Efficacy and safety of polyacrylamide hydrogel for facial soft-tissue augmentation in a 2-year follow-up: a prospective multicenter study for evaluation of safety and aesthetic results in 101 patients.

Background: Polyacrylamide (Aquamid) is a nonabsorbable soft-tissue filler. It consists of a polyacrylamide hydrogel. Safety and aesthetic results after injection of polyacrylamide hydrogel for facial soft-tissue enhancement were analyzed in a clinical trial.

Methods: In a prospective multicenter study, 251 patients were enrolled for injection of polyacrylamide hydrogel (Aquamid). The results of the first year follow-up have been described previously. One hundred one of 251 initially enrolled patients could be recruited for follow-up 24 months after the first injection. Standardized photographs were taken, and blood and urine samples were collected before treatment and during follow-up visits. Common sites of injection were nasolabial folds, lips, glabella folds, and other sites. The amount of injected gel ranged from 0.2 to 12 ml.

Results: A course of 24 months was followed in 101 patients. Results were judged to be good or very good by the investigators in 93 patients. Eighty-six patients judged the aesthetic outcome as satisfactory or very satisfactory. No severe side effects were observed during the 2-year follow-up period. Transient local reactions that resolved spontaneously were detected in several patients. In one case, burning sensations after lip augmentation were reported lasting up to the 24-month follow-up visit.

Conclusions: Polyacrylamide hydrogel (Aquamid) yielded satisfying aesthetic results in more than 90 percent of patients. There was no difference in efficacy between 12 and 24 months' follow-up. No adverse soft-tissue reaction was observed. The study group may be biased, as patients with bad results may have refrained from further follow-up. Long-term follow-up is necessary.