Ricci MA, Fisk P, Knight S, Case T.
Hemodynamic evaluation of foot venous compression devices.
J Vasc Surg 1997 Nov;26(5):803-8

Division of Vascular and Transplant Surgery, University of Vermont College of
Medicine, Burlington, USA.

PURPOSE: Venous compression devices effectively prevent deep venous thrombosis.
Recently, because traumatic injury of the limb often precludes application of
calf devices, newer methods have been developed that are only applied to the
foot. This study was designed to evaluate the venous hemodynamic effects produced
by four different compressive devices compared with calf-only intermittent
pneumatic compression (IPC). METHODS: Twenty-seven healthy volunteers had
application of each device followed by duplex scanning determination of the
venous hemodynamics at the popliteal vein (PV) and the common femoral vein (CFV).
Endpoints included (1) resting (peak) systolic velocity (RSV); (2) maximum venous
velocity (MVV) during device activation; (3) acceleration, the slope of the line
from RSV to MVV; and (4) return time (RT) from MVV back to RSV. The devices
evaluated included two commercially available mechanical foot devices, (1) foot
compressive device (FCD1), and (2) FCD2; (3) an experimental mechanical foot
device (FCD3); (4) an experimental pneumatic foot device (FCD4); and (5) a
calf-only IPC device (IPC). RESULTS: The RSV was higher in the CFV than the PV.
The initial RSV was not statistically significant between the five experimental
groups (p = 0.37) at either the PV or CFV, although the RSV was higher in the CFV
than in the calf (CFV, 24.3 +/- 6.7 cm/sec; PV, 12.5 +/- 3.7 cm/sec; p < 0.0001).
MVV was significantly higher with FCD2 and the IPC (p = 0.0002) at the PV level,
but this difference decreased at the CFV. Acceleration was greatest with the two
available foot devices, FCD1 and FCD2, compared with the other three devices (p <
0.0001) at both levels. On the other hand, the RT was significantly longer only
with the IPC; RT was four to 10 times slower at the PV and three to five times
slower at the CFV compared with the other four devices. CONCLUSIONS: The two
commercially available foot devices, FCD1 and FCD2, and the IPC produced
significant alterations in venous hemodynamics. Changes produced at the PV level
by both foot and calf devices were seen proximally at the CFV, although the
changes were usually less. The mechanical devices produced rapid acceleration of
venous flow to an elevated MVV, whereas the IPC produced an elevated peak with a
sustained period of flow above baseline (RT). Further clinical comparison should
be completed before widespread adaptation of these devices as an equivalent to
existing IPC devices.