The role of the internal thoracic artery in the sternal blood supply

The altered arterial supply to the sternum after use of the internal thoracic artery in coronary bypass surgery was studied by delineation of the sternal arterial system with plastic material and by injection of ink/barium contrast for radiography and microscopy. The study was performed on 17 anterior chest walls from human cadavers. The total arterial supply was charted before and after ‘harvest’ of the internal thoracic artery. The dominant blood supply to the sternum was found to be periosteal and derived almost exclusively from branches of the internal thoracic artery. Following harvest of that artery, the arterial supply to the upper part of the corpus sterni was compromised, and based only on sparse ramifications to the periosteal membrane from the thoracoacromial artery via branches from the pectoralis major muscle.