Direct Microscopic Visualization of Perforators Within the Subcutaneous Pedicle in Microtia Reconstruction

In microtia reconstruction, preservation of a subcutaneous pedicle is essential for maintaining perfusion of the posterior skin flap to cover the costal cartilage framework. Although this pedicle contains multiple perforators, their detailed courses remain poorly understood. This lack of anatomic information has limited the extent to which the subcutaneous pedicle can be safely thinned or refined. This study aimed to characterize the vascular course and distribution of perforators within the subcutaneous pedicle through direct intraoperative microscopic observation. This single-center study included 4 patients with congenital unilateral microtia who underwent first-stage auricular reconstruction with autologous costal cartilage between July and December 2023. Microsurgical techniques were used to identify and preserve perforators within the subcutaneous pedicle. Intraoperative indocyanine green angiography (ICGA) confirmed perfusion through these perforators. Postoperative contrast-enhanced CT findings were consistent with the intraoperative observations. Microscopic observation revealed that perforators entered the pedicle from both its anterior and posterior aspects of the auricle. Intraoperative ICGA demonstrated both arterial inflow and venous outflow through the preserved perforators. Although posterior vessels were intentionally divided to facilitate cartilage placement, no partial or total flap necrosis was observed. Direct intraoperative microscopic observation identified anterior perforators in the subcutaneous pedicle entering the dermal vascular plexus. These findings are consistent with a perforator-based concept that may facilitate thinning and refinement of the subcutaneous pedicle.