A Preliminary Study of Polycaprolactone Filler After Hyaluronidase for Facial Overfilled Syndrome

Hyaluronidase effectively degrades hyaluronic acid (HA) fillers in facial overfilled syndrome (FOS). However, the subsequent volume reduction may create soft tissue hollowing and contour irregularities.

To evaluate the aesthetic and structural changes following polycaprolactone (PCL) filler injection after hyaluronidase treatment in patients with FOS.

This single-arm, retrospective study enrolled patients with FOS who underwent hyaluronidase treatment followed by a PCL injection. Outcomes included Global Aesthetic Improvement Scale (GAIS), upper cheek fullness, temporal hollowing, 3D midfacial volume, and ultrasound-measured soft tissue-to-bone distance. Assessments were performed at baseline, after hyaluronidase, and at 3 and 6 months post-PCL treatment.

12 patients were enrolled. At 6 months after PCL injection, improvements were observed in GAIS (P < 0.001) and upper cheek fullness (P = 0.016). Using the pre-hyaluronidase state as baseline, the 3D midfacial filler volume decreased by 2.48 mL after hyaluronidase injection (P < 0.001), by 4.88 mL at 3 months after PCL treatment (P < 0.001), and by 5.14 mL at 6 months after PCL treatment (P < 0.001). Conversely, the ultrasound-assessed distance from soft tissue to bone surface was 1.21 mm greater than baseline after hyaluronidase treatment (P < 0.001), and 2.09 mm and 3.23 mm lower than baseline at 3 and 6 months after PCL injection, respectively (both P < 0.001). No adverse events were reported after hyaluronidase and PCL treatment.

In this preliminary study, aesthetic improvement and changes in soft tissue parameters were observed after PCL injection following hyaluronidase treatment.