Postoperative deep vein thrombosis, or DVT, is a serious, potentially life-threatening condition. It affects a broad spectrum of patient populations, and is the single most common fatal complication of surgery and hospitalization.

What are DVT and PE?

DVT, or deep vein thrombosis, is the formation and release of blood clots (thrombi) inside the deep veins, most often in the legs. PE (pulmonary embolism) occurs when one of these thrombi becomes lodged in the lungs. Together, these conditions are referred to as VTE, or venous thromboembolism. DVT can cause significant, crippling damage. PE is a life-threatening event.


Causes

Changes in intrathoracic pressure associated with anesthesia and surgical procedures can reduce venous return from the extremities to the heart.
Surgical and therapeutic trauma can set up a chemical “chain reaction” that causes proliferation of clotting factors in the deep veins.
And, most importantly: Patient immobility, for hours, days, or weeks, enhances venous stasis because the “muscle pump” and “foot pump” of the legs, which are activated by physical activity, are in disuse.

The muscle pump and foot pump

Blood flow in the deep veins is significantly affected by physical activity. The deep veins are surrounded by muscles that press against the vein walls. As the muscles contract and extend during normal physical activity, the veins are compressed, causing the blood inside them to flow towards the heart. One-way valves inside the veins keep the blood from moving in the wrong direction.

Two powerful mechanisms for propelling this venous blood are the calf muscles on the back of the lower leg (the "muscle pump"), and the vein bed located on the sole of the foot (the "foot pump"). When you walk, the veins on the sole of the foot are compressed and released. This “pumping” action squeezes the blood inside the veins upwards, to the heart. At the same time, the powerful muscles on the back of your lower leg contract and extend, applying and releasing pressure to the veins of the legs, also propelling the venous flow. In fact, the blood-moving action of the “muscle pump” is so effective that this mechanism is often called the “peripheral heart.”


Click the image above to see how the foot and muscle pumps work to increase venous blood flow

When a patient is immobile for long periods, such as during and after surgery, recovering from injury, or as a result of illness or stroke, the "muscle pump" and "foot pump" are in disuse. Under these conditions, venous blood may stagnate in the legs, allowing clots to form. Other risk factors aside from immobility may further increase risk of clot formation.

Did you know?
 DVT occurs in 2 million Americans each year.
 DVT is a major complication in orthopedic surgical patients.
 Each year 600,000 patients in the USA develop PE, and 10% of these will die as a result.
 More American women die each year from PE than from breast cancer!
 In the USA, PE is the most frequent cause of death associated with childbirth!


DVT prevention

DVT and PE can both be effectively treated, but prevention is by far the best method of defense. Phlebo Press DVT is an intermittent sequential compression therapy device (IPC) for prevention of postoperative deep vein thrombosis. It works by mimicking the action of the muscle pump and the foot pump on the veins of the leg by applying pressure, first to the sole of the foot, and then sequentially up the calf. The sleeve then deflates, allowing the veins to refill. This cycle repeats once every 60 seconds.