采用低分子右旋糖酐加蝮蛇抗栓酶对首次发作脑梗塞后的患者进行每年定期预防性治疗。经５ 年随访研究证明此方法可减低血液粘度， 维持纤维蛋白原和红细胞压积于正常水平， 减少脑梗塞复发的危险因素， 提高年生存率１０ ％ ～２０ ％ ， 复发率下降１４ ％ ～１７ ％ ， 经治疗后５ 年整体生存期延长 The use of low molecular weight dextran and viper antithrombin on the first episode of cerebral infarction patients after regular preventive treatment. After 5 years of follow-up study shows that this method can reduce blood viscosity, maintain normal fibrinogen and hematocrit, reduce the risk of recurrent cerebral infarction, improve the annual survival rate of 10% to 20%, the recurrence rate decreased 14% to 17 %, After 5 years of treatment the overall survival is extended