Quantitative difference of acute intraoperative expansion in various body regions

OBJECTIVE: To investigate the efficacy of intraoperative sustained limited expansion (ISLE) by examining the ex vivo biomechanical properties of acutely expanded skin flaps. MATERIALS AND METHODS: Fourteen fresh male cadavers were tested. On both sides of each cadaver, a 4 × 10 cm, the laterally based flap was raised at the external auditory canal of the scalp and a 15 × 8 cm, the proximately based flap was raised at the lateral arm, anterior thorax, and lateral thigh. For each body region, a flap on one side was subject to acute intermittent expansion, while the corresponding contralateral flap served as the control. Both control and acutely expanded flaps underwent stepwise loading to assess their biomechanical properties. RESULTS: No dimensional changes were observed in the acutely expanded flaps when compared to the controls. Mean stiffness and strain values were not significantly different from control values for flaps raised on the scalp, but statistically significant changes were found for those on the lateral arm, anterior thorax and lateral thigh (p < 0.05). CONCLUSIONS: ISLE produced statistically significant biomechanical improvements when applied to the flaps raised on the arm, thorax and thigh, leading to a significant gain in compliance. We suggest that the ineffectiveness of ISLE, when applied to scalp flaps, was due to the inelasticity of the galea aponeurotica. Our findings confirm the general effectiveness of acute skin expansion as means of reducing wound-closure tension after large skin excisions; at least in regions other than the scalp.