"Veno-Press"--a new sequential intermittent pneumatic device for the prevention of perioperative deep vein thrombosis

The prevention of peri-operative deep vein thrombosis (DVT) and the potentially hazardous pulmonary embolism that may follow is still a major medical issue. Intermittent pneumatic compression is one of the many methods currently in use for this purpose. No information is available, however, regarding the venous flow alterations that occur during employment of a pneumatic compression device under general anesthesia. The aim of this study is to delineate these venous flow variations and to determine the optimal pump setting for the prevention of operative venous stasis and its sequelae, postoperative DVT. A new sequential intermittent pneumatic device, the "Veno-Press", was applied on 20 volunteers of whom 10 were undergoing surgery unrelated to the lower limbs, during the pre-anesthesia and during general anesthesia. The venous velocity patterns over the femoral vein were depicted via duplex scanning under different pressure and rhythm settings of the device. The "Veno-Press" induced a marked augmentation in venous blood velocity flow. A further 10-30% augmentation was noted when the patients were under general anesthesia, as well as a 10-30% increase in the femoral vein diameter. None of the patients developed postoperative DVT. This device is a very efficient tool for augmentation of venous blood velocity, especially during general anesthesia. Its effectiveness is most probably the result of the compressive action over the relaxed--and hence enlarged--capacitant veins of the anesthetized patient. We suggest that the "Veno-Press", if properly timed, is very efficient in venostasis prevention, leading presumably to a decline in the occurrence of DVT and pulmonary embolisms in the surgical patient.