Learn more about Deep Vein Thrombosis
Watch videos from our specialist, Professor Sérgio Sampaio, and learn more about the symptoms and treatments for this venous disease.
What is Deep Vein Thrombosis?
Deep vein thrombosis (DVT) is the occlusion of a vein in the deep venous system, which almost always occurs in the lower limbs or pelvis, and occurs due to blood clotting inside the vein.
What are the symptoms of Deep Vein Thrombosis?
This condition may be asymptomatic, depending on the location of the affected vein.
Generally, the higher the affected vein is (in the pelvis, groin, and thigh), the greater the likelihood of it being symptomatic.
When it occurs in more distal areas, that is, further away from the groin area (such as the knee or near the ankle), it may be much less symptomatic.
The main symptoms include:
- Local pain in the thrombosis area;
- Significant feeling of tension and heaviness;
- Swelling of the lower limb;
- Color changes almost always between purple and reddish.
Risk Factors
Globally, we can divide risk factors into:
Congenital factors
These factors are called thrombophilias.
That is, specific genetic alterations in our blood coagulation system, which make certain people more prone to the formation of blood clots in their veins.
They almost always result from small defects in proteins that exist in circulation.
Acquired factors
They can result from diseases acquired throughout the patient's life, most notably oncological diseases. Virtually all types of cancer, as well as their respective treatments, increase the risk of deep vein thrombosis.
On the other hand, there are also other trivial factors such as:
- Overweight;
- Prolonged immobilization as a result of an illness or surgical intervention that has led to electrification, forcing the individual to remain still for a long time;
- Other situations in which a person spends many hours with their lower limbs in a retracted position with flexion, such as long-haul airline flights in economy class. Essentially, any time they spend many hours without moving their limbs in positions that favor the "stagnation" of blood in the venous bed.
Treatment of Deep Vein Thrombosis
Treatment may vary depending on the patient's characteristics:
- Age;
- Existence of other pathologies (cardiac or respiratory);
- Even after the acute phase, if necessary and possible, there may be something to offer. For an occluded or constricted vein, recanalization and dilation are sometimes recommended, keeping it open by placing a metal mesh cylinder (stent). This procedure aims to relieve symptoms and prevent Post-Thrombotic Syndrome.
Depending on the weight of these factors, treatment is decided through:
Drugs
Anticoagulant drugs may be indicated, which make the blood more “liquid” and “less viscous” and prevent thrombi from increasing in size, or drugs that aim to actively break up the existing thrombus.
Mechanical or pharmacomechanical means
These methods actively remove the thrombus by instilling drugs into it to speed its elimination. Devices can also be used to aspirate, break up, and remove the thrombus from its site.
What are the risks of Deep Vein Thrombosis (DVT)?
Normal vein circulation returns to the heart. In other words, blood ascending from the lower limbs travels to the right side of the heart and from there to the lungs.
In practice, this means that the first vascular bed with progressively smaller vessels encountered by a possible embolus that comes loose from the lower limbs is in the lungs.
This is why, in most cases, with very specific exceptions, a thrombus that comes loose from a DVT in the lower limbs can lodge in a pulmonary artery, giving rise to a pulmonary embolism.
If this happens, very specific symptoms occur, such as chest pain and, above all, shortness of breath.
In this case, the patient may be in imminent danger to his life and must go to the hospital immediately.
Deep vein thrombosis can also have long-term consequences, many years after it occurs. In fact, the affected veins may see their function permanently compromised:
- Remaining occluded or stenosed (tight);
- Losing valve function, thus allowing pathological venous reflux in an inferior direction.
When this happens, a progressively worsening condition called Post-Thrombotic Syndrome can develop. The limb in question becomes or remains edematous, and complaints of tension, heaviness, and fatigue become increasingly significant. The skin structure around the ankles, in particular, undergoes significant changes: mottled, atrophic, and fragile. Ulcers may eventually develop, which are extremely difficult to heal and tend to recur.
Specialist Doctor
in Deep Vein Thrombosis
Prof. Doctor Sergio Sampaio
- Graduated from the Faculty of Medicine of the University of Porto
- PhD from the Faculty of Medicine of the University of Porto
- Specialist in Angiology and Vascular Surgery
- Fellow of the European Board of Vascular Surgery
English (UK)