Abstract
Introduction: Impaired MCC contributes to the symptoms and pathophysiology of COPD. MCC from the large airways has been imaged in two dimensions and measured by Tracheal Mucus Velocity (TMV), and is reduced in patients with COPD (Morgan et al, ERJ 2004).
Aim: To image MCC in the trachea in 3-D to accurately map mucus dynamics, as a prelude to assessment pharmacological intervention on TMV in COPD.
Methods: 20 patients with mild-moderate COPD (mean FEV1=67%) participated. Patients were imaged after a 7-day washout of their LAMA and LABA, and on day 2 after a dose of Indacaterol. A droplet of 0.1mL radio-labelled albumin (Tc MAA) was injected through the crycothyroid membrane with the patient sitting at 45 degrees. Injection was followed immediately by a 15min acquisition under the gamma camera which captured lateral and AP images every 30 seconds. Frame by frame analysis was then used to visually assess movement.
Results: Radio-label was successfully deposited down the length of the trachea in 39/40 studies. 38/39 traces cleared antegrade. Of these in 35 clearance was clearly in a right handed spiral, while in 3 the direction of spiral was indeterminate. In 27/39 clearance was in a continuous trail, while in 12 the mucus separated and re-coalesced as it cleared. Indacaterol did not effect the pattern mucous clearance. Two patients experienced mild bruising at the site of injection.
Conclusion: Imaging of mucus clearance in two planes allows accurate mapping in three dimensions. This led to the novel finding that mucous clearance normally spirals as it moves up the trachea.
- Copyright ©ERS 2015