Lung volume reduction surgery primarily increases vital capacity by reducing RV more than TLC. As the chest wall is the major TLC limiting factor, an alternative approach that could circumvent size mismatch would be a surgical enlargement of the thorax cavity. Any post-operative increase of TLC would allow greater dynamic operational lung volumes to occur with an equal amount of dead space. Moreover, resizing of the thorax would have a tremendous advantage over resizing of the lung, in that it would not require resection of the lung in patients in whom lung tissue is already scarce. Chest expansion will only be guaranteed if the sternal widening osteotomy will obtain a solid union. Small poly-ether-ether-keton (PEEK) cages were designed to match both sternal halves in a 'press fit' way, which were filled with lyophilised bone and fixed with extra wires as in a classical sternotomy. These bone-filled cages function as a perfect matrix for progressive in-growth of cancellous bone.
