[Unilateral reduction of lung volume by application of intrabronchial valves on patients selected after endoscopic collateral ventilation assessment].

BACKGROUND

Endoscopic collateral ventilation assessment (ECVA) can be used to select patients suffering from emphysema for application of valves to achieve a reduction of lung volume. The objective is to obtain a post-operatively minimal clinically important improvement of the selected patient's physical capacity.

METHODS

Patients with severe chronic obstructive pulmonary disease (COPD) underwent examination for a possible reduction of lung volume. Those selected got ECVA. Patients whose collateral resistance (Rcoll) increased to Rcoll > 10 cm H2O/(mL/s) within a measurement duration of up to 300 s, were submitted to unilateral lobar application of intrabronchial valves (IBV). Differences in residual volume (RV) as well as distances in 6 minute walk tests (6MWT) between the time after application of valves (TX) and that before (T1) were calculated (TX minus T1).

RESULTS

Of a tested 310 emphysema patients, 17 met criteria allowing ECVA; 10 of 17 proved eligible for valve application. After 312 ± 170 days (TX - T1) the increase in walking distance was 44 ± 89.7 m; 7 of 10 patients achieved clinically relevant improvements (> 25 m). Differences in RV proved to correlate with differences in walking distances, but not yet with differences in measurement duration in ECVA.

CONCLUSIONS

Only a small portion of patients with progressive emphysema of the lung seem suitable for endoscopic reduction of lung volume by application of valves. Unilateral lobar application of IBV can result in durable, clinically relevant improvements of the patient's physical capacity. ECVA measurements should take a minimum of 300 s.