Fig. 3. Sample preoperative calculation of flap volume.

(A) Measurement of each part of the flap. The width of zones I and II was 7 and 5 cm, respectively, and the height of the skin island was 12 cm. The height of the adipose flap on the upper and lower sides of the transverse rectus abdominis myocutaneous (TRAM) flap was 4 cm. The thickness of zones I and II was 2.2 cm, on average; in this case, the thickness of zone I and II was 1.8 cm, and that of the adipose flap was 1.2 cm. (B) Calculated flap volume in zone I. The flap in zone I was approximated as a square prism (surrounded by the white line, length [12 cm] ×width [7 cm]×depth [2.2 cm]=184.8 cm³). (C) Calculated flap volume in zone II. The flap in zone II was approximated as a square prism (surrounded by the white line, length [12 cm]× width [X cm]×depth [2.2 cm]=26.4X cm³). (D) Calculated flap volume in zone III. The flap in zone III was approximated as a triangular prism (surrounded by the white line, length [12 cm]×width [5 cm]×depth [1.8 cm]× 0.5=54 cm³). (E) Calculated volume of the adipose flap. The upper and lower sides of the adipose flap were approximated as a square prism ([4+4 cm] ×[7+X+5 cm] ×1.2 cm=115.2+9.6X cm³), and the left side of the adipose flap was approximated as a triangular prism (12 cm ×5 cm ×1.2 cm ×0.5 =36 cm³). They are shown and surrounded by the white line.