Comparison of Intra-arterial and Subcutaneous Testicular Hyaluronidase Injection Treatments and the Vascular Complications of Hyaluronic Acid Filler.

[BACKGROUND] Hyaluronidase is a key preventative treatment against vascular complications of hyaluronic acid (HA) filler injection, but the degradation profile of HA to hyaluronidase is limited, and the comparison between intra-arterial and subcutaneous injections of hyaluronidase has not been studied.

[OBJECTIVE] To evaluate HA degradation to hyaluronidase and compare different treatments between intra-arterial and subcutaneous testicular hyaluronidase injections.

[MATERIALS AND METHODS] The authors observed HA degradation to hyaluronidase in vitro via microscopic examination and particle analysis. Rabbit ears were used for the in vivo study. There were 2 control groups receiving ligation or HA-induced embolism in the arteries, respectively, and 2 intervention groups receiving hyaluronidase treatments in different regions. The laser Doppler blood perfusion monitoring measurements were made at defined time points, and biopsies were taken on Day 2.

[RESULTS] Nearly, all of the HAs degraded in vitro at the 1-hour time point. Subcutaneous hyaluronidase treatment showed better recovery of blood perfusion. Histology showed severe inflammation in the embolism group and mild inflammation in the intervention groups.

[CONCLUSION] A complete enzymatic degradation of HA filler to hyaluronidase needs a certain time, and subcutaneous hyaluronidase treatment may be the better option.