Dr Paulino Souza Neto Vascular Surgery, Endovascular Surgery

English » Venous Diseases » DVT - Deep Venous Thrombosis

The Deep Venous Thrombosis (DVT) is a disease characterized by the formation of blood clots within the veins of the deep venous system (among the muscles).

In consequence to the venous obstruction caused by the clots, the blood remains dammed in the afflicted limb. The muscle swelling causes pain characterized as a weight or light cramp with sub-acute and progressive onset. After 1 or 2 days, the superficial veins are dilated in order to increase collateral drainage. The major concern on this event is the risk of the clot to dislodge, navigate through the vena Cava and the right side of the heart, into the Pulmonary Artery and it's branches. This is the Pulmonary Embolism and may lead to acute or chronic respiratory distress and even death. The causes that lead to the event should always be investigated and normally are a consequence of 2 or more factors acting together. They might be consequent to Pelvic Venous Compressions, Venous aneurisms, Thrombophilias, abdominal, orthopedic and gynecological post operatory and systemic diseases.  

The initial treatment of DVT is resting with the swollen limb elevated and the use of anticoagulants.

The sequels are more severe when occur at the level of the pelvis and calf. 

The anticoagulant therapy shall be maintained and monitored by your physician for at least 6 months. The major risk of Pulmonary Embolism (PE) occurs in the first 15 days of the onset of symptoms, and the patient shall remain in relative rest during such period. After it, the patient might gradually return to the usual activities after the physicians clearance.

Those activities shall not involve any risk of trauma since there is a risk of bleeding due to the use of anticoagulants.

There is also the alternative to destroy those clots through medications or mechanical actions alone or combined (Thrombolysis). A great advantage of this approach is the fast resolution of clinical symptoms, correction of Pelvic Venous Compressions and the prevention of late severe sequelae.  

Those sequelae occur  due to the valves reverse pressure overload in the whole distal venous system consequent to the proximal occlusion. When the thrombus in the deep venous system is  naturally destroyed in the process of recanalization, the valves may become insufficient, also contributing to the late sequelae. In order to protect those systems, the use of compressions stockings is indicated. The compressive therapy shall be routinely used until the circulatory conditions are reestablished. If any sequelae in the Deep Venous System remains, a prolonged compression therapy shall be maintained.

Whenever anticoagulant therapy cannot be implemented due to the risk of bleeding, or the need of a surgical procedure, there is the indication of Vena Cava Filter implantation. This device has the sole purpose to prevent the lethal Pulmonary Embolism but cannot prevent the thrombus propagation.

Pregnant women are a population in risk to DVT and when it occurs, a six month anticoagulation therapy is needed as well as a scheduled delivery. During pregnancy the therapeutic approach differs due to the needed attention to the fetus. Medication should preferably be with Heparins to prevent child malformation and the positioning of the Vena Cava filter shall be above the renal veins when needed, preferably a temporary one.  
The preventive treatment of the risk factors to DVT is the ideal approach!

Venous Thrombus Embolism in numbers:
* In the USA  2.000.000 cases of DVT occur yearly with 600.000 episodes of Pulmonary Embolism leading to a 100.000 deaths.
* Childs are also in risk of DVT that occurs approximately in 7 child per million  

* Maternal Death due to  Pulmonary Embolism occur in 10 mothers for each 100.000 live births.
* It is the 5th cause of maternal death in Brazil and the 3rd cause in México.
* The Pulmonary Embolism is letal in 10 to 15% of the medically treated patients and in 25 to 30% of the cases without anticoagulation.
* Hence the medically treated patients with DVT have an 80% reduction in the relative risk of Pulmonary Embolism.

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