Lumen Diameter and Associated Anatomy of the Superior Labial Artery With a Clinical Application to Dermal Filler Injection

BACKGROUND: Vascular compromise and subsequent tissue necrosis is a rare but disfiguring complication of dermal filler injection that frequently occurs in regions of the lip and nasolabial fold supplied by the superior labial artery (SLA). OBJECTIVE: The purpose of this study was to examine lumen diameter and other anatomical features of the SLA relevant to dermal filler injection in the clinical setting. MATERIALS AND METHODS: Eighteen adult cadavers were dissected. Detailed measurements of the SLA were taken at predetermined points along its course. RESULTS: Lumen diameter of the SLA was largest at the labial commissure (0.85 ± 0.34 mm; Point P1) and smallest at the midline (0.56 ± 0.21 mm; Point P4). The deepest mean cutaneous depth of the SLA was at its branch point from the facial artery (5.49 ± 1.95 mm; SLA branch point), whereas the most superficial mean cutaneous depth was at the midpoint between the labial commissure and peak of Cupid's bow (4.29 ± 1.54 mm; Point P2). CONCLUSION: The variable, superficial course of the SLA and its large caliber place it at significant risk for intra-arterial injection with dermal filler at all points along its course.