Murakami Maki, Wiley Lara A, Cindrick-Pounds Lori, Hunter Glenn C, Uchida Tatsuo, Killewich Lois A
Section of Vascular Surgery, Department of Surgery, and the Office of Biostatistics, University of Texas Medical Branch, Galveston 77555, USA.
J Vasc Surg. 2002 Nov;36(5):917-21. doi: 10.1067/mva.2002.128940.
External pneumatic compression (EPC) devices prevent lower extremity deep venous thrombosis (DVT) by reducing stasis. There is a widely held belief that they also enhance endogenous fibrinolysis; however, recent studies of tissue plasminogen activator (the primary activator of fibrinolysis) and plasminogen activator inhibitor-1 (the primary inhibitor of fibrinolysis) failed to confirm this. The hypothesis of this study was that EPC devices increase the level of urokinase plasminogen activator (uPA), a second activator of fibrinolysis. This was a prospective trial in which 44 subjects who underwent major abdominal surgery were randomized to receive unfractionated heparin injections, thigh-length sequential EPC devices, or both for DVT prophylaxis. Prophylaxis was begun immediately before surgical incision and continued until postoperative day 5 or discharge. Venous blood samples were collected from an antecubital vein for measurement of systemic uPA levels and from the common femoral vein for measurement of regional uPA levels. Samples were collected the day before surgery, after induction of anesthesia but before surgical incision, and on postoperative days 1, 3, and 5. uPA levels (ng/mL) were measured with an enzyme-linked immunoassay. Baseline uPA levels (0.41 to 0.56 ng/mL; P >.05, analysis of variance with repeated measures) were similar among the three groups. uPA levels did not change after surgery in systemic or regional blood samples in any group. There were no significant differences in systemic or regional uPA levels in the groups treated with EPC devices relative to those treated with heparin at any time point (P >.05, analysis of variance with repeated measures). Enhancement of fibrinolysis with EPC devices remains unproven; the findings reported here suggest that effective DVT prophylaxis can only be assured when the devices are used in a manner that reduces venous stasis.
外部气动压迫（EPC）装置通过减少血液淤积来预防下肢深静脉血栓形成（DVT）。人们普遍认为它们还能增强内源性纤维蛋白溶解；然而，最近关于组织型纤溶酶原激活剂（纤维蛋白溶解的主要激活剂）和纤溶酶原激活剂抑制剂-1（纤维蛋白溶解的主要抑制剂）的研究未能证实这一点。本研究的假设是，EPC装置会增加纤溶酶原激活剂（uPA）的水平，uPA是纤维蛋白溶解的另一种激活剂。这是一项前瞻性试验，44名接受腹部大手术的受试者被随机分为三组，分别接受普通肝素注射、大腿长度的序贯EPC装置或两者联合用于预防DVT。预防措施在手术切口前立即开始，并持续至术后第5天或出院。从前臂静脉采集静脉血样以测量全身uPA水平，从股总静脉采集血样以测量局部uPA水平。在手术前一天、麻醉诱导后但手术切口前以及术后第1、3和5天采集样本。使用酶联免疫测定法测量uPA水平（ng/mL）。三组的基线uPA水平（0.41至0.56 ng/mL；P>.05，重复测量方差分析）相似。任何一组的全身或局部血样中，uPA水平在手术后均未发生变化。在任何时间点，使用EPC装置治疗的组与使用肝素治疗的组相比，全身或局部uPA水平均无显著差异（P>.05，重复测量方差分析）。EPC装置增强纤维蛋白溶解作用仍未得到证实；此处报告的结果表明，只有在以减少静脉淤积的方式使用该装置时，才能确保有效预防DVT。
