Effects Of RhEPO And HBO On The Survival Rate Of Rat Ultra-long Ischemic Dorsal Skin Flap

Objective:Recombinant human erythropoietin (rhEPO) can induce the differentiation of endothelial progenitor cells into new endothelial cells. Hyperbaric oxygen (HBO) provides enough oxygen for the proliferation of new endothelial cells and accelerates the occurrence of new endothelial cells. We designed the following experiment to analyze the effects of rhEPO, HBO and their combination on ultra-long ischemic dorsal skin flap in rats.Materials and Methods:A long ischemic free skin flap was made on the back of each rat at 4:1, and assigned into 4 groups. Rats were treated with saline plus normal pressure oxygen (normal pressure oxygen group), HBO plus saline (HBO group), rhEPO plus normal pressure oxygen (rhEPO group), normal pressure oxygen plus rhEPO (combination group). The dosage of intervention: subcutaneous use of rhEPO (400 IU/kg) or saline equals to rhEPO in volume, once a day, for 10 days; HBO (202.65 kPa, 95% oxygen concentration) or normal pressure oxygen (101 kPa, 35% oxygen concentration), once 1 hour, twice a day, for 10 days. Oxygen was given 8 hours following suture. The survival rate of skin flap was measured at day 10 after suture. VEGF and CD34 of histological specimens were used as vascular marker to determine the level of microvessel density.Results:Qualitative analysis: Local necrosis and gland atrophy were detected in the normal pressure oxygen group.Histological check: Good gland morphology was seen in the HBO group. Gland hyperplasia was found in the rhEPO group, and the hyperplasia was more significant in the combination group.Quantitative analysis: Compared with the normal pressure oxygen group, microvessel density value was increased in the HBO group, rhEPO group and combination group (P <0.01), in a tendency to increase. According to a=0.05, significant differences were detected among groups (P < 0.01). Results of analysis of variance showed that rhEPO and HBO had synergistic effects, and their combination could obtain good outcomes.Conclusions:The use of rhEPO, HBO and their combination can upregulate the microvascular density in ischemic skin flap, also can expand the ratio in random skin flap. The rhEPO has better therapeutic effects than HBO, and their combination have the optimal therapeutic effects in the ischemic skin flap.