THE ANATOMY OF THE LOWER SERRATUS ANTERIOR MUSCLE - A FRESH CADAVER STUDY

Forty fresh cadaver dissections were studied to determine Variations i n the anatomy of the lower portion of the serratus anterior muscle. In all cases, the lower three to five slips of the serratus anterior mus cle were supplied by one to three branches from the thoracodorsal arte ry, the so-called serratus branches. Three vascular patterns were iden tified: type I with one branch (40 percent), type II with two branches (50 percent), and type III with three branches (10 percent). The mean dimensions of the lower serratus anterior flap were 18.0 X 9.0 cm (ra nge 12.0 X 8.0 cm to 21.0 X 15.0 cm). The mean pedicle length was 11.3 +/- 2.8 cm (range 7.3 to 13.3 cm). A crow's foot landmark has been id entified to facilitate flap dissection. This landmark marks the junctu re of the long thoracic nerve and the dominant serratus branch. This j uncture can be found at the superior border of the sixth or seventh ri b. The lower serratus anterior flap is ideal for reconstruction of sma ll to moderate-sized defects because of its flat, broad dimensions and its long vascular pedicle.