Safety data of injectable nonanimal stabilized hyaluronic acid gel for soft tissue augmentation

BACKGROUND. Nonanimal hyaluronic acid gel was recently developed for soft tissue augmentation and volume expansion and has been shown to offer several advantages in comparison to other augmentation materials. There are rare reports of adverse events believed to be secondary to trace amounts of proteins in the hyaluronic acid raw material. OBJECTIVE. To determine the safety profile of nonanimal stabilized hyaluronic acid gel (Restylane, Perlane, Restylane Fine Lines, Q-Med AB, Uppsala, Sweden) for soft tissue augmentation using a retrospective review of all adverse events data from Europe, Canada, Australia, South American, and Asia from 1999 and 2000. RESULTS. Data from an estimated 144,000 patients treated in 1999 indicated the major reaction to injectable hyaluronic acid was localized hypersensitivity reactions, occurring in approximately 1 of every 1400 patients treated. In 1999 there was an adverse event reported for 1 of every 650 patients (0.15%) treated. These were temporary events that included redness, swelling, localized granulomatous reactions, bacterial infection, as well as acneiform and cystic lesions. For 2000 there was an estimated 262,000 patients treated with hyaluronic acid gel. The total number of adverse events was 144, corresponding to one adverse event for every 1800 patients (0.06%) treated. The major adverse event was again hypersensitivity, occurring in 1 of every 5000 patients treated. CONCLUSION. According to the reported worldwide adverse events data, hypersensitivity to nonanimal hyaluronic acid gel is the major adverse event and is most likely secondary to impurities of bacterial fermentation. According to data from 2000, the incidence of hypersensitivity appears to be declining after the introduction of a more purified hyaluronic acid raw material.