Bronchial Rheoplasty Increases Distal Airway Volume in Chronic Bronchitis

Abstract

Background: Bronchial Rheoplasty is a novel bronchoscopic therapy for chronic bronchitis (CB) which uses pulsed electric fields to ablate mucus producing cells in the airways to reduce excess mucus production and inflammation. Functional respiratory imaging (FRI) has been used to assess lobar and total lung volumes, airway counts, volumes and resistance. The effects of Bronchial Rheoplasty on total airway count (TAC) and distal airway volume (DAV) assessed by FRI are unknown. We hypothesized that Bronchial Rheoplasty would increase DAV and TAC in CB patients by decreasing airway mucus obstruction and inflammation.

Methods: We conducted a retrospective analysis of 27 CB patients enrolled in the first clinical trial of Bronchial Rheoplasty. Lung function tests, SGRQ, and CAT scores were obtained at baseline and 3 months post-intervention. FRI was performed at baseline and at 3 months after completion of bilateral Rheoplasty. DAV and TAC were compared pre- and post-intervention using paired t tests.

Results: DAV pre- and post-Rheoplasty were 8.87±5.09mL and 10.82±6.92mL, respectively (mean diff 1.95mL, 95% CI 0.66, 3.23, p=0.005, 21.9% increase). Similar trends were seen in TAC (pre- and post-Rheoplasty 115.6±44.8 airways and 131.2±59.9 airways, mean diff 15.7 airways, 95% CI 1.4, 30.0, p=0.033, 13.5% increase). Changes in DAV and TAC were accompanied by improvements in SGRQ (-17.2±20.0 points, 95% CI -24.9, -9.6, p<0.0001) and CAT scores (-8.9±7.6 points, 95% CI -11.8, -6.1, p<0.0001).

Conclusions: Bronchial Rheoplasty resulted in increased DAV and TAC, likely due to a reduction in mucus obstruction allowing for greater distal ventilation. These changes were accompanied by improvements in quality of life.