Evaluation of supratrochlear artery depth and course variations by Doppler ultrasonography along the glabellar frown lines for safer filler injections.

Purpose: Hyaluronic acid (HA) injection is a popular nonsurgical, rejuvenating procedure to treat glabellar frown lines, which has devastating complications such as blindness and skin necrosis due to the arterial occlusion of supratrochlear artery (STA). Therefore, when injecting into the frown lines, knowledge of the STA's depth and plane is necessary to prevent possible adverse events. The aim of this study was to identify the depths of STA in the area of the frown lines in order to maximize safety during filler injections.

Methods: Supratrochlear artery depth measurements were performed at the level of eyebrow and at the level of 1.5 cm above the eyebrow. Superficial duplex Doppler ultrasonography was performed of 71 cases.

Results: In the eyebrow level, the epidermis-artery distance (EAD) is between 1,8 and 5.9 mm, and the artery-periost distance (APD) is between 0.7 and 3.7 mm. In the 1.5 cm superior level of the eyebrow, the EAD is between 1.8 and 5.1 mm and the APD is between 0.6 and 3.8 mm. There was no significant difference between the depth measurements of the right and left STA. At the eyebrow level, APD is greater in men than in women. As the body mass index increases, the EAD and APD depth increases. EAD depth increases with increasing age.

Conclusions: Based on the findings of this study, safe filler injections to correct the glabellar frown lines can be possible with intradermal injections just below the ryhtide. In the glabellar region, subcutaneous and supraperiosteal injections seems to be risky.