Variations of thoraco-abdominal volumes and configuration after lung transplantation measured by opto-electronic plethysmography

Lung transplantation is the established surgical therapy for pulmonary end-stage disease. Although the pulmonary function after lung transplantation is well studied, variations of thoraco-abominal volumes and configuration remain uninvestigated. The aim of this study is to investigate if lung transplantation has any effect on the volume of the chest wall and its different compartments. In thirteen patients (8 cystic fibrosis, CF, 5 pulmonary fibrosis, PF), volumes of the entire chest wall (Vcw), pulmonary rib cage (Vrcp), abdominal rib cage (Vrca) and abdomen (Vab) were measured by opto‐ electronic plethysmography (OEP) in seated position during spontaneous quiet breathing and slow vital capacity maneuver before and after (xx±yy weeks) lung transplantation (double in CF, single in PF). On the same occasions, pulmonary function tests were also performed. Our results indicate a rearrangement of thoraco-abdominal volumes after double lung transplantation, namely a decrease of abdominal volume, suggesting a less flattened diaphragm. The lower rib cage becomes slightly larger, probably due to the re‐accomodation of the diaphragm and the resultant larger portion of this compartment submitted to abdominal pressure. The pulmonary rib cage decreases, probably due to the lower degree of lung hyperinflation. Conversely, after single lung transplantation no significant changes in chest wall volumes are observed.