Anatomical Study of Perfusion of a Periosteal Flap with a Lateral Pedicle

Background: Pedicled periosteal flaps are commonly used for tissue defects between the base of the skull and the midfacial area. This study aimed to clarify the 3-dimensional vascular distribution of temporal region flaps. Methods: Ten fresh cadavers were used. Full-thickness cranial flaps were elevated from the cranial bone and each layer was detached separately. Contrast enhancement of the full thickness of the scalp, macroscopic evaluation, and histologic analyses were performed. Radiographs were obtained and image analysis was performed using a 3-dimensional monitor. Results: The mean number of deep vessels extending from the parietal branch of the superficial temporal artery was 68.7, including 14.2 and 54.5 vessels on the proximal and distal sides, respectively. The mean number of deep vessels extending from the frontal branch of the superficial temporal artery was 71.6, including 17.6 and 54.0 vessels on the proximal and distal sides, respectively. There were significantly more perforating branches in the distal area than in the proximal area of both the frontal and parietal branches (P = 0.005). There was no significant difference in the number of perforating branches between the frontal and parietal branches. Conclusions: Contrast-enhanced images of the loose areolar tissue and periosteal layers revealed vessels that extended radially. We successfully identified the 3-dimensional structure of the perforating vessels peripheral to the temporal fossa. Our findings provide a theoretical foundation for the feasibility of elevating a periosteal/loose areolar tissue flap with a reliable blood supply without sacrificing the temporal muscle.