Objective To improve the success rate of the reverse fascio-cutaneous flap in repairing the infected wound, to observe the effect of surgical delay on the anti-infection abil ity of the reverse fascio-cutaneous flap by establ ishing an oryctolagus cuniculus model of reverse fascio-cutaneous flap based on sural nerve on the lateral side of left later l imb. Methods Sixteen 5-month-old Japanese white rabbits weighing 2.0-2.5 kg (mean, 2.3 kg) were randomly divided into experimental group (n=8) and control group (n=8). The reverse fascio-cutaneous flap of 4 cm × 2 cm was designed, based on 1 cm above the lateral malleolar as pedicle in sural nerve region in the lateral left later l imb. In the experimental group, thefull-thickness of the flap distal end half was harvested according to the design; and after 10 days delay, the full-thickness flap was obtained according to the design, and 0.5 mL staphylococcus aureus solution was implanted at a density of 3.8 × 106 /mL in 2 groups. The general observation was performed postoperatively; the venous blood of the marginal ear vein was collected to observe white blood cell (WBC) count before implantation of staphylococcus aureus solution and after 1, 3, 5, 7, 10, and 14 days of implantation. The flap survival rate and the colony counting of necrosis flap tissue were calculated after 10 days of implantation; the blood vessel cal iber and the peak value of peroneal artery blood flow of flap proximal end were measured after 14 days of implantation. Results All animals survived to the end of the experiment, and all incisions healed primarily. Inflammatory reaction with different degrees was observed after implantation in 2 groups, and it was obvious at 3-5 days. Inflammatory reaction in the experimental group was sl ighter than that in the control group. Except for no significant difference before implantation and after 14 days of implantation between 2 groups (P gt; 0.05), there were significant differences in WBC count at other time points between 2 groups (P lt; 0.05). The flap survival rate of the experimental group (93.20% ± 4.62%) was significant higher than that of the control group (72.65% ± 7.80%) after 10 days of implantation (P lt; 0.05). The colony counting of necrosis flap tissue in the experimental group [(20.63 ± 5.76) × 103 colony/g] was significantly lower than that in the control group [(32.38 ± 6.14) × 103 colony/g] after 10 days of implantation (P lt; 0.05). The blood vessel cal iber of the experimental group and the control group were (1.03 ± 0.10) mm and (0.75 ± 0.09) mm, respectively, and the peak value of peroneal artery blood flow in the experimental group and the control group were (20.73 ± 2.46) cm/s and (13.83 ± 1.51) cm/s, respectively, after 14 days of implantation; showing significant differences between 2 groups (P lt; 0.05). Conclusion Surgical delay has the abil ity of enhancing survival and anti-infection of the rabbit reverse fascio-cutaneous flap.
Objective To investigate the effect of the vascular endothelial growth factor (VEGF) gene therapy, the surgical delay, and the combination of the two therapeutic approaches on the survival of the rat over-area abdominal axial skin flap. Methods In 48 male Wistar rats (weight, 400-450 g), a model of the abdominal axial skin flap supplied by the superficial epigastric blood vessel was created. The rats were randomly divided into 6 groups: Group A (the blank group), Group B (the gene-therapy-during-operation group), Group C (the gene-therapy-before-operation group), Group D (themerely-surgical-delay group), Group E (the gene-therapy-during-surgical-delay group), and Group F (the gene-therapy-aftersurgical-delay group). Seven days after operation, the survival rate of the skin flap was measured; the specimens were harvested from the skin flap for a histological investigation of themicrovessels and for an immunohistochemical staining to observe the expression of VEGF165. Results The average survival rate of the skinflap was significantly greater in each of the treated groups than in Group A (Plt;0.05); the rate was the greater in Group E (Plt;0.05), but with no statistically significant difference between the other treated groups (Pgt;0.05). The average number of the microvessels was significantly greater in Groups B, C, E andF than in Groups A and D (Plt;0.05), but with no statistically significant difference between Groups B, C, E and F and between Groups A and D (Pgt;0.05). The lumen diameter of the microvessels was significantly greater in Group D than in Groups E and F (Plt;0.05), and the diameter was significantly greater in Groups D, E andF than in the other groups (Plt;0.05). More deposition of VEGF DNA detected by the immunohistochemical staining was in Groups B, C, E and F than in Groups A and D. There was no newly-formed blood vessel in the rat cornea in the treated groups.Conclusion Both the administration of pcDNA4-VEGF165 and the surgical delay can improve the survival of the rat abdominal axial skin flap, but the mechanism of the effect is different in explanation. The combination of the two therapeutic approaches can achieve a better effect.