Safety of the Immediate Reconstitution of Poly-<sc>l</sc>-Lactic Acid for Facial and Body Treatment-A Multicenter Retrospective Study

Background: Poly- l- lactic acid (PLLA- SCA; Sculptra) was approved in 1999 in Europe and 2004 in United States as a collagen biostimulator. It is a freeze- dried preparation containing 150 mg PLLA- SCA per vial and, since approval, has been recommended to be reconstituted 72 h before treatment, which can hinder its use in clinical practice. In 2021, the manufacturer authorized the reconstitution of PLLA- SCA immediately before use. Objective: To evaluate adverse events in patients treated with immediately reconstituted PLLA- SCA on the face, body, and scars. Method: This was a retrospective analysis of medical records of patients treated with immediately reconstituted PLLA- SCA for aesthetic purposes from January 1, 2021, to December 31, 2021, at two medical centers. Results: A total of 274 treatment sessions were conducted on 167 patients (ranging from 1 to 5 sessions per patient). Of these, 228 sessions (151 patients) targeted the face, 39 sessions (22 patients) addressed the body, and 7 sessions (5 patients) focused on scars. The mean final concentration of PLLA- SCA was 15.30 mg/mL for the face, 8.35 mg/mL for the body, and 10.53 mg/mL for scars. The majority of injections were administered with a blunt cannula (face: 87.3%, body: 100%, scars: 57%), and in 6 out of 7 scar treatments, PLLA- SCA was additionally applied topically after fractional treatment. One patient developed a PLLA- SCA nodule 30 days after facial treatment, which resolved after two saline injections. The most common adverse events were bruising (face: 6.57%, body: 7.69%) and mild pain (face: 3.07%). No events required further intervention. Conclusion: This study reports an adverse event profile with immediately reconstituted PLLA- SCA, used on the face, body, and scars, similar to that reported with PLLA- SCA reconstituted 72 h prior to use.