Tissue changes over time after polydioxanone thread insertion: An animal study with pigs

Abstract

Background Polydioxanone (PDO) sutures have been widely used to tighten and lift the face. However, why the complexion brightens and skin elasticity is maintained with a smaller facial outline after a PDO monofilament thread treatment remains unclear. Aims We aimed to determine what significant changes occur in the tissue over time when a PDO suture is inserted. Methods We selected four White Yucatan variety pygmy pigs with skin that most closely resembles the structure of human skin. 4-0 PDO thread was inserted into the subcutaneous fat. Tissue samples were obtained at 4, 12, 24, and 48 weeks. For the histologic analysis, H&E staining, Masson trichrome staining, and anti-smooth muscle actin immunohistochemical staining techniques were used. Results Nine histological findings appeared over time, and these findings are summarized as five tissue changes. Conclusions PDO sutures cause specific changes to the surrounding tissues that result in neo-collagenesis, a fibrous merging effect, fat reduction, tissue contracture, and an improved vascular environment. The results of this study explain the positive changes described in previous clinical research.