Intralesional hyaluronidase injection to relieve non-hyaluronic acid filler-induced vascular adverse events.

[BACKGROUND] Vascular adverse events (VAEs) occurring during injections of soft-tissue fillers are still considered a challenging issue for both patients and practitioners. Hyaluronidase can dissolve hyaluronic acid (HA)-based soft-tissue fillers during a VAE. For VAEs induced by non-HA fillers, the absence of an "antidote" is regarded as exceptionally challenging.

[METHODS] This multicenter study describes a case series of three VAEs induced by non-HA fillers, for which ultrasound-guided hyaluronidase injections were incorporated into the treatment approach.

[RESULTS] Two cases of calcium hydroxylapatite and one case of poly-L-lactic acid-induced VAEs are described, all of which were resolved without necrosis or scarring using a treatment approach with ultrasound-guided hyaluronidase injections.

[CONCLUSIONS] Unlike the mechanical hypothesis, which assumes filler particles travel antegrade to block arterioles in a large skin area, we hypothesize vasoconstriction as the pivot in VAEs. Filler injection-induced spasms could lead to long-lasting vasoconstriction of the perforator arteries stemming from the central facial arteries. Our results underscore that perforasome vasoconstriction might be the leading cause of the ischemia and subsequent necrosis in VAEs and that relaxation of these perforasomes, rather than dissolving the filler material, resolves the clinical symptoms associated with VAEs.