Tortuous, dilated leg veins further increase the likelihood of one of the most feared complications of coronavirus infection: thrombosis. Understand why it happens, the most common symptoms, and forms of treatment or prevention.
The days when covid-19 was considered only a respiratory disease are over. Nowadays, there is a consensus among specialists that the repercussions of infection by the coronavirus they are not limited to the lungs and can affect many other parts of the body, especially the blood vessels.
The risk of developing thrombosisthe formation of clots in the veins and arteries which can block blood flow and interrupt the supply of oxygen and nutrients to the organs, is much higher in infected patients, especially those with more serious conditions, which require hospitalization in an intensive care unit (ICU).
And, according to experts heard by BBC News Brasil, the likelihood of having this vascular complication during or after covid increases a little more in people who have varicose veins, a condition marked by the dilation and deformation of the most superficial veins. legs .
According to the Brazilian Society of Angiology and Vascular Surgery (SBACV), approximately 38% of Brazilians have varicose veins.
But what does one thing have to do with the other? And are there ways to prevent, detect early and treat covid-related thrombosis? To answer all these questions, we must first take a step back and understand how a virus that enters through the nose and mouth causes so many problems in the blood vessels.
Worse the amendment than the sonnet
Doctor Carlos Jardim, who works in the pulmonology division of the Instituto do Coração (InCor), in São Paulo, recalls that at the start of the pandemic the first suspicions appeared that the coronavirus could affect the veins and arteries. .
“We started to see a lot of thrombosis phenomena in patients who went to intensive care. The frequency was much higher than what we had seen in other respiratory virus epidemics, such as the H1N1 pandemic in 2009” , he said.
And the explanation for this has to do with an affinity that exists between Sars-CoV-2, the pathogen that causes covid, and the cells that form the inner layer of blood vessels, also known as the endothelium. .
These endothelial cells are now known to have the receptors the coronavirus attaches to to trigger infection. In practice, this means that it is also capable of wreaking havoc on this structure of the circulatory system.
“The endothelium must be very smooth, like the asphalt of a good road, so that the blood circulates without lumps”, explains pulmonologist Elnara Márcia Negri, of the Sírio-Libanês Hospital, in São Paulo.
“What happens in covid is that the virus manages to invade these cells and perforate this internal asphalt of our vessels”, adds the doctor.
The body, in an attempt to stop this problem, starts a series of processes and one of them involves blood clotting. The idea is to create a protective barrier in the injured region, so that the endothelium can recover.
The problem is that, in a number of patients, the amendment ends up being worse than the sonnet. The clotting mechanism passes the point and generates a jelly-like mass of cells and fibers that can stop blood flow there or break off and block circulation to other organs. We are talking here about thrombi.
“It’s like I’m fixing the wall of my house, but I’ve overdone the layer of cement so much that I can’t open or close the door anymore,” Jardim compares.
If the blockage occurs in the arteries of the heart, the heart attack. If the phenomenon takes place in any vessel of the head, we can have a stroke (stroke). Now, if the thrombus breaks free and ends up in the lungs, it’s called an embolism. All three situations are very serious, with a high risk of death.
“To complete, the critically ill patient is usually sedated and intubated. And this absence of body movement for a prolonged period is another risk factor for thrombosis”, adds vascular surgeon Fábio Rossi, president of SBACV – Regional of São Paulo Paul.
A survey published in July 2020 and signed by specialists from three Dutch hospitals revealed the frequency of thrombosis in hospitalized patients with severe covid.
Of 184 patients analyzed, 49% had thrombotic events. Of these, 87% were diagnosed with pulmonary embolism, 6.6% with stroke and 2.6% with arterial thrombosis.
Fortunately, the frequency of coronavirus-related thrombosis episodes has been declining in recent months.
“In our clinical practice, we have seen thrombotic events in 15% of patients, a number that has dropped to 2% more recently,” Negri calculates.
And it has to do with vaccines, which protect against the most severe forms of covid and its consequences throughout the body.
“The only patient I had the misfortune to intubate in this current wave of omicron had not been vaccinated,” reports the doctor.
And where do varicose veins fit into this story?
Well, now that we understand the relationship between covid and thrombosis, it’s time to add a third ingredient: varicose veins.
