Safety and effectiveness of injection of calcium hydroxylapatite via blunt cannula compared to injection by needle for correction of nasolabial folds

BACKGROUND: Pain and potential adverse events (AE) remain challenges for patients being treated with calcium hydroxylapatite (CaHA; Radiesse), especially CaHA not mixed with an anesthetic. The blunt cannula may provide more comfortable and lower risk delivery of CaHA for nasolabial folds (NLF) correction. OBJECTIVE: This 30-day pilot study was designed to compare the effectiveness and safety of standard needles with that of blunt cannulas for CaHA application. METHODS: Twenty patients with moderate to severe NLF received split-face injections of CaHA mixed with 2% lidocaine using a cannula for one NLF and needle for the other NLF. At day 0, patients evaluated pain; the treating investigator evaluated changes in NLF depth. At 0, 3, 7, 14, and 30 days, the investigator evaluated AEs and NLF correction. Patients recorded AEs in daily dairies. RESULTS: After initial treatment, patients experienced greater pain and displayed increased erythema and swelling in the needle-treated side. At days 3 and 7, patients displayed greater instances of bruising, redness, and swelling in the needle-treated sides. At day 30, 19 patients showed slightly better correction in the cannula-treated sides. CONCLUSIONS: The blunt cannula provided advantages in mitigation of pain and AEs, with a degree of correction similar to needle. The addition of blunt cannulas to the clinical setting may be appropriate.