When can computed tomography-fissure analysis replace Chartis collateral ventilation assessment in the prediction of patients with emphysema who might benefit from endobronchial valve therapy?

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was when can computed tomography-fissure analysis replace Chartis collateral ventilation assessment in the prediction of patients with emphysema who might benefit from endobronchial valve therapy? Twelve papers were chosen to answer the question. The authors, date, journal, country of publication and study type; patient group studied; relevant outcomes and results of these papers were tabulated. Five studies retrospectively compared the prognostic value of 2 methods. They found that when computed tomography-fissure analysis showed an intact fissure more than 95%, both methods were equivalent in correctly predicting a positive response to valve therapy. Concordant results were found in two-thirds of patients, and the additional evaluation with Chartis did not confer a significant advantage. Yet the increasing cost and time to procedure, the different ranges of Chartis findings patterns not correlated with lung volume reduction and the unfeasibility of the measurements (reported in 6-17% of the most series) due to difficult anatomy are additional limitations for its use. Conversely, in patients with fissure integrity between 75% and 90%, Chartis assessment could improve the patient selection, because the computed tomography-fissure analysis alone is unable to predict a successful treatment. In this situation, Chartis had a 31% ability to predict those patients who can be successfully treated. In BeLieVer-HIfi Study, post hoc analysis revealed that the additional use of Chartis for patient selection significantly improved outcomes. Similarly, STELVIO, LIVE and IMPACT studies, where only patients with complete fissure and negative Chartis measurement were treated, showed significant benefits after valve treatment. Finally, in patients with fissure integrity below 75%, the negative predictive value for lobar atelectasis is 100%. Thus, in these patients, it could be futile even considering a Chartis assessment.