ABSTRACT
This study examined the efficacy of gene therapy on wound healing. The authors investigated
whether delivery of the gene encoding a particular cytokine, known to be important
in angiogenesis, could affect ischemic skin flaps. Anterior abdominal skin flaps,
based solely on the epigastric artery and vein, were created in the Sprague-Dawley
rat model. At the time of elevation, the arterial pedicle supplying each flap was
infused either with the gene for vascular endothelial growth factor (VEGF) or physiologic
saline alone. The flaps were resutured into place and observed for a period of either
4 or 3 days, at which time the pedicle was ligated. Twenty minutes following ligation,
blood flow in the flaps was measured by dye fluorescence. Tissue viability of the
flaps was subsequently measured by planimetry after a period of 7 days. Flaps that
received the VEGF gene and were ligated at 4 days had an average dye fluorescence
index (DFI) of 31.1 following ligation, and 93.9 percent viable tissue after 7 days.
Flaps that received saline alone, and were ligated following a similar interval, had
an average DFI of 14.0 and 31.9 percent viable tissue. Among the subjects that were
ligated at 3 days, only a single, gene-infused flap had any noticeable viable tissue
after 7 days. The DFI of these groups was 11.0 for the gene-infused group and 22.1
for the saline-infused group. The results suggest that delivery of the gene for VEGF
can improve the survival of ischemic skin flaps, but that the effect of gene therapy
is not limitless.
