Objective: Many skin flaps have been described for fingertip reconstruction; however, they have not been compared histologically. The aim of this study is to compare the histological features of common insensate flaps that are used for fingertip reconstruction.
Method: Skin from fingertips and common flap donor sites on the hand and forearm of cadavers were harvested. This study investigated four histological characteristics, namely thickness of the epidermis and dermis; the ratio of collagen to elastic fibres (C/E ratio) in subdermal tissues, and distribution densities of Merkel cells and Meissner's corpuscles. It then compared the values obtained to determine which flap donor site best matched the fingertip.
Results: Epidermal thickness of the reverse digital artery island flap, thenar flap, and hypothenar flap was similar to that of fingertip tissue; dermal thickness of the hypothenar flap was similar to that of fingertip tissue. The C/E ratio of the reverse digital artery island flap was similar to that of fingertip tissue. Merkel cells were abundant in the reverse digital artery island flap, but Meissner's corpuscles were few in each of the flaps compared with fingertip tissue.
Conclusion: The flap donor site with histological properties most similar to fingertip tissue was the palmar lateral aspect at the finger base, representative of the reverse digital artery island flap with respect to epidermal thickness, C/E ratio, and presence of Merkel cells. The thenar and hypothenar flaps also showed similar properties.
Keywords: Fingertip reconstruction; Meissner’s corpuscle; Merkel cell; insensate flap; skin thickness.