First of all, it should be clarified that there are not many studies examining this relationship. There is, for example, no calculation of the additional risk that carriers of this disease, marked by swollen and deformed veins in the legs, run of having a thrombosis, if they are infected with the coronavirus.
And it should be mentioned that the reverse path has not been observed so far: there is no scientific evidence that covid can be a trigger for the development of varicose veins.
For the moment, the appearance of varicose veins after covid is seen as an independent event and without a common denominator. In any case, it is worth seeking a doctor to assess the condition in a personalized way, if you have noticed something different in the blood vessels of the lower extremities.
The greatest risk of thrombosis during or after covid in those with varicose veins comes more from a practical observation of medical specialists in this field.
And, even before the pandemic, it was already known that varicose veins are an independent risk factor for the development of thrombosis.
A study published in 2018 in the specialized journal Journal of the American Medical Association (Jama), for example, followed for seven and a half years more than 212,000 people with varicose veins and 212,000 others who did not have this problem.
Comparing the results of the two groups, researchers from the Medical University of China found that the risk of thrombosis is 5.3 times higher in people with varicose veins.
If we bring this information to the context of the pandemic, therefore, varicose veins can be an additional ingredient which, together with the action of the virus on the endothelium, the immobility of the ICU stay and the exaggerated coagulation process, increases the probability of thrombosis.
“The patient who has varicose veins and who catches covid therefore has an additional risk of having this vascular complication”, concludes Rossi.
The good news is that there are ways to prevent, diagnose, and treat these thrombotic events.
The medical counterattack
One of the first attitudes of specialists when confronted with a more serious case of covid is to prescribe anticoagulant drugs.
“It should be clarified here that these drugs are reserved for hospitals, applied by infusions or injections, and are not indicated for all infected people,” says Negri.
“And even when that patient who was more critical comes out, they may need to continue using oral anticoagulants for a while,” adds the doctor.
The purpose of this preventive treatment is to “hold the reins” of the coagulation process and prevent the appearance of thrombi that clog the vessels.
When this strategy is not enough, it is important to know the most common symptoms of this problem.
“The signs depend a lot on the area affected. If it is the brain, the individual may have changes in mobility, difficulty speaking, or not being able to move a part of the body. Now if the problem is concentrated in the lungs it will feel short of breath and throbbing, if it appears on the legs it can cause swelling and warmth,” Jardim describes.
However, more than memorizing a list of symptoms, it is recommended that you promptly report any discomfort you feel to the healthcare professional following the case, especially if you have varicose veins or know that close family members have had them. thrombosis in the past.
“It should also be noted that the condition of the patient, around the sixth or seventh day from the start of the covid symptomsstarts to get worse and has body aches, fever, fatigue, shortness of breath…”, underlines Negri.
“In this situation, it may be necessary to check that there is no risk of thrombosis.”
From the initial suspicion, a series of blood and imaging tests (such as ultrasound and CT scan) can be used to make the correct diagnosis.
Also in this area, another essential requirement is agility: if the thrombus obstructs a larger vein or artery, the sooner it is detected and treated, the better the prognosis.
“Prompt care makes all the difference. Some tissues in our body, such as the brain and heart, last a short time if they are deprived of blood,” says Jardim.
If the test reports even identify thrombosis, the next step is to prescribe certain drugs from the class of anticoagulants, which prevent the appearance of new clots, and thrombolytics, which help dissolve the already installed thrombus.
In some cases, it is necessary to resort to surgical interventions that unclog the clogged vessel using catheters and other equipment.
Finally, we must not forget the attitudes that reduce the probability of occurrence of thrombosis.
In the specific case of covid, the first step is to avoid contact with the virus as much as possible. For this, the indication is to take the recommended doses of vaccine, to wash your hands often and to wear good quality masks in closed environments or in built-up areas.
“Overall, the recommendation is to have a healthy life,” summarizes Jardim.
The InCor pulmonologist explains that a routine of physical exercise is essential so that the veins and arteries do not suffer from sudden blockages of blood flow.
“And you don’t necessarily have to go to the gym. Having a more active routine already greatly reduces the risk of having inadequate or inappropriate clotting.”