Objective

To assess baseline data in a cohort of patients that have undergone endo-bronchial valve (EBV) insertion to treat severe emphysematous COPD and to compare those with evidence of radiological response to those that did not respond in order to inform future patient selection for procedure.

Methods

Retrospective analysis of patients undergoing EBV insertion. Fissure completeness assessed with high resolution thoracic CT. Patients with fissure completeness >80% underwent EBV insertion. Responders defined as those with complete (100%) or partial (>50%) collapse of the target lobe at 4-6 week follow up. Baseline data included age, gender and lung function tests. Flow analysis using endo-bronchial flow catheter (Chartis) was included in the analysis. Alpha 1 anti-trypsin deficiency was noted.

Results

25 patients, mean age 63 years and FEV1 29.9% predicted, were included. 14 had complete radiological response, 2 partial response and 9 no response. 5 patients had alpha1 anti-trypsin deficiency (A1AD). 2/16 responders had bullous emphysema compared to 7/9 non-responders (p=0.002). A decline of flow over time (marker of absence of collateral ventilation) on Chartis analysis was seen in 9/10 of the responders and in 2/7 non-responders (p=0.035). Only 2 out of 5 patients with A1AD responded to therapy.

Conclusion

This analysis identified that even with fissure completeness; patients with significant bullae of the target lobe may be more at risk of failure from EBV treatment. This data differs from another study where patients with giant emphysematous bullae appeared to benefit more from EBV implantation. The use of the Chartis Pulmonary Assessment SystemTM to identify patients for EBV therapy is a useful predictor of response to treatment. Alpha1 anti-trypsin deficiency is associated with low response.