Risk Comparison of Filler Embolism Between Polymethyl Methacrylate (PMMA) and Hyaluronic Acid (HA)

BACKGROUND: The incidence of vascular complications varies among different fillers. The main purpose of this study was to compare the risk of embolism between PMMA (Artecoll) and hyaluronic acid (HA, Restylane) after artery injection. METHODS: Rabbit ears were injected via the central artery with 0.1 ml PMMA (group A), 0.1 ml HA (group B), 0.2 ml PMMA (group C), or 0.2 mL HA (group D), respectively. The formation of transparent emboli was monitored right after injection. Tissue necrosis and histopathological changes were analyzed on day 7. RESULTS: With 0.1 ml injected volume, PMMA was dispersed within a few minutes and only 5% of the injected ears had mild necrosis on day 7, while HA tended to form obvious transparent emboli, an indication of blood vessel clotting, and 60% of injected ears showed necrosis on day 7. With 0.2 ml injected volume, PMMA had a risk of complete blood vessel clotting in between 0.1 ml PMMA group and 0.1 ml HA group, and 30% of injected ears had necrosis; in contrast, 100% of 0.2 ml HA-injected ears showed transparent emboli and necrosis. The necrosis areas were significantly increased in the HA groups compared with PMMA groups at the same injection volumes. HA injection also caused dilation of small blood vessels. CONCLUSION: At the same injection volume, PMMA had less risk of embolism compared with HA. With increased injection volume, there were increased risks of embolism and necrosis for both PMMA and HA. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s00266-019-01320-w) contains supplementary material, which is available to authorized users.