Contraction of skin flaps: re-examining the scientific basis

Abstract

Contraction in a skin flap is unavoidable after it is raised because of its elastic content and despite the best of planning a flap may fall short which may lead to some necrosis. This study was conducted to ascertain the extent of contraction of flaps and the factors that might influence this contraction. This prospective study included 25 patients who underwent reconstructions of defects with different types of skin and fascio-cutaneous (FC) flaps. Clinical data including age; sex; body mass index; site/type of flap; and the flap’s surface area, thickness, and its contraction in relation with the relaxed skin tension lines (RSTL) were recorded and analyzed. The outcome of the success or failure of the flap was ascertained by clinical examination. There were 20 males and 5 female patients and their age ranged from 10 to 67 years. Mean flap contraction was 20.01% in skin flaps and 20.38% in FC flaps; overall mean contraction was 20.19%. Flaps retracted more when constructed parallel to RSTL, in females and in patients with high BMI. Age did not affect the contraction. Skin flaps can be stretched to a certain extent, but not up to pre-flap area without compromising the blood supply. Therefore, adequate allowance should be provided to avoid stretching, and subsequent necrosis and dehiscence. The most practical way of providing this allowance is by planning in reverse which flap size is always bigger than the defect, therefore providing margins for flap contraction. Level IV, risk/prognostic study