Transarterial degradation of hyaluronic acid filler by hyaluronidase.

[BACKGROUND] Hyaluronidase (HYAL) has been recommended in the emergency treatment of ischemia caused by accidental intra-arterial injection of hyaluronic acid (HA) dermal fillers. To date, there have been no published studies showing that HYAL can pass through intact arterial wall to hydrolyze HA emboli.

[OBJECTIVE] The goal of this study was to study whether or not HYAL could cross intact human facial arterial wall to hydrolyze HA filler.

[MATERIALS AND METHODS] Short tied-off segments of fresh human cadaver-sourced facial artery specimens, overfilled with a monophasic dermal filler (dermal filler "sausages"), were immersed in either HYAL or normal saline as controls. At 4 and 24 hours, the vessels were removed from the preparations, and one end of each vessel was cut open.

[RESULTS] Only the HYAL-immersed specimens showed degradation of filler gel.

[CONCLUSION] In conclusion, cross-linked HA is susceptible to hydrolysis by HYAL when contained within the intact facial artery in a cadaver model, indicating that direct intra-arterial injection of HYAL is likely not necessary to help restore the circulation of ischemic tissues. This bench study provides support for the current recommended treatment of accidental intra-arterial injection with HYAL injection diffusely into ischemic tissues.