Clinical Utility of Quantitative CT Analysis for Fissure Completeness in Bronchoscopic Lung Volume Reduction: Comparison between CT and Chartis™

A 6-year experience of Zephyr endobronchial valves for severe emphysema in an Australian single-centre cohort

BACKGROUND

Endobronchial valve (EBV) insertion for lung volume reduction is a management option for patients with severe emphysema. One-way valves cause lobar deflation and improve lung function, exercise capacity and quality of life.

AIMS

To retrospectively analyse and compare the outcomes of the first 57 patients treated with EBVs between 2015 and 2021 at the Royal Adelaide Hospital to international standards.

METHODS

Clinical outcomes of forced expiratory volume in 1 s (FEV1), residual volume (RV), treated lobe volume reduction (TLVR) and 6-min walk distance (6MWD) at 3, 6 and 12 months after valve insertion were reviewed against established minimally clinically important differences (MCIDs). Complications and subjective breathlessness measured by Borg scores were also reviewed.

RESULTS

Fifty-seven patients were included. At 12 months, 77.2% achieved TLVR. FEV1 improved by 170 mL (95% confidence interval (CI): 100-250, P < 0.001), 80 mL (95% CI: 10-150, P = 0.019) and 40 mL (95% CI: -60 to 130, P 0.66) at 3, 6 and 12 months respectively. RV improved by -610 mL (95% CI: -330 to -900, P < 0.0001) at 3 months, -640 mL (95% CI: -360 to -920, P < 0.0001) at 6 months and -360 mL (95% CI: -60 to -680, P = 0.017) at 12 months. 6MWD improved by 57.34 m (95% CI: 36.23-78.45, P < 0.0001) and 44.93 m (95% CI: 7.19-82.67, P = 0.02) at 3 and 6 months. Borg score improved by -0.53 (95% CI: 0.11 to -1.2, P = 0.11) and -0.49 (95% CI: 0.17 to -1.15, P = 0.16) at 3 and 6 months. Complication rates aligned with international standards with mucous/infection (26.3%) and pneumothorax (17.5%) as the most common. Subgroup analysis signalled improved outcomes in patients with heterogeneous emphysema.

CONCLUSION

Our study represents the first publicly funded Australian analysis of EBVs. The results align with international prospective trials demonstrating improved lung function and exercise capacity. Australians with severe emphysema and gas trapping should be referred to a multidisciplinary centre for consideration of EBVs.

Advances in COPD imaging using CT and MRI: linkage with lung physiology and clinical outcomes

Recent years have witnessed major advances in lung imaging in patients with COPD. These include significant refinements in images obtained by computed tomography (CT) scans together with the introduction of new techniques and software that aim for obtaining the best image whilst using the lowest possible radiation dose. Magnetic resonance imaging (MRI) has also emerged as a useful radiation-free tool in assessing structural and more importantly functional derangements in patients with well-established COPD and smokers without COPD, even before the existence of overt changes in resting physiological lung function tests. Together, CT and MRI now allow objective quantification and assessment of structural changes within the airways, lung parenchyma and pulmonary vessels. Furthermore, CT and MRI can now provide objective assessments of regional lung ventilation and perfusion, and multinuclear MRI provides further insight into gas exchange; this can help in structured decisions regarding treatment plans. These advances in chest imaging techniques have brought new insights into our understanding of disease pathophysiology and characterising different disease phenotypes. The present review discusses, in detail, the advances in lung imaging in patients with COPD and how structural and functional imaging are linked with common resting physiological tests and important clinical outcomes.

Endobronchial valves for emphysema and persistent air-leak: 10-year experience in an Asian country

BACKGROUND

Endobronchial valve (EBV) therapy, a validated method for bronchoscopic lung volume reduction (BLVR) in severe emphysema, has been explored for persistent air-leak (PAL) management. However, its effectiveness and safety in the Asian population require further real-world evaluation. In this study, we assessed the outcomes of treatment with EBV within this demographic.

METHODS

We conducted a retrospective analysis of medical records from 11 Korean centers. For the emphysema cohort, inclusion criteria were patients diagnosed with emphysema who underwent bronchoscopy intended for BLVR. We assessed these patients for clinical outcomes of chronic obstructive pulmonary disease. All patients with PAL who underwent treatment with EBV were included. We identified the underlying causes of PAL and evaluated clinical outcomes after the procedure.

