The therapy with rhVEGF gene for ischemic TRAM flap in rats / 中华整形外科杂志

ABSTRACT

<p><b>OBJECTIVE</b>To establish a stable ischemic TRAM flap model in rats and observe the effects of rhVEGF gene on the ischemic flap.</p><p><b>METHODS</b>Materials were administrated via subcutaneous injection 5 days before the TRAM flap procedure. 32 animals were divided into four groups. The first group was treated with PcDNA3.1 VEGF; the second group with PcDNA3.1 as the negative control; the third group with normal saline as the frank control, and the fourth group with VEGF as the positive control. The material was given while the procedures were performed. The serum levels of VEGF before and after the operation were measured with ELISA kit. The flap was harvested for immunohistological evidence of VEGF protein expression. The viable area of the flap was calculated with AutoCAD software. The microvessel density(MVD) of the subcutaneous tissue of the flap was counted.</p><p><b>RESULTS</b>The average viable area of the TRAM flap in model animals was (3.61 +/- 1.06) cm2 [(16.04 +/- 4.71)%]. Comparing the mean viable area of the flap in the PcDNA3.1 VEGF group[(7.98 +/- 2.64) cm2] with that in the normal saline group [(4.13 +/- 1.77) cm2], the difference was significant(P < 0.05). There was no significant difference between the PcDNA3.1 VEGF group and the VEGF group[(7.31 +/- 1.22)cm2] in terms of mean viable flap area. The difference of mean MVD values between the PcDNA3.1 VEGF group and the negative control group was significant(P < 0.05), but was not significant between the gene treatment group and the positive control group. The serum level of VEGF did not increase significantly up to 9 days after the administration of PcDNA3.1 VEGF(P > 0.05). Immunohistochemical staining documented the increased deposition of VEGF protein in the plasma of endothelial cells of the flap that was injected with PcDNA3.1 VEGF.</p><p><b>CONCLUSION</b>The unilateral inferior-pedicled TRAM flap as an ischemic flap model is stable and suitable for statistic treatment. Subcutaneous injection of rhVEGF gene can express biologically active VEGF at the site, increase MVD and the viable area of the TRAM flap.</p>