Sterility of stored nonanimal, stabilized hyaluronic acid gel syringes after patient injection

Background: Restylane (Restylane; Q-Medical, Uppsala, Sweden) is a nonanimal stabilized hyaluronic acid (NASHA) that has become increasingly popular for soft tissue augmentation and volume correction because of its greater longevity and lower rate of hypersensitivity reactions when compared with collagen. Despite manufacturer warnings, the remaining material in the syringe is commonly stored for subsequent treatment in the same patient. Objective: Our purpose was to determine the incidence of bacterial contamination of NASHA stored after initial patient injection. Methods: After use of a specific sterile sequence, NASHA from previously used syringes stored at room temperature for 2 to 9 months was cultured under aerobic (n = 20) and anaerobic conditions (n = 10). Results: No bacteria were cultured from any of the samples. Limitations: Limitations of this study include sample size and storage period for a maximum of 9 months. Conclusions: NASHA remaining in syringes after patient injection was not contaminated with bacteria. Our study raises the possibility that re-use of the remaining portion of material in the syringe may be safe and is more economical than discarding it.