Reference Search

The 100 participants (50 study, 50 control) received hypotensive epidural anesthesia and 325 mg. of aspiring (ASA) twice daily. The control group wore elastic stockings while the study group utilized the VenaFlow calf device. Statistically significant results were found: 22% (11) in control group developed DVT while only 8% (4) in the VenaFlow study group. In addition, the rate of occlusive clots which obstruct blood flow was significantly higher (10% stocking group) vs. only 2% in the VenaFlow group. No clinically symptomatic DVT or pulmonary embolism were noted in either group.

MRV visualizes clots that are not seen on less sensitive tests like venography or duplex Doppler ultrasound. Clots near the hip and pelvis can be detected even if the patient has undergone a total hip arthroplasty. Many of the clots that are visualized on MRV would not be visualized on traditional venography or ultrasound. Authors note in two previous studies IPC showed a decrease in distal DVT but an increase in proximal DVT. The authors feel this may be attributed to older forms of pneumatic compression with lower stroke volumes as well less sensitive screening techniques.

The authors conclude, “The VenaFlow mechanical compression device used in the present study provides a rapid impulse inflation compressing the calf veins through two overlapping air cells every sixty seconds. The asymmetrical compression maximizes blood velocity and total blood flow, which results in greater venous ejection compared with that provided by circumferential compression. Additionally, the inflation rate has a profound effect on venous velocity. In a previous comparative study of venous hemodynamics after total joint arthroplasty, the VenaFlow was noted to increase peak venous velocity at the level of the common femoral vein by almost 300% above the baseline, which was the greatest increase offered by the devices that were studied.”