A Multi-center RCT to Evaluate Subsegmental BTVA Treatment for Severe Emphysema

"Patients in experimental group will be treated with the InterVapor System in at least 2 subsegments of different segments(unless the two most severe subsegments are located in the same segment). Patients in control group will be treated with the InterVapor System in at least 1 segment.~A sequential procedure allows for at least 6 weeks and no longer than 6 months after the first procedure. Patients in both groups will receive ipsilateral hemithorax treatment per procedure, with a treatment volume (air + tissue) of ≤1700 mL per procedure and ≥1000 mL cumulatively across two procedures. All patients will continue to receive optimal medical therapy (GOLD guidelines) for the duration of the study.~Follow-up visits will be scheduled at 1, 3, 6 and 12 months following the second procedure with examination of pulmonary function tests, HRCT, 6-minute walk test, SGRQ-C, mMRC, CAT questionnaires. All adverse events during the study will be recorded."