Comparison of physiological and radiological screening for lung volume reduction surgery

Physiological and radiological criteria are both used to identify candidate s for LVRS. This study compares the predictive value of these screening tec hniques among patients with homogeneous (Ho) and heterogeneous (He) emphyse ma. Preoperative inspiratory lung conductance (G(Li)) during spontaneous br eathing and quantitative radioisotope (V) over dot\(Q) over dot scan (QVQS) results were available for 48 of 50 patients undergoing bilateral LVRS for emphysema. Ho disease (n = 21) was defined by QVQS as an upper/lower perfu sion ratio (ULPR) between 0.75 and 1.25. GLi correlated with 6-mo improveme nt in FEV1 (Delta FEV1-6) (r = 0.53, p < 0.001) for the entire cohort, and for patients with both Ho (n = 21, r = 0.56, p = 0.015) and He disease (n = 27, r = 0.46, p = 0.017). ULPR correlated less well with <Delta>FEV1-6 (n = 48, r = -0.38; p = 0.008) for the cohort, and was significantly correlate d with outcomes only in the subgroup of patients with He disease (r = -0.40 , p = 0.04). Multivariate regression demonstrated that by combining Cu and ULPR criteria, 33% of the Delta FEV1-6 response could be accounted for. We conclude that both physiological and radiological criteria help identify ap propriate candidates for LVRS. G(Li) best identifies patients with Ho emphy sema who may benefit from surgery, but would be excluded on the basis of st rictly radiological criteria. ULPR helps identify patients with He disease that improves with surgery, despite unfavorable G(Li).