[Vascularization of the human adult sternum (author's transl)].

The study of the vascularization of the sternum allows to individualise the vascular pedicles, the anterior and posterior peripheral sternal networks and the intrasternal vascularization. 1. The numerous vascular pedicles of the sternum all come from the internal mammary arteries. The postero-superior and postero-inferior sternal arteries of one simple intercostal space or of contiguous spaces are anastomosed by systems of latero-sternal, retroarticular and retro-sternal arches. From these arches come vessels which go directly to the sternum or which form the posterior peripheral sternal network. The anterior sternal branches of perforating arteries form arches or go directly to the anterior peripheral sternal network or to the sternum. The veins are less anastomosed than the arteries and therefore their arches are less distinct. 2. The anterior and posterior peripheral sternal networks are especially developed with respect to the lower half of the body of the sternum at the level of the 4th and 5th intercostal spaces. The posterior network is more developed than the anterior network. The arteries often have a spiral course, their anastomoses occur with their contralateral and homolateral homologues. The veins, which are of larger calibre than the arteries, design a denser and more irregular network. 3. The intra-skeletal vascularization, tributary of the peripheral networks, arches and branches of the internal mammary vessels, includes a network of the compact bone and a medullary network. The network of the compact bone, situated in one plane, is composed of polyhedral elongated meshes, according to the large axe of the sternum. The medullary network may be divided into a sub-cortical and a centro-medullary part. The sub-cortical part is composed of a peripheral zone and a more central zone. The totality of the intramedullary network includes a few fine arteries, an interadipocytary network, which is very developed and is variable in form. It also include sinuses of increasing order connected into the venous system, into the network of the compact bone, or into the large trans-cortical veins, which are drained by the peripheral sternal networks or by the collateral veins or the internal mammary system.