The Center for Thromboembolic Diseases (CDT), located in the Hemostasis Laboratory of the Unicamp Hemocenter, has begun unprecedented epidemiological research in Brazil on venous thrombosis – a disease characterized by the formation of a thrombus (clot) in a blood vessel that interrupts or hinders the normal flow of venous blood.
The CDT (Center for Diagnostic and Therapeutic Research) began epidemiologically registering the disease in three patient groups: adults with thrombosis in their arms or legs, adult cancer patients, and hospitalized children. According to Professor Joyce Maria Annichino of the Faculty of Medical Sciences (FCM) at Unicamp, coordinator of the CDT, the country currently lacks detailed information on the prevalence of the disease and its complications. “If you look for Brazilian data on the occurrence of post-thrombotic syndrome in patients with thrombosis in the leg, you won't find it,” she states. “How many of the patients who had thrombosis had a new episode within a two-year period? We don't have that data. In Brazil, what percentage of cancer patients have thrombosis? Nobody knows,” argues the professor.
"We will therefore present unprecedented data to the country, which can assist in decision-making and provide support for the establishment of public health policies," added Annichino.
The research, which is already underway, has established a network of researchers, doctors, and other health professionals working in 11 SUS (Brazilian public healthcare system) hospitals across six cities in São Paulo state: Campinas, São Paulo, Ribeirão Preto, São José do Rio Preto, Barretos, and Botucatu.
The collected demographic and clinical data are entered into the REDCap platform (Research Electronic Data Capture). Blood samples are collected and stored in the Biobank of the Unicamp Hemocenter.
The goal is to build a database with five thousand cases of adults with cancer, who will be monitored for one year, recording the occurrence of thrombosis or death.
The second registry includes patients with acute venous thrombosis in the arms or legs. The research will follow them for two years, evaluating the occurrence of post-thrombotic syndrome or recurrence.
The third area of focus relates to children who received a venous catheter during hospitalization. Researchers are evaluating the occurrence of venous thrombosis in these interventions and the progression of the condition.
The inclusion of children has already been completed, with the diagnosis of almost 250 thromboses out of a total of more than a thousand cases. These patients are being monitored for six months after hospital discharge.
The research is supported by the São Paulo Research Foundation (FAPESP) and the Research Dean's Office of Unicamp.
According to the International Society on Thrombosis and Haemostasis (ISTH), approximately 10 million cases of venous thrombosis are recorded worldwide each year, an incidence of 1 to 2 cases per thousand individuals annually. Of these, about 100 cases result in death.
In Brazil, according to the Ministry of Health, in the first six months of 2025, more than 36 new diagnoses were recorded, an average of 200 hospitalizations per day. According to Annichino, this is below what is expected for the country, which can be partially explained by the fact that it is not a disease subject to mandatory reporting.
Annichino reinforces the need for a massive awareness campaign about prevention methods (see box below).
The professor highlights a major event: the enactment of Law 15.448/2026, which spent three years in process and was approved thanks to the efforts of the CDT and the Brazilian Society of Thrombosis and Hemostasis, of which she is president. According to this law, all hospitals or healthcare services that offer inpatient care will have 180 days to create a commission with permanent thrombosis prevention programs. With this, any hospitalized patient will undergo a thrombosis risk assessment that will guide the adoption of prophylactic measures, such as the use of anticoagulant medications. "This is a milestone in our country, as many cases of thrombosis can be avoided," she celebrates.
Spokesperson
About a year ago, the CDT launched the character Maria Clot, who has since been bringing information about thrombosis to the public, especially children. “Maria Clot is our link to the population. The university plays a major role in generating knowledge, but this knowledge needs to be disseminated in a clear and simple way, and that's why the character was created,” says Annichino.
Maria Clot is a reporter who brings scientific knowledge about thrombosis to the general public through social media, in-person events, and programs on Educa TV, a channel affiliated with the Campinas city government.
Clot is her childhood nickname, given to her by her mother, a doctor. In English, the term means "clot," that is, a clump of blood. The nickname arose because Maria is a very gregarious person, always bringing everyone around her together. In her adolescence, she had thrombosis due to the use of contraceptives, making the nickname even more meaningful.
In recent months, Clot has gained a family – with a father, mother, and brother. The character has also gained a boyfriend, named Bled (an English word associated with bleeding), and a dog, Trombito.
The professor says that from the beginning the idea was to create a kind of series, in which issues related to thrombosis would be addressed in a natural way. The format was adapted and, with the help of artificial intelligence, two episodes are now produced weekly, published on the Center's social media, on the mariaclot.cdt Instagram profile and also on TikTok.
How to prevent thrombosis
- Practice physical activities: Exercising three to four times a week (practicing walking and strength training, for example) is essential.
- Avoid a sedentary lifestyle: Get up and walk around for a few minutes every hour if you work sitting down. On long trips (by plane or car), take breaks to stretch your legs, walk down the aisle, or do some ankle movements.
- Stay hydrated: Drinking plenty of water throughout the day keeps the blood more fluid, making it harder for clots to form.
- Quit smoking: Cigarettes inflame blood vessels, damage the inner walls of veins, and impair blood flow.
- Control your weight: Obesity increases pressure in the veins of the legs and makes it difficult for blood to return.
- Pay attention to hormones: Medications such as birth control pills and hormone replacement therapies can thicken the blood and increase the risk, always requiring medical advice.
- Use of compression stockings: They may be recommended by a doctor to improve venous return, especially during long trips or periods of rest.
- Drug prophylaxis: In very high-risk situations, such as hospitalizations, surgeries, or prolonged bed rest, the use of anticoagulant medications under medical prescription is vital.
Source: Brazilian Society of Thrombosis and Hemostasis (SBTH)
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Unicamp Blood Center will make an unprecedented record of venous thrombosis in Brazil
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