Pedicled skin-flaps: The fallacy of the length: Width ratio

Abstract

The viable length of a skin-flap is said to depend on the width of its pedicle. This is one of the established principles of plastic surgery, which is often quoted and never questioned. It was not intended to question this principle when the surviving lengths of flaps of different widths were measured in the pig. The intention was to correlate survival with the appearance after injection of an intravital dye. Flaps were made of different widths to spread the range of observations. The results were unexpected; surviving length was not directly proportional to width. Elaboration of this relationship, by experimental and mathematical methods, forms the subject of this paper. The old concept of a length: width ratio gradually evolved into a new one: that flaps made under similar conditions of blood-supply survive to the same length regardless of width. The steps of this change in concept will be presented.