Murakami M, Wiley LA, Cindrick-Pounds L, Hunter GC, Uchida T, Killewich LA.
External pneumatic compression does not increase urokinase plasminogen activator
after abdominal surgery.
J Vasc Surg 2002 Nov;36(5):917-21

Section of Vascular Surgery, Department of Surgery, and the Office of
Biostatistics, University of Texas Medical Branch, Galveston 77555, USA.

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.