Collagen stimulation synergy of a hybrid protocol: combining high-intensity focused ultrasound (HIFU) and poly-L-lactic acid (PLLA) in facial rejuvenation

Background. The trend of modern aesthetic medicine is the integration of hybrid protocols for comprehensive treatment of involutional skin changes. Existing studies demonstrate the potential synergistic effect of combining high-intensity focused ultrasound (HIFU) and poly-L-lactic acid (PLLA), but there is a lack of data on morphofunctional and structural changes associated with combined application of the methods in facial skin rejuvenation. Objective. To compare the efficacy and safety of separate and combined simultaneous treatment of facial skin age-related changes with HIFU and PLLA. Material and methods. This prospective study included 11 female patients aged 35-72 years with different morphological aging patterns. The protocol involved sequential HIFU treatment followed by PLLA injection, as well as separate HIFU or PLLA administration in different facial areas. Outcomes were assessed using the GAIS scale, corneometry, cutometry, and ultrasound examination (US). Results. The combined approach demonstrated the highest improvement according to the Physician Global Aesthetic Improvement Scale (PGAIS): marked improvement was observed in 36.4% of patients, moderate improvement in 63.6%. Subject Global Aesthetic Improvement Scale (SGAIS) showed consistent results. The analysis of morphofunctional skin characteristics confirmed the significant efficacy of hybrid correction: skin elasticity improved by 17.8% in areas of combined treatment and by 6.8% with HIFU monotherapy; hydration of the stratum corneum improved by 29.9% with combined treatment and by 24% with HIFU monotherapy. As assessed by US, both dermal thickness and acoustic density significantly increased in both treatment modalities. Both monotherapy and complex protocols showed good tolerability, with transient local adverse events resolving spontaneously. Conclusion. The hybrid protocol combining HIFU and PLLA demonstrates high clinical efficacy and favorable safety profile in facial skin anti-aging treatment