Commentary on: New High Dose Pulsed Hyaluronidase Protocol for Hyaluronic Acid Filler Vascular Adverse Events

Soft tissue augmentation of the face has grown in popularity and demand in the past decade. Since the Food and Drug Administration approval of Restylane (Medicis, Scottsdale, AZ) in December, 2003, the number of approved hyaluronic acid fillers in the United States has increased, as has the public interest for these products. As the incidence of injectable facial fillers has increased, so has the number of complications associated with vascular compromise from these injections. The need for early intervention with a treatment algorithm including hyaluronidase has been well established. The article “New High Dose Pulsed Hyaluronidase Protocol for Hyaluronic Acid Filler Vascular Adverse Events” suggests a change in the treatment of patients with known or suspected vascular compromise after facial filler injection.1 Prior treatment protocols have included hyaluronidase, aspirin, topical nitroglycerin, warm compresses, and hyperbaric oxygen. The dosage and interval of hyaluronidase has been mostly anecdotal, and practitioners have usually injected this into the affected (compromised) area with usual follow up and reinjection in 24 to 48 hours. Because of the reported incidence of tissue necrosis and subsequent skin and soft tissue scarring, and the possible occurrence of blindness in the periorbital region, practitioners have increased their recognition and treatment of these problems. This paper by DeLorenzi introduces a new treatment protocol for patients with vascular compromise secondary to occlusion from embolic events after facial filler injection. The paper suggests that only hyauronidase is necessary to treat the occluded vessel(s), and that the treatment is best performed with an increased frequency than what has been suggested previously and by many clinicians. DeLorenzi terms the treatment high dose pulsed hyaluronidase. He recommends the repeated administration of high doses of injected hyaluronidase into the affected tissue hourly until resolution of symptoms and signs of ischemia. This includes that the tissue is no longer painful, regains normal color, and exhibits good capillary refill on physical examination. The protocol also proposes that other treatment modalities, such as aspirin, warm compresses, and topical notrogycerin paste, are unnecessary and do not improve therapeutic outcomes. DeLorenzi postulates that there are several reasons to suggest the need for more frequent hyaluronidase inject into patients with vascular compromise. These include the fact that after injection, the ischemic area produces a transudate that causes dilution and inactivity of hyaluronidase. Additionally, hyaluronidase begins to be degraded and diffuses away from the original injection site. DeLorenzi theorizes that these factors combine to reduce the action of the injected enzyme, thus necessitating repeat injection to produce the desired effect. He also notes that the same crosslinking that prevents the body from breaking down the product also serves to prevent more rapid degradation of the product when hyaluronidase is injected to treat a vascular obstruction.