Tissue reactions to cog structure and pure gold in lifting threads: a histological study in rats

Aesthet Surg J. 2011 Mar;31(3):347-51. doi: 10.1177/1090820X11398474.


Background: Thread lifting has become popular as a minimally-invasive suspension procedure, but there is little basic and clinical evidence in the literature on the long-term effects.

Objectives: The authors investigate the effects of two types of lifting threads in a rat model over the course of seven months.

Methods: The dorsal skin of 18 Wistar rats was implanted with a 20-mm fragment of one of three types of thread: nonabsorbable monofilament cog, pure gold (24 karat) with no cog, and pure gold-coated cog. Six rats were in each group. Tissue samples were harvested and histologically evaluated at one, three, and seven months.

Results: Histological assessment indicated (1) acute tissue reactions to the regular cog thread involving myofibroblasts and (2) delayed tissue reactions to the pure gold thread involving giant cells. The gold-coated cog thread showed a combination of the histological reactions associated with the cog thread and the pure gold thread, including faint early reactions, strong delayed reactions, and long-lasting capsule formation. Notably, the gold coating gradually came loose from the thread surface, suggesting that the release of tiny gold particles may promote longer-lasting tissue reactions.

Conclusions: The combination of cog structure and pure gold coating was evaluated for the first time in this study and results suggest that the gold-coated cog thread has clinical potential.

MeSH terms

  • Animals
  • Foreign-Body Reaction / etiology*
  • Giant Cells / metabolism
  • Gold* / adverse effects
  • Minimally Invasive Surgical Procedures / adverse effects
  • Minimally Invasive Surgical Procedures / methods*
  • Myofibroblasts / metabolism
  • Rats
  • Rats, Wistar
  • Skin / metabolism
  • Suture Techniques / adverse effects
  • Sutures* / adverse effects
  • Time Factors


  • Gold