with chronic bronchitis in COPD.

BACKGROUND: No currently approved intervention counteracts airway metaplasia and mucus hypersecretion of chronic bronchitis in COPD. However, metered cryospray (MCS) delivering liquid nitrogen to the tracheobronchial airways ablates abnormal epithelium and facilitates healthy mucosal regeneration. The objective of this study was to evaluate the feasibility, efficacy and safety of MCS in chronic bronchitis. METHODS: Patients with a forced expiratory volume in 1 s of 30-80% predicted who were taking optimal medication were recruited. Primary outcomes were feasibility (completion of treatments), efficacy (3-month change in St George's Respiratory Questionnaire (SGRQ)) and safety (incidence of adverse events). Secondary outcomes were lung function, exercise capacity and additional patient-reported outcomes. RESULTS: 35 patients, 19 male/16 female, aged 47-76 years, Global Initiative for Chronic Obstructive Lung Disease grade I (n=3), II (n=10) and III (n=22), underwent staggered liquid nitrogen treatments to the tracheobronchial tree. 34 patients completed three treatments, each lasting 34.3±12.1 min, separated by 4-6 weeks; one withdrew after the first treatment. ∼1800 doses of MCS were delivered. Clinically meaningful improvements in patient-reported outcomes were observed at 3 months: change in SGRQ -6.4 (95% CI -11.4 to -1.3; p=0.01), COPD Assessment Test (CAT) -3.8 (95% CI -6.4 to -1.3; p<0.01) and Leicester Cough Questionnaire (LCQ) 21.6 (95% CI 7.3 to 35.9; p<0.01). Changes in CAT were durable to 6 months (-3.4, 95% CI -5.9 to -0.9; p=0.01); changes in SGRQ and LCQ were durable to 9 months (-6.9, 95% CI -13.0 to -0.9; p=0.03 and 13.4, 95% CI 2.1 to 24.6; p=0.02, respectively. At 12 months, 14 serious adverse events were recorded in 11 (31.4%) subjects; six (43%) moderate and eight (57%) severe. Nine were respiratory-related: six exacerbations of COPD, two pneumonias and one case of increased coughing; all recovered without sequelae. None were serious device- or procedure-related adverse events. CONCLUSION: MCS is safe, feasible and associated with clinically meaningful improvements in multidimensional patient-reported outcomes.

First in Human Experience of the Performance of the New 5.5-LP Size Zephyr Endobronchial Valve.

BACKGROUND: Bronchoscopic lung volume reduction using the Zephyr® endobronchial valve (EBV) is a guideline treatment for patients with advanced emphysema. To achieve volume reduction, it is crucial that there is absence of collateral ventilation and a complete occlusion of the target lobe. While 3 EBV sizes (4.0; 4.0-LP; and 5.5) are currently available to accommodate all airway sizes, local anatomical variations sometimes warrant a valve with a wide diameter but shorter length. To address this, a new "low profile" 5.5-LP EBV has been introduced. OBJECTIVE: In this study, we evaluated the feasibility, safety, and efficacy of this new 5.5-LP EBV. METHODS: This was a single-center, prospective, open-label study. Patients were included if eligible for valve treatment with a local anatomy suitable to place at least one 5.5-LP EBV. Feasibility of placement of the 5.5-LP EBV was reported. Safety, CT parameters, pulmonary function tests, and St. George's Respiratory Questionnaire (SGRQ) were assessed at baseline and 6 weeks after treatment. RESULTS: We included 30 patients with severe chronic obstructive pulmonary disease (forced expiratory volume in 1 s [FEV1] 29 ± 10%; [RV] 242 ± 46%; and SGRQ 56 ± 11 points). Besides the regular EBV sizes, a median of 1 (1-3) of the new 5.5-LP EBV was placed. No valve adjustment was needed during the initial procedure. A single asymptomatic small pneumothorax was observed in 1 patient. In 4 patients, a revision bronchoscopy was performed due to absence of clinical benefit. In 1 patient, this was related to a dislocation of the 5.5-LP EBV. Clinically relevant improvements were seen in target lobar volume reduction (-1,554 mL), FEV1 +39%, RV -960 mL, and SGRQ -18 points. CONCLUSIONS: In this first in human study, the 5.5-LP EBV could be placed into wide segments with a shorter landing length without unexpected complications and with good efficacy outcomes.

Endobronchial Valve Treatment in Emphysema Patients with a Very Low DLCO.

