Complications from Nasolabial Fold Injection of Calcium Hydroxylapatite for Facial Soft-Tissue Augmentation: A Systematic Review and Meta-Analysis

Despite its increasing usage of facial applications, there is a paucity of objective data regarding calcium hydroxylapatite (CaHA). To systematically evaluate the complications from CaHA injection for facial soft tissue augmentation. Published studies on CaHA injection for facial soft tissue enhancement were identified through searches of the PubMed, EMBASE, and Cochrane Controlled Trial databases. Only randomized, controlled trials comparing CaHA injection to either placebo or an active comparator for facial cosmetic use were included. The outcome measures were the count (n) and frequency (%) of each complication, including edema (swelling), erythema (redness), ecchymosis (bruising), pain, pruritus (itching), hematomas, nodules, and extrusions. Four studies on nasolabial fold (NLF) injection of CaHA consisting of two subgroups were included: (i) a CaHA-lidocaine vs CaHA subgroup and (ii) a CaHA vs hyaluronic acid (HA) subgroup. The addition of lidocaine to CaHA therapy displayed no significant effect on edema (RR (95% CI): 1.07 (0.94-1.21), P = .311), erythema (RR (95% CI): 0.91 (0.66-1.24), P = .544), ecchymosis (RR (95% CI): 1.04 (0.71-1.52), P = .843), pain (RR (95% CI): 0.88 (0.58-1.33), P = .553), or pruritus (RR (95% CI): 0.82 (0.45-1.50), P = .515). There was no significant difference between CaHA vs HA for hematomas (RR (95% CI): 0.24 (0.01-4.31), P = .332) or nodules (RR (95% CI): 0.18 (0.01-6.62), P = .353). There was no significant publication bias detected in either subgroup (Begg's test P > 0.05). These findings support the addition of lidocaine to NLF injection of CaHA and suggest an equivalence between CaHA and HA with respect to hematoma and nodule formation. Risk