Effects of monopolar radiofrequency treatment over soft‐tissue fillers in an animal model: Part 1

Abstract Background and Objectives Monopolar radiofrequency (RF) treatment is used by physicians to tighten and contour the skin of their patients. In many cases, patients have received prior treatment with other aesthetic modalities such as soft‐tissue augmentation or they may wish to receive these treatment modalities simultaneously. Together, soft‐tissue augmentation and monopolar RF treatment have the potential to restore tissue volume and improve facial laxity. To date, no published studies have documented the effects of RF treatment directly over soft‐tissue fillers. Study Design/Materials and Methods We examined the tissue interactions of monopolar RF heating with five commonly injected fillers in a juvenile pig model. This is the first part of a two‐part study. In this study, the interaction of monopolar RF and filler substances was examined over a period of 4 months. The five soft‐tissue fillers examined were cross‐linked human collagen (Cosmoplast™), hyaluronic acid (Restylane ® ), calcium hydroxylapatite (Radiesse™), polylactic acid (Sculptra™), and liquid injectable silicone (Silikon™ 1000). Results There was no apparent increase in the risk of local burns and no observable effect of RF treatment on filler persistence in the tissue. With monopolar RF treatment, an increase in fibroplasia and collagen deposition surrounding Restylane, Radiesse, and Sculptra was observed. When scored in a blinded fashion, the increase in collagen deposition was statistically significant for Radiesse. Conclusions In this animal study, RF treatment had no observed adverse effect on filler collagen responses or persistence. Filler presence did not increase the risk of undesirable thermal effects with monopolar RF treatment. Further clinical studies are required to evaluate the effect of monopolar RF treatment over dermal fillers with respect to aesthetic outcome. Lasers Surg. Med. 00:1–10,2005. © 2005 Wiley‐Liss, Inc.