Nonextremity thrombosis sequelae in children: screening, diagnosis, and management

Nonextremity thromboses constitute approximately 40% of pediatric venous thromboembolism and are associated with significant organ-specific morbidity. These events may lead to chronic complications such as postpulmonary embolism syndrome after pulmonary embolism, neurocognitive impairment following cerebral sinus venous thrombosis, portal hypertension after portal vein thrombosis, and hypertension or chronic kidney disease following renal vein thrombosis. Despite their clinical relevance, the epidemiology, natural history, and optimal management of these sequelae remain incompletely defined in children, and existing recommendations, where available, rely largely on expert opinion or extrapolation from adult studies. Long-term follow-up practices are inconsistent, contributing to under recognition of chronic morbidity. In this JTH in Clinic review, we present 4 representative cases illustrating the spectrum of postthrombotic sequelae arising from commonly encountered nonextremity thrombotic events in children. For each scenario, we summarize epidemiology, pathophysiology, and management considerations, highlighting areas where pediatric-specific data are limited. This case-based approach aims to provide clinicians with our collective approach for recognizing, assessing, and managing long-term complications of nonextremity thrombosis. By emphasizing systematic surveillance and multidisciplinary follow-up, we aimed to promote earlier identification and more consistent management of long-term sequelae in children with nonextremity VTE.