Models of skin graft revascularization are based mostly on histologic evaluations but lack the possibility of analyzing the vascular biology in vivo. The aim of the present study was therefore to develop an animal model that allows continuous monitoring of the microcirculation during skin graft healing.
Skin and subcutaneous tissue were removed from the back of dorsal skinfold chamber preparations in mice, leaving one layer of striated muscle and subcutaneous tissue as a wound bed (n = 5). A corresponding full-thickness skin graft was harvested from the groin and sutured into the defect in the back of the chamber. To study graft healing, repetitive intravital microscopy was performed during the first 10 days after engraftment.
Capillary widening in the wound bed appeared at day 1 after grafting and increased until day 4. Capillary buds and sprouts first appeared at day 2. Blood filling of autochthonous graft capillaries occurred at day 3, resulting in almost complete restoration of the original skin microcirculation on day 5. This was achieved by interconnections between the microvasculature of the wound bed and the skin graft through a temporary angiogenic response. In principle, angiogenic blood vessel growth originated in the wound bed and was directed toward the graft.
This new model allows for repetitive analysis of the microcirculation during skin graft healing. It provides ideal in vivo conditions to further delineate the exact mechanisms of blood vessel interconnection during the complex process of angiogenesis, and may also allow study of the vascularization of tissue-engineered skin substitutes.
Zurich, Switzerland; and Homburg-Saar and Rostock, Germany
From the Division of Plastic and Reconstructive Surgery, University Hospital Zurich; the Institute for Clinical and Experimental Surgery, University of Saarland; and the Institute for Experimental Surgery, University of Rostock.
Received for publication December 15, 2007; accepted May 28, 2008.
Presented in part at the 11th European Congress of Scientists and Plastic Surgeons, in Aachen, Germany, September 21 through 22, 2007, and awarded the Best Paper prize; and at the Chirurgische Forschungstage, in Saarbrucken, Germany, November of 2007.
Disclosure: The authors declare that they have no competing financial interests, commercial associations, or financial disclosures that might pose or create a conflict of interest with information presented in this article.
Nicole Lindenblatt, M.D.; Division of Plastic and Reconstructive Surgery; University Hospital Zurich; Rämistraße 100; 8091 Zurich, Switzerland; firstname.lastname@example.org.