Vascular complications of hyaluronic acid fillers and the role of hyaluronidase in management

Skin necrosis following the inadvertent arterial injection of hyaluronic acid (HA) is a serious complication. It is not clear whether or not subcutaneous injections of hyaluronidase decrease skin necrosis in HA-induced vascular complications. We had four cases of HA-induced vascular complications, two of which were treated with hyaluronidase the next day. All of the patients had skin necrosis and scarring. We performed an animal study with rabbit ears in which HA filler was injected into the auricular arteries of both ears. Five rabbits each received a subcutaneous injection of 750 IU of hyaluronidase 4 and 24 h after the filler injection. The hyaluronidase-treated ears in the 4-h intervention group had significantly smaller necrotic areas (p < 0.05), while the 24-h intervention group had no differences in the area of necrosis. Hyaluronidase reduced the vascular complications of HA fillers when used early, but there was no benefit to hyaluronidase injection after 24 h.