Complications of collagen biostimulators in Brazil: Description of products, treatments, and evolution of 55 cases

Background: Complications of temporary and permanent fillers have been extensively studied. However, there is a lack of comparative data regarding poly-L-lactic acid (PLLA), calcium hydroxyapatite (CaHA), and polycaprolactone (PCL) known as collagen biostimulators. Aims: This study addressed the complications of collagen biostimulators concerning their diagnosis, type of product, treatment, and monitoring. Patients/Methods: An electronic questionnaire was sent to Brazilian dermatologic ultrasound experts to identify complications related to biostimulators. The type of biostimulator, location of application, number of vials injected, application plan, time between injection treatment and complication, injector profile, treatment, and prognosis were assessed. Results: Fifty-five cases were identified, of which 49.1% were caused by PLLA-Elleva®, 23.6% by CaHA (alone or combined with hyaluronic acid), 20.0% by PLLA-Sculptra®, and 7.3% by PCL. The most affected area was the face (72.7%), with nodules being the most common clinical form (89.1%), generally occurring late (60.0%) (>1 month). Only one case was injected at an incorrect depth (musculoaponeurotic system—SMAS). Despite several treatments, including saline (45.5%), hyaluronidase (25.5%), diluted corticosteroids (23.6%), and energy-based devices (10.9%), only five cases showed complete resolution. Hyaluronidase was beneficial in complications related to fillers when there was an association of calcium hydroxyapatite with hyaluronic acid (p < 0.01). Conclusions: Complications from collagen biostimulators were more common on the face, typically manifesting about 1 month after treatment. These issues seemed to be related more to the properties of the products rather than inadequate technique. Furthermore, hyaluronidase demonstrated efficacy only in cases where there was an association with HA.