Arnljots B, Wieslander J B, Dougan P, Salemark L
Department of Plastic and Reconstructive Surgery, Malmö General Hospital, Sweden.
Microsurgery. 1991;12(5):332-9. doi: 10.1002/micr.1920120504.
In a blind randomized study, two groups of six rabbits were treated with either the fibrinolytic inhibitor tranexamic acid, 14 mg/kg bw, or isotonic saline solution (control group) given intraaortically as single bolus injections 5 min prior to arteriotomy and intimectomy of central ear arteries. Arteriotomic bleeding times, accumulations of 32P-labeled platelets, patency, and sizes of thrombus deposits 2 hr after reperfusion were recorded. Fixed vessels were observed by scanning electron microscopy. Bleeding times were similar in the two groups. The patency rate in the tranexamic acid group was 2/12, i.e., a significant reduction (P less than 0.05) from 7/12 in the control group. Thrombus deposits in occluded vessels contained large amounts of fibrin and red cells. Platelet accumulations in occluded vessels were significantly lower in the tranexamic acid group than in the control group, which indicates that the ratio of fibrin to platelets was increased in thrombi formed during antifibrinolytic treatment. This study has demonstrated the importance of normal fibrinolytic capacity in limiting thrombus formation following microarterial trauma. It is suggested that the use of antifibrinolytic agents in microvascular surgery should be restricted.
在一项双盲随机研究中，两组各6只兔子分别接受如下处理：一组静脉注射纤溶抑制剂氨甲环酸，剂量为14 mg/kg体重；另一组静脉注射等渗盐溶液（对照组）。给药时间均为在对中耳中央动脉进行动脉切开术和内膜切除术之前5分钟，采用单次大剂量注射方式。记录动脉切开后的出血时间、32P标记血小板的聚集情况、再灌注2小时后的通畅率以及血栓沉积物大小。对固定后的血管进行扫描电子显微镜观察。两组的出血时间相似。氨甲环酸组的通畅率为2/12，即与对照组的7/12相比有显著降低（P<0.05）。闭塞血管中的血栓沉积物含有大量纤维蛋白和红细胞。氨甲环酸组闭塞血管中的血小板聚集明显低于对照组，这表明在抗纤溶治疗过程中形成的血栓中纤维蛋白与血小板的比例增加。本研究证明了正常纤溶能力在限制微动脉创伤后血栓形成中的重要性。建议在微血管手术中应限制使用抗纤溶药物。
