Branches of the aortic arch in the cynomolgus macaque (Macaca fascicularis).

The aortic arch branching patterns of 49 male macaques (Macaca fascicularis) were described and classified according to the classification systems of DeGaris, and the incidence of each pattern was determined. The most frequent pattern observed was a two-branch type in which a truncus communis of intermediate length (7 to 11 mm) and the left subclavian artery constituted the only aortic arch branches. Five patterns not previously described in the cynomolgus were observed. Comparison of the cynomolgus and the rhesus macaques indicated a significant difference between the two species with the rhesus generally having a shorter truncus communis.