| Objectives: To evaluate the changes of mechanical parameters of the injured femoral artery in rabbits by velocity vector imaging(VVI).Try to explor a new ultrasonic method of quantification assessment for diagnosing injured femoral artery.Methods:1. To explore the method to establish animal model of injured superficial femoral artery in rabbits. Tow means of embolectomy catheter and remodified guide wire were used to establish animal model of injured superficial femoral artery and the embolectomy catheter was implanted into superficial femoral artery through surgical intervention and arteriopuncture respectively.The effective method was selected according to histopathological results . A total of 6 New-Zealand rabbits were divided randomly into groups A,B and C.In group A ,the embolectomy catheter was implanted into superficial femoral arteries through surgical intervention and 0.20ml air was injected into the balloon. In group B, the embolectomy catheter was implanted into superficial femoral arteries through arteriopuncture and 0.20ml air was injected into the balloon. In group C,the remodified guide wire was implanted into superficial femoral arteries through arteriopuncture.2. To evaluate the changes of the injured superficial femoral arteries with color Doppler ultrasonography(CDU) and VVI.A total of 20 New- Zealand rabbits were divided randomly into the control group (5 rabbits) and experimental group (15 rabbits ).In the injured group, the superficial femoral arteries were injured with remodified guide wire what was implanted through arteriopuncture.In the control group, remodified guide wire was not implanted. A dedicated commercial VVI workstation was employed for the off-line tow-dimensional gray-scale short axis image analysis and the exploration of mechanical parameter changes of the femoral arteries.The maximum strain (Smax) , maximum strain rate (SR), peak systolic velocity(PSV) and the inner diameter of the superficial femoral arterial wall were detected in control group and injured group instantly, and 1 hours,3 hours,6 hours,9 hours,12 hours after injured.The injured segments of the superficial femoral arteries in experimental group were examinated histopathologically instantly, and 6 hours, 12 hours after injured. The corresponding segments in control group were examinated histopathologically12 hours after injured.Results:1. Remodified guide wire was more effective than embolectomy catheter to establish animal model of injured superficial femoral artery. Histopathological results demonstrated that the endarterium and tunica media of the injured superficial femoral artery were tore,and small haematoma could be found in group C. In group A and B,the animal model of injured superficial femoral artery could not be established effectively.2. The second part of the study showed the mechanical and haemodynamic parameters changed in the experimental group compared with control group.In the injured segment of the experimental group, the Smax evaluated instantly was lower than those 9 hours,12 hours after injured(P<0.05)and the Smax evaluted 9 hours,12 hours after injured were higher than those instantly ,1 hours,3 hours,6 hours after injured(P<0.05, P<0.05 respectively). The Smax of the the injured segment in experimental group at each time point was lower than those in the control group(P<0.01). The SR of the injured section showed no significant difference between the experimental group and control group(P>0.01)though the SR values dropped slightly after injured. All the PSV values of the injured segment were lower than those in control group(P<0.01)and the PSV values evaluated instantly and 1h after injured were lower than those 3hours,6hours,9hours and 12hours after injured (P<0.01, P<0.05 respectively). The inner diameter of the superficial femoral artery in experimental group was enlarged compared with those in control group(P<0.01)and the inner diameter values in experimental group evaluated instantly was lower than those 1 hours,3 hours, 6 hours, 9 hours, 12 hours after injured(P<0.01).Conclusion:1. In the injured segment of the experimental group, the deformability of the wall degraded what could be indicated by the dropping Smax values.2. Along with the time passage, the Smax in the injured segment of the experimental group increased gradually gave the cues that the deformability of the wall changed.3. The injury in superficial femoral artery could be illustrated by the changes in mechanical parameters.
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