Limited Benefit of Additional Chartis® Assessments for Collateral Ventilation Evaluation in Patients with Software Quantified Intact Target Lobe Fissure – Results from a Retrospective Analysis of the German Lung Emphysema Registry

Jacopo Saccomanno,1 Thomas Sgarbossa,1 Konrad Neumann,2 Franz Stanzel,3 Stefan Andreas,4,5 Stephan Eisenmann,6 Bernd Schmidt,7 Wolfgang Gesierich,8 Martin Witzenrath,1,5,9 Ralf Harto Hübner1 On behalf of the Lung Emphysema study group1Department of Infectious Diseases, Respiratory Medicine and Critical Care, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität Zu Berlin, Berlin, Germany; 2Institute of Biometry and Clinical Epidemiology, Charité - Universitätsmedizin Berlin, Berlin, Germany; 3Department of Respiratory Medicine, Lungenklinik Hemer, Hemer, Germany; 4Zentrum für Pneumologie, Lungenfachklinik Immenhausen, Immenhausen, Germany; 5German Center for Lung Research (DZL), Berlin, Germany; 6Department of Respiratory Medicine, Universitätsklinikum Halle, Halle, Germany; 7Department of Internal Medicine – Respiratory and Sleep Medicine, DRK Kliniken Berlin Mitte, Berlin, Germany; 8Department of Respiratory Medicine, Asklepios Lungenklinik Gauting, Gauting, Germany; 9Capnetz Foundation, Hannover, GermanyCorrespondence: Jacopo Saccomanno, Department of Infectious Diseases, Respiratory Medicine and Critical Care, Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Hindenburgdamm 30, Berlin, 12203, Germany, Email [email protected]: Endoscopic lung volume reduction (ELVR) with valves is a treatment option for selected patients with emphysema. Collateral Ventilation (CV) is measured directly with the Chartis® bronchoscopic assessment system (PulmonX Inc. Redwood City, CA, USA) and indirectly via fissure completeness score (FCS) on computed-tomography (CT). It remains unclear, whether the additional Chartis® assessment improves treatment outcome when the target lobe shows intact fissure (FCS ≥ 95%).Study Design and Methods: This retrospective analysis used data from the German Lungenemphysemregister e.V. a prospective multicenter trial on lung volume reduction therapy. Patients with an intact fissure (FCS ≥ 95%) of the target lobe undergoing ELVR were included. Treatment outcomes were compared between patients who had a Chartis® measurement prior to ELVR and those who did not.Results: A total of 262 patients were analyzed: 175 with Chartis® and 87 without. Baseline parameters were comparable between groups. At 3-month follow-up significant improvements in lung function parameters (FEV1, RV, DLCO, pCO2), exercise capacity (6-MWT) and quality of life parameters (SGRQ, mMRC and CAT) were seen in both groups. Treatment efficacy at 3-month follow-up was comparable in patients regardless of previous Chartis® measurements. Furthermore, there was no difference in treatment outcome, when comparing improvements for the right and left lung separately. Responder rates were similar between the groups, with a comparable MCID in both. Complication rates were also largely comparable, except for a higher pneumothorax rate in the no-Chartis group (7% vs 22%).Discussion: This analysis did not find evidence that a Chartis® assessment provided additional benefit to the treatment response after ELVR at 3-month follow-up in patients with an intact fissure of the target lobe with an FCS ≥ 95%. These findings may be clinically relevant as they suggest that additional invasive Chartis® measurement might be dispensable in this subgroup.Keywords: Lung emphysema, endoscopic lung volume reduction with valves, collateral ventilation, COPD