Favorable Crisscrossing Pattern With Polydioxanone: Barbed Thread Lifting in Constructing Fibrous Architecture.

BACKGROUND The longevity of polydioxanone (PDO)-barbed lifting threads remains controversial. OBJECTIVES To assess the longevity extension effect of a crisscross implantation pattern in PDO-barbed thread lifting. METHODS To acquire the desired outcome in PDO-barbed thread lifting, we suggested a paradigm shift to incorporate biochemical factors in enforcing the physico-mechanical lift. A nude mouse model was used to evaluate our theory, i.e., to compare the conventional fan-shaped protocols in barbed thread lifting with an architectural construction of intersections of fibrous capsule in a crisscross pattern. Three fragments of monofilament PDO-barbed lifting threads were implanted in the dorsal skin of 12 nude mice. The pattern of implantation was fan-shaped in the control group and crisscross in the experimental group. Tissue specimens containing tangential areas of threads were harvested, fixed, and paraffin-embedded. Samples were horizontally cut and histologically analyzed using hematoxylin and eosin, Massons' Trichrome, and Sirius red staining. Fibrotic areas and the width of fibrosis from the thread were also analyzed. RESULTS Fibrous capsulations around the barbed area of the PDO-barbed lifting threads were three-fold greater than those around the barb-free areas of the threads. In the crisscross implantation pattern, width and density of the fibrotic areas were five-fold greater than those of the fan-shaped areas. Induction of fibrous capsules around the PDO-barbed thread was markedly condensed in the crisscross areas. CONCLUSIONS This study provides the basis for more logical implantation pattern in PDO-barbed lifting threads for facial rejuvenation. By generating controlled multiple crisscross patterns, we can create more intense fibrogenesis, reduce tension applied on each barbed threads and as a result, extend the longevity of the result.