The Perforasome Theory: Vascular Anatomy and Clinical Implications

Background: A clear understanding of the vascular anatomy of an individual perforator relative to its vascular territory and flow characteristics is essential for both flap design and harvest. The authors investigated the three-dimensional and four-dimensional arterial vascular territory of a single perforator, termed a "perforasome," in major clinically relevant areas of the body.

Methods: A vascular anatomy study was performed using 40 fresh cadavers. A total of 217 flaps and arterial perforasomes were studied. Dissection of all perforators was performed under loupe magnification. Perforator flaps on the anterior trunk, posterior trunk, and extremities were studied. Flaps underwent both static (three-dimensional) and dynamic (four-dimensional) computed tomographic angiography to better assess vascular anatomy, flow characteristics, and the contribution of both the subdermal plexus and fascia to flap perfusion.

Results: The perfusion and vascular territory of perforators is highly complex and variable. Each perforasome is linked with adjacent perforasomes by means of two main mechanisms that include both direct and indirect linking vessels. Vascular axis follows the axiality of linking vessels. Mass vascularity of a perforator found adjacent to an articulation is directed away from that same articulation, whereas perforators found at a midpoint between two articulations, or midpoint in the trunk, have a multidirectional flow distribution.

Conclusions: Each perforator holds a unique vascular territory (perforasome). Perforator vascular supply is highly complex and follows some common guidelines. Direct and indirect linking vessels play a critical part in perforator flap perfusion, and every clinically significant perforator has the potential to become either a pedicle or free perforator flap.