Catheter-related thrombosis could impair blood flow in the vein, block the central venous catheter, induce catheter-related infection or venous thromboembolism in the deep veins or pulmonary vessels, which furthermore progress into the post-thrombotic syndrome.

Researches using echogenic mass as the primary outcome could miss those premature thrombi which might not be seen on traditional ultrasonography but may be detected by Duplex and Doppler ultrasound with vessel compression. Moreover, studies indicated that some thrombus developed after the catheter removal. Removal of the catheter is not the endpoint of thrombus detection. This study is designed to determine the preventive effects of continuous heparin infusion on real-world central venous catheter-related thrombosis in infants after cardiac surgery.

Catheter-related thrombosis could impair blood flow in the vein, block the central venous catheter, induce catheter-related infection or venous thromboembolism in the deep veins or pulmonary vessels, which furthermore progress into the post-thrombotic syndrome. Researches using echogenic mass as the primary outcome could miss those premature thrombi which might not be seen on traditional ultrasonography but may be detected by Duplex and Doppler ultrasound with vessel compression. Moreover, studies indicated that some thrombus developed after the catheter removal. Removal of the catheter is not the endpoint of thrombus detection. This study is designed to determine the preventive effects of continuous heparin infusion on real-world central venous catheter-related thrombosis in infants after cardiac surgery. One hundred and twenty-four infants were randomized to the intervention group or the control group. Unfractionated heparin or normal saline was infused continuously through each lumen of the central venous catheter at the speed of 0.5 ml/h/line until the catheter was removed. Catheter-related thrombosis was detected by point-of-care Duplex and Doppler ultrasound periodically until 30 days after the cardiac surgery or discharge, whichever comes first.

Inclusion Criteria:

• less than 3 months of age at admission, post-cardiac surgery, with CVC indwelled

Exclusion Criteria:

• parents' refusal, requiring postoperative anticoagulant administration (extracorporeal membrane oxygenation support, prosthetic devices), the contradiction to heparin (coagulopathy or hypercoagulable state, platelet level less than 50000/dL, clinically significant bleeding tendency, allergy to heparin)

All data published and other related data were available after publication. No private information would be published.

From the date of publication to 5 years after publication.

Requests to the corresponding author were necessary.

Infant participants were blinded naturally, while ultrasonographers for central venous catheter (CVC)-related thrombosis were blinded, especially after interventions were stopped.