Children survive blood clots, but are we failing them afterward?
Recent medical advances allow us to effectively care for more children with medically complex conditions, including premature newborns and children with acute and chronic illnesses. One unfortunate complication of administering life-saving therapies is venous thrombosis, or blood clot, at the site where clinicians administer life-saving medications and nutrition.
The rate of blood clots in hospitalized children has been steadily increasing. Although the 2024 American Society of Hematology (ASH)/International Society of Thrombosis & Hemostasis (ISTH) guidelines have helped clinicians improve the diagnosis and treatment of thromboembolism in pediatric patients, our long-term care (after treatment of the blood clot) has not been as consistent.
After developing a blood clot, patients are at risk of developing post-thrombotic syndrome (PTS), a long-term complication that can cause swelling, pain and fatigue in the affected extremity. Non-extremity blood clots, like those in the lungs or liver, also can cause long-term dysfunction of the associated organ.
As members of the Scientific and Standardization Subcommittee on Pediatric and Neonatal Thrombosis and Hemostasis of ISTH, we recently published guidance for the clinical care of children with extremity thrombosis who are at risk of PTS. We followed up on this guidance with a cross-sectional international survey to gain insight into global long-term care for children with a history of venous thrombosis, known as the Assessment of Screening and Treatment Of thrombosis complications in pediatrics (ASTRO-Kids).
A total of 128 participants from 91 centers worldwide completed the survey. Our survey results demonstrate that long-term care for children with thrombosis is inconsistent and likely inadequate, as less than 35% of respondents follow children with extremity or non-extremity blood clots for longer than two years to assess for long-term complications. Long-term follow-up of neonates was even less than that of children over 12 months of age, despite prior evidence demonstrating that PTS in neonates can present up to 10 years following the venous blood clot.
The results of the ASTRO-Kids survey demonstrate that we have a lot of work to do to ensure that children with a history of venous blood clots have access to the long-term evaluation and care that they need for PTS. This starts with increasing awareness across the community of pediatric clinicians that PTS can occur in up to 25% of those with extremity thrombosis and may develop years after the blood clot was diagnosed and treated. Targeted CME programs should be developed for clinicians who care for children long-term with a history of venous thrombosis. Patients and their families should be educated at the end of the anticoagulation treatment period about the signs and symptoms of PTS to watch for long-term. The development of impactful, visually appealing, parent-friendly materials would go a long way in driving home this message.
As PTS can be challenging to treat, emphasis must also be placed on timely diagnoses of venous blood clots and aggressive upfront therapy with anticoagulation to limit the potential long-term complications. Funding for quality improvement collaboratives within pediatric intensive care and acute inpatient units may support the development of workflow algorithms to quickly identify children at-risk of acute venous thrombosis and to initiate anticoagulation promptly. Additionally, funding for prospective clinical trials is needed to identify prognostic clinical and laboratory risk factors that place children with venous thrombosis at greatest risk of developing PTS.
Through coordinated efforts in early detection, evidence‑based treatment, and sustained research investment, we can meaningfully reduce the burden of PTS for children affected by venous thrombosis.
By Dr. Clay Cohen, associate professor of pediatrics at Baylor College of Medicine, associate chief, pediatric hematology, and director, Hemophilia Treatment Center, Texas Children’s Cancer and Hematology Center
