Italian Expert Consensus on Poly(ethylene glycol) Diglycidyl Ether-Crosslinked Hyaluronic Acid Hydrogels for Facial Aesthetics: Product Selection, Injection Techniques, and Safety

Background: Hyaluronic acid (HA) hydrogels are the most widely used injectable fillers for facial rejuvenation. A new generation of HA fillers crosslinked with poly(ethylene glycol) diglycidyl ether (PEGDE) has been developed to enhance cohesiveness, tissue integration, stability, and longevity while minimizing swelling and immunogenicity. Owing to their distinct viscoelastic properties, PEGDE-crosslinked HA fillers may require product-specific selection and adapted injection techniques. Objective: The objective of this study is to provide practical, expert-based recommendations for the safe and effective use of PEGDE-crosslinked HA hydrogels in facial aesthetic treatments. Methods: A multidisciplinary panel of nine Italian experts in aesthetic medicine, each with more than 15 years of experience using HA fillers, developed consensus recommendations based on clinical practice and available evidence. A pre-meeting questionnaire informed structured discussions during a face-to-face meeting held in Paris in January 2024. The nominal group technique was applied, with consensus defined as agreement by at least 80% of panel members. Results: Consensus was reached on product selection, injection planes, delivery devices, techniques, and typical treatment volumes for PEGDE-HA hydrogels across multiple facial regions, including the forehead, temples, midface, nasolabial folds, chin, jawline, and lips. Recommended injection techniques included microbolus, macrobolus, and retrograde linear threading, with placement ranging from superficial subcutaneous to supraperiosteal planes depending on the anatomical area and clinical indication. Typical injection volumes generally ranged from 0.1 to 0.5 mL per side. Optional ultrasound mapping was considered beneficial in selected high-risk or superficial procedures to improve anatomical safety. Conclusions: These expert consensus recommendations provide practical guidance for clinicians using PEGDE-crosslinked HA hydrogels in facial rejuvenation. Tailoring product characteristics to injection depth, technique, and regional anatomy may help optimize clinical outcomes and procedural safety. Future research priorities include prospective comparative studies with other crosslinking technologies, standardized reporting of adverse events, long-term outcome registries, and further evaluation of ultrasound-guided injection strategies.