BACKGROUND: For selected patients with severe emphysema, bronchoscopic lung volume reduction with endobronchial valves (EBV) is recognized as an additional treatment option. In most trials investigating EBV treatment, patients with a very low diffusing capacity (DLCO) were excluded from participation. OBJECTIVES: Our goal was to investigate whether EBV treatment in patients with emphysema with a very low DLCO is safe and effective. METHODS: This was a single-center retrospective analysis including patients with emphysema and a DLCO ≤20%pred who underwent EBV treatment. Follow-up was performed 6 months post-treatment. Outcome parameters were compared to a historical matched control group (DLCO >20%pred, matched for sex, age, forced expiratory volume in 1 s [FEV1], and residual volume [RV]). RESULTS: Twenty patients (80% female, 64 ± 6 years, FEV1 26 ± 6%pred, RV 233 ± 45%pred, DLCO 18 ± 1.6%pred) underwent EBV treatment. At 6 months follow-up, we found a statistically significant improvement in FEV1 (0.08 ± 0.12 L), RV (-0.45 ± 0.95 L), 6-min walking distance (38 ± 65 m), and St. George's Respiratory Questionnaire (-12 ± 13 points). With the exception of FEV1, all exceeded the minimal clinically important difference. The most common serious adverse event was a pneumothorax requiring intervention (15%). There were no significant differences in outcome compared to the DLCO >20%pred control group. CONCLUSIONS: In this single-center retrospective analysis, we showed statistically significant and clinically relevant improvements in lung function, exercise capacity, and quality of life up to 6 months after EBV treatment in emphysema patients with a DLCO ≤20% (14-20%) of predicted with no increased risk of serious adverse events.

CT-Derived Pulmonary Artery Diameters to Preselect for Echocardiography in COPD Patients Eligible for Bronchoscopic Treatments.

BACKGROUND: Currently, patients with COPD who are evaluated for bronchoscopic treatments are routinely screened for pulmonary hypertension (PH) and systolic left ventricle dysfunction by echocardiography. OBJECTIVES: We evaluated the prevalence of PH and systolic left ventricle dysfunction in this patient group and investigated if the previously proposed CT-derived pulmonary artery to aorta (PA:A) ratio >1 and PA diameter measurements can be used as alternative screening tools for PH. METHODS: Two hundred fifty-five patients were included in this retrospective analysis (FEV1 25%pred, RV 237%pred). All patients received transthoracic echocardiography and chest CT scans on which diameters of the aorta and pulmonary artery were measured at the bifurcation and proximal to the bifurcation. RESULTS: Following echocardiography, 3 patients (1.2%) had PH and 1 (0.4%) had systolic left ventricle dysfunction. Using a PA:A ratio >1, only 10.3% of the patients with a right ventricular systolic pressure (RVSP) ≥35 mm Hg were detected and none of the patients with an RVSP >50 mm Hg were detected. Patients with an RVSP ≥35 mm Hg had significantly higher PA diameters (29.5 vs. 27.5 mm; p = 0.02) but no significantly different PA:A ratios. All patients with an RVSP >50 mm Hg had PA diameters >30 mm. CONCLUSIONS: The prevalence of PH and systolic left ventricle dysfunction is low in this preselected cohort of patients with severe COPD. In this population, a PA:A ratio >1 is not a useful cardiac screening tool for PH. A PA diameter >30 mm could substitute for routinely performed echocardiography in the screening for PH in this patient group.

Temporary Right Middle Lobe Occlusion with a Blocking Device to Enable Collateral Ventilation Measurement of the Right Major Fissure.

BACKGROUND: Absence of interlobar collateral ventilation is essential to achieve lobar volume reduction after endobronchial valve (EBV) treatment and can be assessed using the Chartis measurement. However, especially in lower lobe measurements, Chartis can be complicated by the "no-flow phenomenon", during which a sudden cessation of flow is observed, leading to an unreliable measurement. If this phenomenon occurs in the right lower lobe, when measuring collateral flow over the right major fissure, the entrance to the right middle lobe should be occluded, and the Chartis balloon should be placed in the right upper lobe. Both Watanabe spigots and balloon catheters can be used to achieve occlusion. OBJECTIVE: Our aim was to demonstrate that right middle lobe occlusion with a blocking device is helpful in obtaining a reliable Chartis outcome in case of the no-flow phenomenon in the right lower lobe. METHODS: We performed a retrospective analysis of patients scheduled for EBV treatment in an EBV registry between September 2016 and September 2019. RESULTS: We included 15 patients with severe emphysema (median age 63 years [range 47-73], 73% female, and FEV1 24% [range 19-36] of predicted), who required temporary middle lobe occlusion (12 Watanabe spigot, 3 balloon catheter). After occlusion, a reliable Chartis outcome was obtained in all patients. CONCLUSION: Temporary middle lobe occlusion using a blocking device is helpful in obtaining a reliable Chartis outcome in case of a right lower lobe no-flow phenomenon.

