The Effects Of Blood Flow Perfusion On Vascular Morphology And Tissue Metabolic In The Choke Vessels Of The Cross-flap

Objective: To investigate the effects of different degrees of blood perfusion on vascular morphology and metabolic changes in the central choke area of the cross-flap.Methods:100 healthy Balb/c mice weight 20-25 g were randomly divided into three groups.We established the mouse model of single dorsal perforator and multi perforator flap by ligating different numbers of perforating vessels.A crossed-flap measuring 5cm×3cm was elevated.Four perforators denoted as upper left?lower left?upper right?lower right,there is a mesh anastomosis in the central of flap,which was called the center choke area.Group A : ligated the right thoracodorsal perforator;Group : ligated both the right thoracodorsal and iliolumbar perforators;Group C : Only kept the left thoracodorsal intact,the rest of other three perforators were all ligated.The flap blood flow in the central choke area was monitored consecutively and dynamically after operating for day 1,day 3,day 7,day 10,and day 13.The vascular morphology characteristics and the microvessel quantity in the flap were observed by H.E and Masson stain.The glucose and lactate acid were detected by automatic biochemistry analyzer.ELISA assay shows the expression of VEGF and IL-1?.Results:(1)The characteristics of blood flow changes: each experiment group choke blood flow through the central region significantly different,from day 1to day 13 after operation,experimental A and B two groups of blood flow at each time point after operation showed a increasing trend.The blood flow in group C increased 1day after operation,then gradually decreased to the third day,and then gradually increased from day 7 to day 13.(2)The characteristics of vascular morphological changes: After operation,the blood vessel diameter of each group in the central choke area was expanded,we can see the increasing vascular curvature in zone C of experimental groups,and the increaed vascular curvature of pedicle is particularly evident on day 3postoperatively.HE and Masson staning showed the dilated diameter and thicken wall;the number of blood vessels in the experimental group C(15.65±0.46)was more than that of A(10.29±0.87)and B(11.24±0.37)on day 13.(3)Metabolic level: the level of glucose was gradually increased from the first day to the day 3 after the operation in each group,but the level of lactic acid was gradually decreased,but the level of lactic acid increased and the glucose level decreased after the operation form the day 3 to the day 7.the level of tissue glucose in group A decreased from day 7 to day 10,and tissue glucose levels increased from day day 10 to day 13.The levels of glucose in the other groups were gradually increased from day 7to day 13,especially in the group C.(4)The expression of cytokines: The expression of VEGF and IL-1? was significantly different.The protein content of VEGF was significantly increased in all groups on the day 3 and the day 13 after operation,but the expression of IL-1? was significantly different between the two groups,The expression of IL-1? in the experimental group C was lower than that in the experimental group A and the experimental group B.Conclusion:In the three kinds of surgical delay,the choke microcirculation of the single perforator flap was the best,which might be related to the decrease of the release of inflammatory factors and the promotion of angiogenesis.