INTRODUCTION
Soft tissue augmentation is an increasingly popular aesthetic medical procedure. Hyaluronic acid (HA) fillers are commonly utilized for soft tissue augmentation.1 An advantage of HA fillers includes easy reversibility with enzymatic hyaluronidase administration.2 In clinical practice, HA degradation is utilized to manage adverse effects from HA filler including intra-vascular filler placement. Current guidelines for HA filler reversal recommend flooding the treatment area indiscreetly with hyaluronidase.3 Yet, there are no clear guidelines regarding the amount of hyaluronidase that should be administered, frequency of administration, or other dose adjustments based on filler type.4 Commercially available HA fillers differ in constituent properties such as crosslinking technology, concentration, and G' prime.5 Given this variability, it is reasonable to conclude that the HA fillers may have discordant responses to hyaluronidase-induced hydrolysis. This in vitro study demonstrates the dynamic response of 6 different commercially available HA fillers to hyaluronidase using gross and microscopic photography.
MATERIALS AND METHODS
Restylane (manufactured by Q-Med and marketed by Medicis, Inc.) and Juvederm (manufactured by Lea Derm and marketed by Allergan, Inc.) received FDA approval in 2003 and 2006, respectively.6 HA fillers used were Restylane Lyft (Lot# 20482, expiration date 02/28/2025), Restylane Defyne (Lot# 19915, expiration date 10/31/2023), Restylane Refyne (Lot# 20418, expiration date 02/28/2024), Juvederm Voluma XC (Lot# 1000552552, expiration date 03/30/2024 with 0.3% w/lidocaine in physiologic buffer), Juvederm Ultra XC (Lot# 1000533484, expiration date 12/04/2023 with 0.3% w lidocaine in physiologic buffer), and Juvederm Volbella (Lot# V15LB10889, expiration date 10/13/2023).
For the HA fillers, 0.1 mL aliquots were placed on separate slides. Then 0.1 mL of Hylenex (human recombinant hyaluronidase, 150 USP units/mL, NDC 18657-117-02) was mixed into each filler sequentially at 3 different time points approximately 2 minutes apart. Filler dilution photography was obtained with the addition of various doses of hyaluronidase (total 0 mL, 0.1 mL, 0.2 mL, and 0.3 mL).
For the HA fillers, 0.1 mL aliquots were placed on separate slides. Then 0.1 mL of Hylenex (human recombinant hyaluronidase, 150 USP units/mL, NDC 18657-117-02) was mixed into each filler sequentially at 3 different time points approximately 2 minutes apart. Filler dilution photography was obtained with the addition of various doses of hyaluronidase (total 0 mL, 0.1 mL, 0.2 mL, and 0.3 mL).
