Reappraisal of the anatomy of the accessory internal thoracic artery

Abstract

The accessory internal thoracic artery (AITA) is a variably large branch of the initial portion of the internal thoracic artery (ITA). The AITA has been neglected as an important anatomical structure and has been identified as the culprit for the “steal-syndrome” of coronary blood flow after the use of the ITA in coronary artery revascularisation. A cadaveric study of 50 cadavers was performed to investigate the occurrence of the AITA. We found 10 (20%) out of the 50 cadavers examined, presented with AITAs either bilaterally (4%) or unilaterally (16%). Five of the eight unilateral specimens showed a left-sided appearance of the AITA. Fourteen percent of the AITAs were found in cadavers of Mixed-race (Coloured) and 6% in individuals of African descent. Knowledge of the AITA is essential for any thoracic surgeon, during the preparation of the ITA for coronary revascularisation. Data from this study supports the notion that the AITA is a highly variable structure with little correlates based on ethnicity. The AITA appear to be found more often on the left in unilateral specimens.

Key Words: Accessory, Internal Thoracic artery