Anatomical variation in origin and course of the thoracoacromial trunk and its branches.

The variations in origin and course of the thoracoacromial trunk (TAT) and its branches were studied in 178 cadavers during the routine dissection from the year 1982 to 2002. The TAT originated from the first part of the axillary artery (AA) in 13.4% cases of the right and 10.6% of the left axilla. The variations in origin of the branches of TAT were divided into three groups. First variation group showed deltoacromial (DA) and clavipectoral (CP) subtrunks of the TAT originating directly from the AA in majority of cases. Second group revealed clavicular branch of the TAT originating from the AA, whereas in the third group all classical branches originated directly from the AA and there was no existence of the TAT. The superior thoracic artery (STA) originated from the TAT in 16.8% (Confidence Interval, CI: 11.12-21.89) cases of the right and 6.1% (CI: 2.59-9.53) of the left axilla and the lateral thoracic artery in 39.8% (CI: 32.01-46.10) cases of the right and 29.3% (CI: 15.01-26.80) of the left axilla. The incidence of variations in origin of the TAT and its branches was found higher on right side. The knowledge of these variations is of anatomical and surgical interest. This information is useful for the surgeons dealing with the axillary region especially in case of reconstructive surgery.