RESULTS

The severe emphysema cohort comprised 192 patients with an average age of 70.3 years, and 95.8% of them were men. Ultimately, 137 underwent treatment with EBV. Three months after the procedure, the BLVR group demonstrated a significant improvement in forced expiratory volume in 1 s (+160 mL vs. +30 mL; P = 0.009). Radiographic evidence of lung volume reduction 6 months after BLVR was significantly associated with improved survival (adjusted hazard ratio 0.020; 95% confidence interval 0.038-0.650; P = 0.010). Although pneumothorax was more common in the BLVR group (18.9% vs. 3.8%; P = 0.018), death was higher in the no-BLVR group (38.5% vs. 54.5%, P = 0.001), whereas other adverse events were comparable between the groups. Within the subset of 18 patients with PAL, the predominant causes of air-leak included spontaneous secondary pneumothorax (44.0%), parapneumonic effusion/empyema (22.2%), and post-lung resection surgery (16.7%). Following the treatment, the majority (77.8%) successfully had their chest tubes removed. Post-procedural complications were minimal, with two incidences of hemoptysis and one of empyema, all of which were effectively managed.

CONCLUSIONS

Treatment with EBV provides substantial clinical benefits in the management of emphysema and PAL in the Asian population, suggesting a favorable outcome for this therapeutic approach.

Meta-analysis and Systematic Review of Bronchoscopic Lung Volume Reduction Through Endobronchial Valves in Severe Emphysema

BACKGROUND

Pharmacologic therapeutics for advanced emphysema have limited benefit. Bronchoscopic lung volume reduction with endobronchial valves (EBVs) have reported improvements in lung function, breathlessness, and quality of life through randomized clinical trials, with less morbidity as comparted to Surgical Lung volume Reduction. We here present a Meta-analysis and systematic review of bronchoscopic lung volume reduction in advanced chronic obstructive lung disease patients.

METHODS

PubMed (NLM), Embase (Elsevier), and Web of Science (Clarivate Analytics) search was conducted using a combination of keywords and subject headings. The search was confined to the last 15 years and was completed on October 23, 2020. Only placebo-controlled randomized control trials of emphysema patients with EBV were included. Quality assessment was done by 2 independent reviewers.

RESULTS

Nine studies were included for the meta-analysis with a total number of 1383 patients of whom 888 received EBV and 495 standard of care (SOC) medications. Our Metanalysis show statistically significant improvement in forced expiratory volume in first second, percentage forced expiratory volume in first second, St. George's respiratory questionnaire, and 6-minute walk distance in EBV group compared with SOC. Residual volume had statistically significant reduction after EBV placement compared with SOC. These differences continued to be present during short-term (<=6 mo) and long-term follow-up (>=6 mo). These improvements were even higher when the EBV patients'. Collateral ventilation was negative/fissure was intact (CV-/FI >90%). The rate of hemoptysis and pneumothorax was higher in the EBV group compared with SOC, however, did not lead to increased fatal outcomes.

CONCLUSION

In conclusion, EBV has favorable effects on patients' outcomes in patients who have heterogeneous emphysema particularly with no collateral ventilation.

Deep Learning Prediction of Survival in Patients with Chronic Obstructive Pulmonary Disease Using Chest Radiographs

Background Preexisting indexes for predicting the prognosis of chronic obstructive pulmonary disease (COPD) do not use radiologic information and are impractical because they involve complex history assessments or exercise tests. Purpose To develop and to validate a deep learning-based survival prediction model in patients with COPD (DLSP) using chest radiographs, in addition to other clinical factors. Materials and Methods In this retrospective study, data from patients with COPD who underwent postbronchodilator spirometry and chest radiography from 2011-2015 were collected and split into training (n = 3475), validation (n = 435), and internal test (n = 315) data sets. The algorithm for predicting survival from chest radiographs was trained (hereafter, DLSP_CXR), and then age, body mass index, and forced expiratory volume in 1 second (FEV₁) were integrated within the model (hereafter, DLSP_integ). For external test, three independent cohorts were collected (n = 394, 416, and 337). The discrimination performance of DLSP_CXR was evaluated by using time-dependent area under the receiver operating characteristic curves (TD AUCs) at 5-year survival. Goodness of fit was assessed by using the Hosmer-Lemeshow test. Using one external test data set, DLSP_integ was compared with four COPD-specific clinical indexes: BODE, ADO, COPD Assessment Test (CAT), and St George's Respiratory Questionnaire (SGRQ). Results DLSP_CXR had a higher performance at predicting 5-year survival than FEV₁ in two of the three external test cohorts (TD AUC: 0.73 vs 0.63 [P = .004]; 0.67 vs 0.60 [P = .01]; 0.76 vs 0.77 [P = .91]). DLSP_CXR demonstrated good calibration in all cohorts. The DLSP_integ model showed no differences in TD AUC compared with BODE (0.87 vs 0.80; P = .34), ADO (0.86 vs 0.89; P = .51), and SGRQ (0.86 vs 0.70; P = .09), and showed higher TD AUC than CAT (0.93 vs 0.55; P < .001). Conclusion A deep learning model using chest radiographs was capable of predicting survival in patients with chronic obstructive pulmonary disease. © RSNA, 2022 Online supplemental material is available for this article.

Overview of Interventional Pulmonology for Radiologists

Interventional pulmonology is a growing field specializing in minimally invasive procedures of the mediastinum, lungs, airways, and pleura. These procedures have both diagnostic and therapeutic indications and are performed for benign and malignant diseases. Endobronchial US has been combined with transbronchial needle aspiration to extend tissue sampling beyond the airways and into the lungs and mediastinum. Recent innovations extending the peripheral access of bronchoscopy include electromagnetic navigational bronchoscopy and thinner bronchoscopes. An important indication for therapeutic bronchoscopy is the relief of central airway obstruction, which may be severe and life threatening. Techniques for restoring patency of the central airways include mechanical debulking and multiple modalities for ablation, stent placement, and balloon bronchoplasty. Bronchoscopic lung volume reduction improves quality of life in certain patients with severe emphysema and is an important less invasive alternative to lung volume reduction surgery. Bronchial thermoplasty is likewise a nonpharmacologic treatment in patients with severe uncontrolled asthma. Many of these procedures have unique selection criteria that require precise evaluations at preprocedure imaging. Postprocedure imaging is also essential in determining outcome success and the presence of complications. Radiologists should be familiar with these procedures as well as the relevant imaging features in both planning and later surveillance. Evolving techniques that may become more widely available in the near future include robotic-assisted bronchoscopy, bronchoscopic transparenchymal nodule access, transbronchial cryobiopsy, ablation of early-stage cancers, and endobronchial intratumoral chemotherapy. An invited commentary by Wayne et al is available online. ^©RSNA, 2021.

The Potential Role and Regulatory Mechanisms of MUC5AC in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is associated with high morbidity and mortality globally. Studies show that airway mucus hypersecretion strongly compromises lung function, leading to frequent hospitalization and mortality, highlighting an urgent need for effective COPD treatments. MUC5AC is known to contribute to severe muco-obstructive lung diseases, worsening COPD pathogenesis. Various pathways are implicated in the aberrant MUC5AC production and secretion MUC5AC. These include signaling pathways associated with mucus-secreting cell differentiation [nuclear factor-κB (NF-κB)and IL-13-STAT6- SAM pointed domain containing E26 transformation-specific transcription factor (SPDEF), as well as epithelial sodium channel (ENaC) and cystic fibrosis transmembrane conductance regulator (CFTR)], and signaling pathways related to mucus transport and excretion-ciliary beat frequency (CBF). Various inhibitors of mucus hypersecretion are in clinical use but have had limited benefits against COPD. Thus, novel therapies targeting airway mucus hypersecretion should be developed for effective management of muco-obstructive lung disease. Here, we systematically review the mechanisms and pathogenesis of airway mucus hypersecretion, with emphasis on multi-target and multi-link intervention strategies for the elucidation of novel inhibitors of airway mucus hypersecretion.

Endobronchial Valves for the Treatment of Bronchopleural Fistula and Pneumothorax Caused by Pulmonary Cryptococcosis in an AIDS Patient

Cryptococcal disease is an opportunistic infection that occurs primarily among people with advanced HIV disease and is an important cause of morbidity and mortality. Spontaneous pneumothorax (SP) is rare in acquired immune deficiency syndrome (AIDS) patients with pulmonary cryptococcosis (PC), but when it occurs, rapid and effective treatment is crucial to the prognosis, with mortality rates varying from 30 to 60%. SP is related to pneumonia mainly due to bacterial infections and pneumocystic jirovecii pneumonia (PJP). However, SP caused by PC is rare. When it occurs, it is often fatal and refractory, which is a challenge both for patients and clinicians. Here, we report a case of SP during the treatment of cryptococcal disease in a patient with AIDS. The pneumothorax remained despite chest tube drainage and evolved into a bronchopleural fistula that was confirmed by the Chartis system. The pneumothorax was significantly resolved following the placement of 2 endobronchial valves (EBVs). The patient tolerated the procedure very well and the pneumothorax gradually resolved. When immunocompromised patients suffer from refractory pneumothorax or prolonged air leaks, EBV implantation may be a feasible and minimally invasive procedure for this vulnerable population.