In Vivo Ultrasound Study of the Angular Artery Anatomy: Practical Indications for the Treatment of the Deep Pyriform Space.

Background: The increase in adverse events parallels the increase in aesthetic procedures. Injecting fillers at bone level in the pyriform space has been considered safe, as the angular artery (AA) has been described as crossing this space in a plane closer to the skin than to the bone. However, severe adverse events can occur with this injection modality, even in the pyriform space. Objectives: Our study aimed to assess the course and depth of AA in the pyriform space using Doppler ultrasound (US). Methods: The pyriform space was investigated by a US device provided with a 20 MHz probe in healthy volunteers. They were studied in a semi-seated position with the probe positioned vertically with its central pointer at the angle between the lateral nose nostril and the cheek skin. The distances between the AA-skin and AA-bone planes were measured in millimeters. Results: The AA distance from the bone was <1 mm in 3% of cases and >3 mm in 57% of cases. The AA runs outside the pyriform space in 5% of cases. Conclusions: The course of AA in pyriform space is highly variable, and sometimes, it can be close to the bone. A US examination of the AA in the pyriform space can identify the AA course, aiding in avoiding complications such as injecting or compressing the AA. Level of Evidence 4 Diagnostic: