Vascular Anatomy of the Temporoparietal Fascia in Microtia: A Computed Tomographic Angiographic Analysis of 172 Patients.

Abstract

Temporoparietal fascia (TPF) flaps are widely used in auricular reconstruction; however, their vascular anatomy remains poorly defined in patients with microtia. This study aimed to characterize the arterial and venous anatomies of the TPF to improve the safety and reliability of flap elevation. Preoperative computed tomography angiography (CTA) images of 172 patients with microtia (2011-2024) were retrospectively analyzed. Arterial and venous origins, branching patterns, and artery-vein (A-V) distances were evaluated. Associations between hemifacial microsomia (HFM) and the severity of mandibular hypoplasia were also assessed. The most common vascular pattern was the superficial temporal artery (STA) and vein (STV) combination (60.3%), followed by the postauricular artery (PAA) and vein (PAV) combination (17.9%). PAA-PAV involvement was more frequent in HFM and increased with mandibular dysplasia severity. In all PAA cases, the artery followed an anteriorly displaced course. The STV often ran independently, typically as a single parietal branch, while the STA usually exhibited two branches. A-V distances between the STA and STV increased distally (p < 0.001). PAV-based flaps required significantly greater width due to their posterior course. Significant anatomical variations exist in the vascular supply of the TPF in microtia, particularly in HFM. The STV frequently acts as an independent vein rather than accompanying the STA. Understanding these patterns and using preoperative vascular imaging is essential for safe flap elevation and improved reconstructive outcomes.