The European Medicines Agency is preparing to issue an opinion on Thursday on a possible link between AstraZeneca’s Covid-19 vaccine and cases of venous thrombosis. What is it exactly? What are the risks of this blood clot forming?
In France, almost 100,000 phlebitis – also known as venous thrombosis – are detected every year. These are characterized by the formation of a blood clot in the veins of the lower extremities. Some are superficial because they affect small caliber veins found in the subcutaneous tissue. On the other hand, if it is deep phlebitis, it is larger caliber veins that are inserted near the arteries in the heart of the muscles of the leg. In this case, there is a significant risk of serious complications.
In fact, “the clot can break loose and cause pulmonary embolism (obstruction of the pulmonary artery),” Inserm describes. This is a vital emergency because it “damages the affected lungs and prevents the injured part from supplying oxygen to the body,” says Medicare.
React and prevent
Certain symptoms related to phlebitis should alert and encourage urgent medical treatment: redness, edema, pain in the leg or calf. But they are not systematic and “phlebitis can even be asymptomatic,” recalls Inserm.
Although there is as yet no cause and effect relationship between the AstraZeneca vaccine against Covid-19 and the risk of thrombosis, other risk factors are well known:
– surgery, if it is associated with permanent immobilization;
– trauma to the legs due to immobilization or installation of a plaster cast;
– stay in bed for several days;
– an infectious disease, lung or heart problem …;
– pregnancy and especially the weeks after the birth (especially in the case of caesarean section or complications);
– Long-distance travel without getting up …
– the tobacco.