Utility of Preinjection Aspiration for Hyaluronic Fillers: A Novel In Vivo Human Evaluation

Abstract

Background

Hyaluronic acid (HA) fillers have increased in popularity. While complications are rare, practitioners should focus on their prevention. Preinjection aspiration remains controversial as an effective safety checkpoint.

Objectives

Our study investigated the utility of preinjection aspiration as a safety checkpoint for HA fillers through comparison of physiochemical and rheological properties in a novel in vivo human model.

Methods

An in vivo human model consisted of a cannula inserted into a peripheral vein. Preinjection aspiration was evaluated using syringes of 10 commonly used HA fillers. The time required to visualize a flash was recorded.

Results

Using a multivariable regression model, needle gauge, HA concentration, elastic modulus (G′), viscous modulus (G″), and complex modulus (G*) had significant relationships with time to flash, whereas pullback volume did not. However, when comparing pullback volume using a more appropriate paired analysis, 0.5 cc pullback volume had a significantly decreased time to flash than 0.2 cc.

Conclusions

Preinjection aspiration for HA fillers has utility as a safety checkpoint. The times to visualize flashback decreased when using a human peripheral vein model compared to a previous in vitro model, suggesting that there may be real-time clinical utility of preinjection aspiration. Waiting times to visualize flashback may be affected by physiochemical and rheological properties. Additional studies would help to validate our results.