Supplementary Material for: Identifying Responders and Exploring Mechanisms of Action of the Endobronchial Coil Treatment for Emphysema

<b><i>Background:</i></b> 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. <b><i>Objectives:</i></b> 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. <b><i>Methods:</i></b> 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. <b><i>Results:</i></b> 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. <b><i>Conclusions:</i></b> 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.

<b><i>背景：</i></b> 迄今为止，已有3项随机对照试验（randomized controlled trials）证实，采用弹簧圈的支气管内植入治疗安全性与有效性均得到验证。然而，该治疗更为确切的潜在作用机制以及最佳疗效预测因子仍未明确。<b><i>目的：</i></b> 本研究旨在进一步阐明肺减容弹簧圈治疗（lung volume reduction coil treatment）的潜在生理学机制，并筛选出该治疗疗效的潜在预测因子。<b><i>方法：</i></b> 本研究为一项前瞻性非随机单中心研究，纳入接受双侧支气管内弹簧圈植入治疗的患者。所有受试者均于治疗前基线状态及治疗后3个月接受了多项全面的肺功能与体格检查。<b><i>结果：</i></b> 本研究共纳入24例患者（男性占比29%，平均年龄62岁，基线一秒用力呼气容积（forced expiratory volume in 1 s, FEV₁）占预计值百分比为26%，残气量（residual volume, RV）占预计值百分比为231%）。治疗后3个月，受试者的肺量测定指标、静态肺过度充气、空气潴留、气道阻力、治疗靶肺叶残气量及CT扫描下治疗肺叶空气潴留情况、运动耐量及生活质量均得到显著改善。残气量与气道阻力的变化与一秒用力呼气容积、用力肺活量（forced vital capacity, FVC）、空气潴留、最大呼气压力（maximal expiratory pressure）、动态顺应性（dynamic compliance）及动态肺过度充气的变化呈显著相关。基线状态下可用于预测该治疗疗效的指标包括：更高的残气量水平、更严重的空气潴留、治疗靶肺叶更高的肺气肿评分（emphysema score），以及更低的体力活动水平。<b><i>结论：</i></b> 本研究结果证实，肺气肿患者可从支气管内弹簧圈治疗中获益。该治疗的核心作用机制为通过改善气道阻力以降低静态肺过度充气，进而改善肺动态力学特性。但需精准筛选适宜患者人群方可获得治疗收益，此类患者应存在重度肺过度充气、严重空气潴留，且靶肺叶存在显著肺气肿。