Change in Dynamic Hyperinflation After Bronchoscopic Lung Volume Reduction in Patients with Emphysema.

BACKGROUND AND PURPOSE: In patients with severe emphysema, dynamic hyperinflation is superimposed on top of already existing static hyperinflation. Static hyperinflation reduces significantly after bronchoscopic lung volume reduction (BLVR). In this study, we investigated the effect of BLVR compared to standard of care (SoC) on dynamic hyperinflation. METHODS: Dynamic hyperinflation was induced by a manually paced tachypnea test (MPT) and was defined by change in inspiratory capacity (IC) measured before and after MPT. Static and dynamic hyperinflation measurements were performed both at baseline and 6 months after BLVR with endobronchial valves or coils (treatment group) or SoC (control group). RESULTS: Eighteen patients underwent BLVR (78% female, 57 (43-67) years, FEV1 25(18-37) %predicted, residual volume 231 (182-376) %predicted). Thirteen patients received SoC (100% female, 59 (44-74) years, FEV1 25 (19-37) %predicted, residual volume 225 (152-279) %predicted. The 6 months median change in dynamic hyperinflation in the treatment group was: + 225 ml (range - 113 to + 803) (p < 0.01) vs 0 ml (- 1067 to + 500) in the control group (p = 0.422). An increase in dynamic hyperinflation was significantly associated with a decrease in residual volume (r = - 0.439, p < 0.01). CONCLUSION: Bronchoscopic lung volume reduction increases the ability for dynamic hyperinflation in patients with severe emphysema. We propose this is a consequence of improved static hyperinflation.

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

BACKGROUND: Bronchoscopic lung volume reduction techniques are minor invasive treatment modalities for severely hyperinflated emphysema patients. The severity of static lung hyperinflation determines eligibility and success rate for these treatments. However, it is not exactly known what parameter should be used to optimally reflect hyperinflation. Commonly used parameters are residual volume (RV) and the RV/Total lung capacity (TLC) ratio. Other parameters reflecting hyperinflation are Inspiratory Capacity/TLC and forced vital capacity. OBJECTIVES: To define which of these function parameters is the most optimal reflection of hyperinflationin in relation to patient-related outcomes. METHODS: In a retrospective cohort study, data from measurements during baseline visits of eight studies were pooled. Primary outcomes were RV/TLC ratio and RV as percentage of predicted (RV%pred), both measured by bodyplethysmography, compared to the patient-related outcome variables: 6-min walk distance (6MWD), the St. George's Respiratory Questionnaire (SGRQ), and the modified Medical Research Council (mMRC). RESULTS: Two hundred seventy-four COPD patients (mean age 59 years; 66% female), FEV1 0.74 ± 0.28 L, RV 4.94 ± 1.06 L, 6MWD of 339 ± 95 m, were included in the analysis. Significant correlations (all p < 0.01) were found between RV%pred and 6MWD (r = - 0.358), SGRQ (r = 0.184), and mMRC (r = 0.228). Also, there was a significant correlation between RV/TLC ratio and 6MWD (r = - 0.563), SGRQ (r = 0.289) and mMRC (r = 0.354). Linear regression analyses showed that RV/TLC ratio was a better predictor of patient outcomes than RV%pred. CONCLUSION: This study demonstrates that both RV/TLC ratio and RV%pred are relevant indicators of hyperinflation in patients with severe emphysema in relation to patient-related outcomes. RV/TLC ratio is more strongly related to the patient-related outcomes than RV%pred.

CT-derived muscle remodelling after bronchoscopic lung volume reduction in advanced emphysema.

Muscle wasting frequently occurs in severe emphysema. Improving respiratory mechanics by bronchoscopic lung volume reduction using endobronchial valves (EBV) might prevent further loss or even increase in muscle mass. CT-derived skeletal muscle mass gain was observed in 39/49 patients 6 months after EBV. Multiple linear regression showed that gain in muscle (ß=2.4; 95% CI 0.2 to 4.6; p=0.036) and intramuscular fat (ß=3.1; 95% CI 0.2 to 5.9; p=0.035) is associated with improved 6 min walk distance independent of the change in residual volume. Skeletal muscle remodelling associates with improved exercise capacity after EBV, independent of hyperinflation reduction. TRIAL REGISTRATION NUMBER: Clinical trial registered with the Dutch trial register www.trialregister.nl (NTR2876), Results.