A Systematic Study of Vascular Distribution Characteristics and Axis Design of Various Flap Types.

BACKGROUND The aim of this study was to define blood flow characteristics of multiple types of flaps and the theoretical basis of flap axis design. MATERIAL AND METHODS Sixty Sprague-Dawley (SD) rats were randomly divided into 6 groups: a normal skin group, and 5 groups with different types of flap: abdominal flap group, dorsal flap group, single-perforator flap group, double-perforators flap group, and delayed cutaneous nerve flap group. The vascular distribution characteristics of normal skin and various flap types were observed by gross morphology of specimens and X-ray after perfusion. RESULTS There were distinct differences in vascular anastomosis and density in dorsal and ventral SD rats. The area of flap survival in the dorsal flap group was superior to that in the abdominal flap group, but the flap axis of the 2 groups passed straight through the middle of the pedicle. The flap surviving area in the double-perforators flap group was remarkably larger than in the single-perforator flap group, while the flap axis in the single-perforator flap group passed straight through the perforators, and in the double-perforators flap group there was a linking vessel between the 2 perforators. There were linking and reticulate vessels, in addition, linking vessels and cutaneous nerves were concomitant in the delayed cutaneous nerve flap group. The flap axis was the travel route of the cutaneous nerve. CONCLUSIONS Variations in flap blood supply patterns and axes with alterations based on flap types have implications for flap survival. Understanding blood flow characteristics within each flap type and accurately designing the flap axis is essential for flap survival.