Diaphragm dimensions after single-lung transplantation for emphysema

We used three-dimensional reconstructions obtained with spiral computed tom ography to measure total diaphragm surface area (A(di)), and the surface ar ea of the dome (A(do)) and of the zone of apposition (A(ap)) of the diaphra gm in nine patients with single-lung transplantation (SLT) for emphysema an d nine normal subjects matched for age, sex, height, and weight. Measuremen ts were obtained at supine FRC, midinspiratory capacity, and TLC. In the no rmal subjects, A(do) and A(di) were greater on the right than on the left s ide, and the right dome was positioned more cranially than the left one, pr esumably because of the presence of the liver. Compared with either the ips ilateral side in the controls or the native side in the patients, A(do) was smaller on the transplanted side because the mediastinum was shifted towar d the graft. A(di) showed a similar trend. On the other hand, the radius of curvature of the dome in the coronal and sagittal planes was similar on th e side of the graft and on the ipsilateral side in the controls. In conclus ion, we found that after SLT for emphysema, diaphragm configuration comes b ack to normal but A(do), and with it A(di), remain smaller than in normal s ubjects because the mediastinum is displaced toward the graft.