Effect of Injection Techniques on the Rate of Local Adverse Events in Patients Implanted with Nonanimal Hyaluronic Acid Gel Dermal Fillers

Abstract

BACKGROUND One question associated with dermal fillers is whether the rate and variability of local adverse events following treatment are related to injection technique and needle trauma or to the intrinsic chemical composition. OBJECTIVE The objective was to determine if there is a relationship between dermal filler injection technique and the incidence of local adverse events. METHODS AND MATERIALS A prospective, blinded, controlled study enrolled 283 patients who were randomized to receive midface volume correction of the nasolabial folds and oral commissures with the nonanimal-stabilized hyaluronic acid (NASHA) gel filler Restylane or Perlane (Medicis Pharmaceutical Corp.). Data were collected on multiple injection technique variables to assess adverse events. RESULTS Injection techniques that increase the dissection of the subepidermal plane (e.g., fanlike needle use, rapid injection, rapid flow rates, and higher volumes) increased the incidence of local adverse events. Injection techniques that increase epidermal damage or subcutaneous exposure (e.g., multiple punctures or deep subcutaneous injection) had no effect on adverse events. Furthermore, single injection correction, depth of injection, and NASHA product injected had no effect on local adverse events. CONCLUSIONS Local adverse events following injection with the NASHA gel fillers used in this study were related to investigator technique and not to differences in the intrinsic properties of the NASHA agents.