title: Double-blind, randomized, controlled clinical trial to compare safety and efficacy of a metallic cannula with that of a standard needle for soft tissue augmentation of the nasolabial folds.
abstract: BACKGROUND
  Injection-related side effects and complications are likely to occur during or after filler injections; they are mainly caused by the injection technique.
  
  
  OBJECTIVE
  To assess safety and efficacy of a metallic cannula to inject hyaluronic acid (HA) filler in the nasolabial folds and to compare the safety of this cannula with that of a standard needle.
  
  
  METHODS
  This was a prospective, randomized, phase II, double-blinded study that included 25 participants with Grade 2 to 3 for bilateral nasolabial folds according to the Modified Fitzpatrick Wrinkle Scale (MFWS). The side of the injection was randomized (cannula or needle), and 0.5 mL of HA was injected into each nasolabial fold.
  
  
  RESULTS
  At day 3, mean MFWS score fell from 2.40 ± 0.40 to 1.46 ± 0.52 (p < .001) on the cannula-injected side and from 2.40 ± 0.40 to 1.48 ± 0.60 (p < .001) on the regular needle-injected side. Participants reported fewer side effects on the side injected with the new tool on the day of the injections: pain (p = .03), edema (p < .001), redness (p = .01) and hematoma (p < .001) than on the needle side.
  
  
  CONCLUSIONS
  The new cannula is a safe and useful tool to inject HA fillers in the nasolabial folds, producing less pain, edema, hematoma, and redness than regular needles.
authors.affiliation: Brazilian Center for Studies in Dermatology, Porto Alegre, Brazil. doris@hexsel.com.br
authors.forename: Doris
authors.initials: D
authors.lastname: Hexsel
authors.forename: Mariana
authors.initials: M
authors.lastname: Soirefmann
authors.forename: Manoela Donida
authors.initials: MD
authors.lastname: Porto
authors.forename: Carolina
authors.initials: C
authors.lastname: Siega
authors.forename: Juliana
authors.initials: J
authors.lastname: Schilling-Souza
authors.forename: Cristiano
authors.initials: C
authors.lastname: Brum
mesh_terms: D000328:Adult; D057785:Catheters / Q000009:adverse effects; D003357:Cosmetic Techniques / Q000009:adverse effects / Q000295:instrumentation*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006820:Hyaluronic Acid / Q000008:administration & dosage*; D007271:Injections, Intradermal; D008875:Middle Aged; D060052:Nasolabial Fold; D009339:Needles / Q000009:adverse effects; D015595:Skin Aging
chemical_list: D006820:Hyaluronic Acid