Airway Mucus Plugging in Chronic Bronchitis and the Impact of Bronchial Rheoplasty.

Abstract

Chronic bronchitis (CB) is characterized by excessive airway mucus production. Mucus plugs occluding the airway are common in CB, are associated with increased all-cause mortality, and can be identified on CT imaging. Does bronchial rheoplasty (BR) reduce mucus plugging (MP) evident on CT imaging by basket catheter expansion and delivery of pulsed electric fields to the airway mucosa? Fifty-five patients with symptomatic CB (COPD Assessment Test cough and phlegm scores, ≥ 7 of 10) underwent bilateral BR procedures with CT performed before and 6 months after completion of the BR procedure. MP was calculated as the number detectable by CT imaging in each of 18 lung segments. Total airway count, distal airway volume (DAV; air volume within identifiable airways beyond the segmental level), and disconnected DAV (branches appearing to be disconnected from airway-occluding mucus) were assessed. Patients with significant CB symptoms were grouped by the presence or absence of MP at baseline. Most patients, 36 of 55 (65%), exhibited at least 1 lung segment with MP before the intervention. Notably, nearly one-third of patients (35% [19/55]) did not have MP noted on baseline imaging, despite significant self-reported CB symptoms. In patients with lung segments with MP at baseline, the mean segmental MP score was reduced by approximately 1 segment (mean [SD], -0.90 [0.33]) at follow-up from 4.3 (4.0) segments to 3.4 (3.7) segments (P = .0392), with more than one-half of patients (52.8% [19 of 36]) improving by ≥ 1 segment. Correspondingly, disconnected DAV also increased at follow-up by 16.0% (89.8%). Most patients without baseline MP (63% [12 of 19]) remained without MP at follow-up. In this study, patients with CB who demonstrate MP on CT imaging experienced a significant mucus plug reduction at 6 months after BR, consistent with changes in patient-reported symptoms. These findings warrant further investigation. Australian New Zealand Clinical Trials Registry; No.: ACTRN 12617000330347; URL: www.anzctr.org.auClinicalTrials.gov; Nos.: NCT03107494, NCT03385616, NCT03631472; URL: www. gov.