Interest in assessment of collateral flow measurement has resurfaced with the advent ofendoscopic lung volume reduction (ELVR) trials-namely valve technology that relies onatelectasis to achieve volume reduction. It is currently thought that collateral ventilation (CV) isresponsible for ELVR failures, as occluded lobes can backfill through these channels. We arereporting on the use of catheter based device used to measure pressures flow and calculateresistance in vivo.
Patients indicated for ELVR were included prospectively. All investigations were performed under local anesthesia plus moderate sedation under spontaneous breathing. The lobes targeted for ELVR were blocked via catheter system (Chartis, Pulmonx, Pal Alto, CA) and pressure and flow were assessed continuously. The results, the quality of the measurements and complications were documented as the end points of the trial.
From 06/2008 to 11/2008, 25 patients were examined. In all patients the assessmentfor pressure and flows could be performed without any complications. No adverse events occursin any of the 25 patients. The end point of this prospective trial was thecorrelation of the measurements with the event of atelectasis after placement of the endobronchialvalve (EBV) used for the ELVR procedure. An atelectasis occured in 5 cases after ELVR, in four cases the chest X-ray showed a dystelectasis. In five patients an evaluation of the pressure andflow was not possible due to user error. In 18 patients, the resistance measurements directly correlated with the chest X-ray atelectasis result made after placement of the endobronchial valve (EBV). Only in two patients, there was a mismatch between the collateral flow measurement and the incidence of atelectasis after placement of EBV. In conclusion, in 18 of 20 patients (90 %) a correlation could be detected.
Measurement of airway pressures and flows in various lobes were safley and succesfully achieved.
A correlation of Chartis measurements with the event of atelectasis after EBV placement was found in 90 % of the analyzable cases. The clinical impact of these measurements will need to be evaluated in subsequent trials.
Ralf Eberhardt, No Financial Disclosure Information; No Product/Research Disclosure Information