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Prospective, Randomized Study of Two Intermittent Pneumatic Compression Devices for DVT Prophylaxis After Total Knee Arthroplasty
Source:
Lachiewicz PF: Presented at AAOS, Hip and Knee Society, Specialty Day, San Francisco, CA, 2004 and at the Knee Society, Chicago, Illinois, 2003
Summary:
The ideal operating parameters of IPC devices for the prevention of DVT following total knee arthroplasty have not been proven. This prospective, randomized study compared an asymmetrical calf compression device providing rapid impulse inflation (Device V) to a circumferential calf compression device (Device S) using gradual inflation.

The hypothesis maintained that the device providing the greater increase in peak venous velocity would result in a lower incidence of thromboembolism. The study included 423 patients totaling 472 knees who had primary or total knee arthroplasty across two surgeons at one institution. Sealed envelopes were used to randomize the patients and experienced technicians utilized duplex ultrasonography to detect the presence of thrombi. The technicians were unaware of the device used.

In total, 206 patients (232 knees) were treated with Device V and 217 patients (240 knees) with Device S. The incidence of venous thromboembolism was 6.9% (16 thrombi in 232 knees) with Device V as opposed to 15% (36 thrombi in 240 knees) with Device S. This difference was statistically significant (p=.005). There were no deaths or pulmonary embolisms with Device V compared to one death (.2%, myocardial infarction) and one pulmonary embolism (.2%) with Device S.

In unilateral primary knees the incidence of thrombi was 8.4% with Device V compared to 15.8% with Device S (p=.032). In bilateral knee patients, the incidence of thrombi was 4% with Device V compared to 22.7% with Device S (p=.096 per patient; p=.05 per knee).

Overall, there is a low incidence of death and pulmonary embolism using intermittent pneumatic compression and aspirin. However, the device utilizing rapid impulse inflation and asymmetric compression had a significantly lower incidence of thromboembolism than the device utilizing circumferential compression and gradual inflation.