Catheter-related thrombosis in children with cancer

Objective: The prevalence of asymptomatic catheter-related thrombosis of th e upper venous system in children with cancer has not been determined. We e valuated patients with cancer and implantable central venous catheters (por ts) for this complication. Study design: Children with cancer undergoing port removal were eligible fo r this study. Vessel patency was evaluated by contrast venography. We exami ned each child for physical stigmata of thrombosis and retrospectively asse ssed catheter-related mechanical difficulties and infections. Results: Thirty-one ports had been placed in 24 children (aged 20 months to 18 years; median age, 9 years) with diagnoses of leukemia/lymphoma (n = 10 ), solid tumor (n = 12), and histiocytosis (n = 2). Venography showed abnor malities in 12 of the 24 patients. Physical examination revealed dilated su perficial veins on the chest in 3 patients. Venograms showed abnormalities in all 3 children with prominent superficial thoracic veins. Nine of the 21 other patients had clinically occult central venous occlusion. Conclusion: Fifty percent (95% CI, 30% to 70%) of children who had implanta ble ports removed during or after treatment of cancer exhibited deep venous thrombosis at the site of catheter placement. Future studies should determ ine the contribution of inherited and other acquired risk factors for throm bosis and assess measures to prevent and/or treat catheter-related thrombos is in this population.