Quantitative assessment of emphysematous parenchyma using multidetector-row computed tomography in patients scheduled for endobronchial treatment with one-way valves†

To investigate the role of volume quantitative assessment using multidetector-row computed tomography to select patients scheduled for endobronchial one-way valves treatment.

Twenty-five consecutive patients (15 with heterogeneous emphysema and 10 with giant emphysematous bulla) undergoing endobronchial valves treatment were enrolled. All patients were studied pre- and postoperatively with standard pulmonary functional tests and quantitative volume assessment of target lobe and entire lung. Emphysematous parenchyma was obtained applying density thresholds of -1.024/-950 Hounsfield units. Among different subtype of patients, we evaluated: (i) the differences between preoperative versus postoperative data; (ii) the correlation between functional and volumetric quantification changes and (iii) the critical threshold value of volumetric quantification of the target lobe in close association with clinical effects.

Among heterogeneous emphysematous and giant emphysematous bulla patients, a significant improvement of flow-expiratory volume in 1 s (from 36.9 ± 15.3 to 43.9 ± 10.4; P = 0.01; and from 35.8 ± 6.0 to 47.5 ± 7.9; P < 0.0001, respectively); and of forced vital capacity (from 41.9 ± 5.9 to 47.3 ± 9.3; P = 0.0009 and from 40.7 ± 5.9 to 48.8 ± 4.9; P = 0.0002, respectively); and a significant reduction of residual volume (from 185 ± 14 to 157 ± 14.7; P = 0.005; and from 196 ± 13.5 to 137 ± 21; P < 0.0001, respectively) and of total lung volume (from 166.7 ± 13 to 137 ± 18 ; P = 0.0003, and from 169 ± 15 to 134 ± 18; P < 0.0001, respectively) were seen after treatment. The volumetric measurements showed a reduction of volume of the treated lobe among heterogeneous emphysematous patients (from 1448 ± 204 to 1076 ± 364; P = 0.0008); and in those with giant emphysematous bulla (from 1668 ± 140 to 864 ± 199; P < 0.0001). The entire lung and target lobe volume changes were inversely correlated with change in forced expiratory volume in 1 s in patients with heterogeneous emphysematous (r = -0.7; P = 0.0006; and r = -0.7; P = 0.0009, respectively) and giant emphysematous bulla (r = -0.8; P = 0.001; and r = -0.7; P = 0.009, respectively). Among patients with heterogenous emphysematous and giant emphysematous bulla, the value of sensitivity and specificity were 66.6 and 83%, respectively (for a volumetric qunatification >1.5239), and of 60 and 100%, respectively (for a volumetric qunatification >1.762).

Our study showed that the volumetric quantification adds further informations to the routine evaluation for optimizing the selection of patients scheduled for endobronchial valve treatment.