Quantitative benefits provided by acute tissue expansion: a biomechanical study in human cadavers.

The aim of this study was to test the ex vivo biomechanical properties of acutely expanded cutaneous flaps to quantitatively assess the efficacy of intraoperative tissue expansion. A total of 14 fresh male cadavers were used for the study. In each cadaver, a rectangular (15 x 8 cm), proximally based flap was designed on each side of the body, in three different locations: lateral arm, anterior thorax, anterior thigh. In each cadaver, one randomly selected flap per each body region underwent acute-intermittent expansion, whereas the contralateral flap served as control. The biomechanical properties (stress/strain ratio, mean stiffness) of both expanded and control flaps were then assessed by means of a dynamometer and a force-transducer. The obtained data showed that the biomechanical benefits provided by acute tissue expansion were statistically different (P< 0.05) from those obtained by simple subcutaneous undermining. While no changes of length have been observed in the acutely expanded skin flaps as compared to control cutaneous flaps, a statistically significant gain in the compliance of the former has been recorded as compared to the biomechanical behaviour of the latter.