Abstract
Background Ischemia-reperfusion (I/R) injury is inevitable during free tissue transfers. When
the period of ischemia exceeds the tissue tolerance, it causes necrosis and flap failure.
The aim of this study was to investigate the effects of adipose-derived stem cells
(ASCs) embedded in a collagen type I scaffold on the survival of free skin flaps to
counteract I/R injury.
Methods Left superficial caudal epigastric skin flaps (3 × 6 cm) were performed in 28 Wistar
rats that were divided into four groups. The flaps elevated in the animals of the
control group did not suffer any ischemic insult, and the vascular pedicle was not
cut. All other flaps were subjected to 8 hours of ischemia prior to revascularization:
I/R control group (8 hours of ischemia), I/R scaffold group (8 hours of ischemia + collagen
type I scaffold), and I/R scaffold–ASCs group (8 hours of ischemia + collagen type
I scaffold with rat ASCs embedded). Transit-time ultrasound blood flow measurements
were performed. After 7 days, the areas of flap survival were measured and tissues
were stained with hematoxylin/eosin and Masson's trichrome stain for histological
analysis.
Results The mean percentage flap survival area was significantly higher in the ASCs-treated
flaps (I/R scaffold–ASCs group) compared with the ischemic controls (I/R control group
and I/R scaffold group). Higher vascular proliferation and lower severity of necrosis
and inflammatory changes were seen histologically in the samples of the ASCs-treated
group. No significant difference in blood flow was detected between groups.
Conclusion Subcutaneous administration of ASCs embedded on a collagen type I scaffold reduces
tissue damage after I/R injury in microvascular free flaps.
Keywords
ischemia - reperfusion - mesenchymal stem cells
