Transvascular hydrolysis of hyaluronic acid filler with hyaluronidase: An Ex vivo study

BACKGROUND Despite the favorable safety profile of hyaluronic acid (HA) dermal fillers, side effects can occur. Skin necrosis is one of the most severe early-occurring complications resulting from accidental vascular impairment. Hyaluronidase (HYAL) is commonly used to degrade HA chains, allowing the degraded product to pass through vessels, and thus relieving the vascular obstruction. OBJECTIVE The purpose of this study is to evaluate, in an ex vivo setting, the capability of HYAL to degrade crosslinked HA that was injected into human vessels. MATERIALS AND METHODS During a neck dissection, a portion of the anterior jugular vein and facial artery was harvested. The vein and artery specimens were filled with 25 mg/mL of crosslinked HA filler. Each specimen was soaked in 0.5 mL of HYAL (300 IU/mL), in its own test tube, for 4 hours, after which the remaining HA was quantified. RESULTS The remaining HA volume was found to be 0.02 mL in the vein segment and 0.002 mL in the artery segment. CONCLUSION A single administration of HYAL may not be adequate to restore blood flow in the event of embolism, and relatively high doses of this enzyme must be injected hourly into the affected tissue until resolution is complete.