OBJECTIVETo investigate flap survival after transfection using gene encoding vascular endothelial growth factor (VEGF).

METHODSIn 30 Sprague-Dawley rats, the anterior abdominal skin flap supplied by the epigastric vessels was created. The animals were divided into three groups, with ten of each. The first group was treated with a mixture of liposomes and the cDNA encoding the 165-amino acid isoform of VEGF; the second group was treated with control blank plasmid DNA and liposome transfection medium; the third group was treated with physiological saline. Four days after injection, the epigastric artery and vein were ligated and the blood flow in the flap was evaluated by intraperitoneal injection of fluorescence solution. Seven days later, the survival area of the flap was measured by planimetry. After the animals were killed, specimens were harvested from the anterior abdomen skin flap for immunohistological evidence of VEGF expression and for hematoxylin and eosin staining of microvascular growth.

RESULTS30 minutes after pedicle ligation the average fluorescence staining planimetry of the three groups (PCD-VEGF165, PCD and physiological saline) was 60.64%, 30.15% and 29.89% respectively. Tissue survival planimetry of the three groups was 92.3%, 30.5%, 31.8%. There was significant difference between the first group and the latter two (P < 0.05). Immunohistochemical staining documented increased deposition of VEGF cDNA in the first group compared to the control groups (P < 0.05). Normal staining documented that the average vessel number of the three groups was 101.72, 91.35 and 89.85 (P < 0.05), the average vessel lumen diameter was 26 microns, 31.09 microns and 32.51 microns(P < 0.05).

CONCLUSIONThrough administration, PCD-VEGF165 can transfect the anterior abdominal skin flap and enhance its survival. There was express of VEGF protein in the treated flap.