| Objective:Subclavian artery injury in clinical practice is very common, and became more serious characterized by the increases. The causes are mainly severe car accidents, machines extrusion, gun shots and sharp instruments. Because of its close relations between Subclavian artery and brachial plexus, the special anatomic position, and restricted by microsurgical technique, it was discouraged to operate to repair the blood vessels early. But depending on the collateral circulation as Shoulder nets, the upper limb would not get general necrosis after the subclavian artery injury. The upper limb represents incomplete ischemia because of the blood-supply insufficiency, which displayed gradual fibrosis of Muscle and ischemia degeneration of the upper nerve. The upper limb appears serious function obstacle.This research establishes incomplete ischemia animal models in upper limb and does experiment examinations to compare the effect of brachial plexus and muscles during different periods of incomplete ischemia after subclavian artery injury. Discuss its function and the mechanism, provide the necessity to repair the subclavian artery and the theory guidance for the timing of clinical treatment and The prognosis of patients.Methods:Select 100 healthy SD big rats, body weight ranged 250 300g, sex randomly, divide them into 2 groups by random choice. (1) experimental group:50 rats. Expose the left subclavian artery, block the second section of subclavian artery with serrefine. Select 10 rats by random choice respectively about 1 hour,3 hours,6 hours,12 hours,30 hours after operation, which to be observed by the Electrophysiological studies. Then put the rats to death, take samples of the muscle and the nerve to observe under the light microscope with methods of HE and detect enzyme activity. (2) comparison group:50 rats. Expose the left subclavian artery only, not block the subclavian artery.Carry out the Electrophysiological studies. Then put the rats to death, take samples of the muscle and the nerve to observe under the light microscope with methods of HE and detect enzyme activity. Then a statistics analysis is carried out on each group of data.Results:1 Electrophysiologic study:due to the limited length of the samples taked in this experiment, the stimulating electrode is too close to the acceptive electrode, which will be easily influenced by the volume conduction, therefore, the incubation period data is taken to avoid the surface distance error, and the swing measurement can reflect the number of axons conducting the excitation. the incubation period of the experimental group is distinctively higher than those of the control group, P<0.05, the result of the experiment shows there is a substantial difference between the experimental group and the control group. The amplitude of the experimental group is distinctively higher than those of the control group. P<0.05, the result of the experiment shows there is a substantial difference between the experimental group and the control group.2 Na+-K+-ATP enzyme activity determination:mitochondria dysfunction due to the skeletal muscle ischemia, ATP generate inadequacy, so Na+-K+-ATP enzyme activity which rely on energy supply from ATP descend. The Na+-K+ ATP enzyme activity of the experimental group is distinctively lower than those of the control group, P<0.05, there is a substantial difference between the experimental group and the control group.3 Histological Examination3.1 Neuro-histological Examination:the light mirror observation on the samples,5 visions are taken randomly on each sample under the 400-time light microscope, measure the number of myelinated nerve, and the average value is taken and compared. The result shows that the number of myelinated nerve is not significant difference between the experimental group and control group (p>0.05).3.2 muscle-histological Examination:take the right forearm flexor to mearsure the cross sectional area of the muscular fiber, the result shows the figures is not significant difference between the experimental group and control group.Conclusion:1 Subclavian artery injury presents insufficient blood-supply, the skin temperature is low, red and white response become slow, but the upper limb won't be necrosis. The results of this experiment illustrate:after Subclavian artery injury, compensatory circulation which from shoulder nets can not offer adequate blood-supply, the upper limb performs incomplete ischemia.2 With the prolongation of ischemia time, electrophysiology examination showed that subclavian artery injury can cause brachial plexus ischemia, which appear as the amplitude brings down and the incubation period elongates,.But with the ischemia time prolong more, nerve conduction velocity will not slow further, which is considered as the tolerance of ischemic nerve.3 It is especially important to heal the injured blood vessels as soon as possible and facilitate the nerve regeneration and function recovery.
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