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

BACKGROUND: The longevity of polydioxanone (PDO)-barbed lifting threads remains controversial. OBJECTIVES: The authors sought 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, the authors suggested a paradigm shift to incorporate biochemical factors in enforcing the physico-mechanical lift. A nude mouse model was employed to evaluate their theory 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 employing 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 threefold greater than those around the barb-free areas of the threads. In the crisscross implantation pattern, width and density of the fibrotic areas were fivefold 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 a 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 thread, and, therefore, extend the longevity of the result.