A team of researchers analyzed a national management guideline for catheter-related venous thrombosis (CVT) that had been implemented in neonatal intensive care units (NICUs) in the Netherlands in 2014. Findings were presented at the International Society on Thrombosis and Haemostasis (ISTH) 2021 Congress by C. Heleen van Ommen, PhD, of the Erasmus Medical Center Sophia Children’s Hospital in Rotterdam, The Netherlands, and colleagues.

The findings presented by Dr van Ommen and colleagues were results from the NEOCLOT study. This was a prospective, observational cohort study that took place across 10 Dutch NICUs at which neonates with CVT were admitted during the years of 2014 through 2019. Patients were managed according to whether CVT occurred in a vein or in the right atrium. The management protocol for venous CVT was based on whether occlusion was present, while CVT in the right atrium was treated according to risk status or volume of the right atrium that was affected.

Possible treatments included a wait-and-see approach, anticoagulation, or recombinant tissue plasminogen activator (r-TPA), alone or in combination. The primary study outcomes were death from CVT, recurrent thrombosis, or major bleeding, while secondary outcomes included clinically relevant bleeding and end-of-treatment thrombotic burden.

Continue Reading

There were 116 neonates evaluated in this study, of whom 92 were delivered preterm. The median gestational age was 28 weeks and 4 days, with neonates having a median birthweight of 1092 grams (range, 425-5384). Three-quarters (75%) of the neonates had symptoms, such as thrombocytopenia in 43%, persistent infection in 26%, and swollen leg/arm in 24%.

Thrombosis occurred in a vein in 72 cases, compared with 44 in the right atrium. Slightly over half, or 39, of the venous cases involved occlusion, which was treated with anticoagulation alone in 27 cases. Most nonocclusive venous cases received a wait-and see approach. Most right atrial cases, or 35 cases, involved less than half of the right atrium and were treated with a wait-and-see approach in 23 cases, while others were treated with anticoagulation, r-TPA, wait-and-see, or combinations of these. A total of 9 right atrial cases were considered high risk, and no cases involved half or more of the right atrium.

Identified risk factors included suspected infection in 60% of neonates, surgery in 12%, and shock in 11%. There was a death due to pulmonary embolism in 1 patient. Another 3 patients (2.6%) experienced recurrent thrombosis, while 9 patients (7.8%) had major bleeding. Two of these patients were on thrombolysis, and 7 were receiving low-molecular-weight heparin; 5 of these 7 patients experienced subcutaneous catheter-related major bleeding in a leg. Gastrointestinal bleeding that was clinically relevant occurred in 1 patient.

Following treatment, findings on repeat ultrasonography with a median of 49 days were reported as normalized in 47% of neonates, improved in 36%, unchanged in 8%, or unknown in 9%.

The researchers concluded that the NEOCLOT protocol appeared to be safe and effective if not involving a subcutaneous catheter to deliver low-molecular-weight heparin.


Van Ommen CH, Bergman KA, Boerma M, et al; NEOCLOT Study Group. NEOCLOT: management of catheter-related venous thrombosis in preterm and term neonates. Paper presented at: International Society on Thrombosis and Haemostasis (ISTH) 2021 Congress; July 17-21, 2021; virtual. Abstract OC 20.1.