[Effect of Natural Hirudin on Revascularization of Ischemic Skin Flaps in Rats by Micro-CT].

OBJECTIVE:To investigate the effect of natural hirudin on revascularization of ischemic skin flap in rats using Micro-CT and three-dimensional (3D) reconstruction.METHODS:Thirty-two Sprague Dawley rats were prepared a ischemic skin flap (8.0 cm×1.8 cm) model on the back and randomly divided into hirudin group and control group (16 rats in each group). At immediate and within 3 days after operation, the rats were treated with hypodermic injection of natural hirudin 0.3 mL (including natural hirudin 6 ATU) every day in hirudin group and the equal amount of normal saline in control group. At 6 days after operation, the survival rate of skin flap was evaluated, histological changes were observed by HE staining, and the volemia, length of blood vessels, and number of blood vessels were analyzed with Micro-CT 3D reconstruction.RESULTS:Both groups of rats survived to the end of the experiment without infection. Different degrees of necrosis occurred in the distal part of the skin flaps in both groups at 6 days after operation, but the flap survival rate of the hirudin group (72.11%±8.97%) was significantly higher than that of control group (58.94%±4.02%) ( t=3.280, P=0.008). Histological observation showed that the histological hierarchy of the hirudin group was clearer than that of the control group, with more microangiogenesis and less inflammatory response and inflammatory cell infiltration. Micro-CT 3D reconstruction showed that the flap vessels in the hirudin group were more and denser, and the volemia, length of blood vessels, and number of blood vessels were significantly higher than those in the control group ( P<0.05).CONCLUSION:Natural hirudin can reduce the inflammation of tissue, promote the regeneration and recanalization of blood vessels in ischemic skin flap, so as to improve the survival rate of the flap.