Why Is the Perforator Flap Opaque? Consideration From the Perspective of Tissue Composition Based on a New Skin Flap Classification

Despite the clinical importance of perforator flaps in the field of flap surgery, ambiguity still surrounds the terminology and definition. This study aimed to resolve this ambiguity through a logical analysis of perforator flaps. In this study, we present a new classification system for skin flaps with various tissue compositions based on the vascular plexus we have previously clarified and examine whether perforator flaps constitute an independent category from the perspective of tissue composition. Through anatomical and physiological analyses, we identified 7 distinct skin flap types: full-thickness, split-thickness, thin (including the super-thin and pure skin subtypes), dermis, adipofascial, protective adipofascial, and lubricant adipofascial flaps. All perforator flaps except for the pure skin perforator flap do not exhibit tissue compositions exclusive to their type and, therefore, cannot be considered a distinct category based solely on tissue structure. We discussed the need for rethinking the classification not only in terms of the surgical technique, but also based on objective anatomical features such as tissue composition and vascular connectivity. By focusing on these criteria, this new classification system further clarifies and homogenizes the terminology and conceptual framework of skin flap surgery.