Thickness of skin and subcutaneous tissue of the free flap donor sites: A histologic study

Purpose The aim of this study is to compare the thickness of skin and hypodermis of the free flap donor sites. Methods In 12 cadavers, specimens were harvested from donor sites of radial forearm flap (RF), anterolateral thigh flap (ALT), thoracodorsal perforator flap (TD), and deep inferior epigastric perforator flap (DIEP). Tissues were stained with Masson-trichrome. Results The thickness of the epidermis ranged 32–42 μm according to the donor sites. The thickness of the dermis ranged 949–1,350 μm. The dermis of the TD (2,152 ± 575 μm) was the thickest. The thickness of the hypodermis ranged 1,913–7,105 μm. The hypodermis of the DIEP (7,105 ± 4,543 μm) was the thickest followed by the ALT (6,012 ± 4,092 μm) and TD (4,688 ± 1,905 μm). The dermis (949 ± 311 μm) and the hypodermis (1,913 ± 1,066 μm) of the RF were the thinnest. As the thickness of the dermis increased, the thickness of the hypodermis also increased. Conclusion Thin hypodermis was found in radial forearm flap and thoracodorsal perforator flap donor sites, which may be used for reconstruction of thin defects. © 2015 Wiley Periodicals, Inc. Microsurgery, 2015.