Chronic IVC Occlusion Predisposing to Acute Lower Extremity DVT in Children

Congenital atresia of the inferior vena cava (IVC) is a known risk factor for spontaneous lower extremity thrombosis in adults. However, little is known about the incidence of IVC occlusion and its relationship to spontaneous lower extremity thrombosis in children. We reviewed the medical records of consecutive patients with IVC occlusion and lower extremity DVT who presented to our institution between 2008 and 2015. Data were reviewed for risk factors for thrombosis, treatment, and outcomes including recurrent thrombosis, bleeding complications, and post-thrombotic syndrome. This represents the largest reported analysis of previously healthy pediatric patients with occult chronic IVC occlusion presenting with unprovoked acute lower extremity thrombosis. Ten patients aged 13 to 18 years (median age 16.5yrs, 90% male) presenting with acute lower extremity thrombosis were found to have chronic occlusion of the IVC. One patient presented with pulmonary embolism. Seven patients underwent site-directed thrombolysis, and 3 patients received anticoagulation alone. All patients had persistent IVC occlusion regardless of treatment. Two patients had recurrent thrombosis while on anticoagulation. There were no provoking factors identified that preceded the presentation of acute lower extremity thrombosis, and none had predisposing risk factors that could explain the IVC occlusion. Four patients had a negative thrombophilia work up. Five had mild thrombotic risk factors such as heterozygosity for Factor V Leiden or elevated factor VIII levels. Only one patient had a significant thrombophilic risk factor, familial mild protein C deficiency. Five patients had post thrombotic syndrome based on standardized scoring tools. All patients remain on indefinite anticoagulation. This case series suggests that chronic IVC occlusion increases the risk of unprovoked lower extremity thrombosis and pulmonary embolism in healthy children with resultant long-term complications. It also highlights the importance of imaging the IVC in young patients with unprovoked or minimally provoked iliofemoral DVT. Indefinite anticoagulation in patients presenting with unprovoked thrombosis secondary to IVC occlusion should be considered.