Throm-PED registry: Thrombosis of the hepatic vessels incl. Portal Vein thrombosis and Hepatic vein thrombosis with or without underlying liver disease

May 26, 2024


The first DOACs have been approved for treatment of thromboembolism in children. Based on the risk benefit profiles published so far, we expect DOACs to be widely used in children. The strict inclusion criteria for participation in the RCTs limit their generalizability, particularly to those with serious medical conditions that account for a significant proportion of pediatric VTE patients in clinical practice. Systematic exclusion of children with elevated liver enzymes or liver disease from clinical trials forming the basis for DOAC regulatory approvals, leaves a critical gap regarding the safety of DOAC application in children with liver disease.

Given, that children with chronic liver disease are both at higher risk for thrombotic events and bleeding, there exists a pressing medical need to improve anticoagulation for this patient group.

It is essential to evaluate the safety and effectiveness of DOAC in this patient group as chronic liver disease is associated with substantial alterations in the coagulation system as well as drug metabolism. This is specifically pertinent as all DOACs depend to varying degree, on liver metabolism for excretion. Hence, liver disease raises concerns for drug accumulation and toxicity. Whether there is a role for measuring drug levels or levels of anticoagulation (e.g. anti-Xa or dilute thrombin time) to monitor specific subgroups of children remains an important question.

However, there is in general limited data on the treatment of thrombosis of hepatic vessels in children (incl. portal vein thrombosis and hepatic vein thrombosis), including also the use of LMWH, Warfarin and invasive vascular procedures such as thrombectomy, thrombolysis, TIPS, Meso-Rex Shunts, other shunts (spleno-renal, meso-caval) etc.

We plan to utilize the existing Throm-Ped Registry and to collect additional data on children with thrombosis of the hepatic and portal vein.

Project recruiting


To study efficacy and safety of different treatment strategies in pediatric patients <18 years with thrombosis of hepatic vessels. To expand the knowledge on treatment strategies and outcomes across different risk profiles and comorbidities in this particular patient population.



1)           To describe current practices in the use of anticoagulants, incl DOACs (apixaban, dabigatran, edoxaban and rivaroxaban), LMWH, Warfarin and invasive procedures incl thrombectomy, local thrombolysis, TIPS, Meso-Rex shunts, other shunts in pediatric patients with hepatic and/or portal vein thrombosis.


2) To obtain efficacy and safety data on real-world use of DOACs, LMWH, Warfarin and invasive procedures in pediatric patients with hepatic and/or portal vein thrombosis, including:

  1. Determine the rate of thrombus resolution, reduction in size or progression while on anticoagulant treatment or after invasive procedures as measured by imaging techniques (i.e. ultrasound, CT scan).
  2. Evaluate vessel recanalization and resolution of symptoms associated with hepatic and portal vein thrombosis.
  3. Rate and risk factors associated with (i) major or (ii) clinically relevant non-major bleeding associated with concomitant therapies, as defined by ISTH criteria.
  4. Monitor liver function, especially for patients with underlying liver disease.
  5. Development of portal hypertension.
  6. Mortality within the first 12 months of therapy.
  7. Recurrence of thrombosis during follow-up.

3)           LMWH/DOAC drug levels, anti X a levels during LMWH/DOAC treatment.

4)           Patients with thrombosis of the hepatic vessels not receiving treatment will serve as controls.

Main study parameters/endpoints:

1)           Patient characteristics including age, gender, ethnicity, TE type, location, number and types of risk factors, underlying medical conditions, concomitant medications.

2)           Liver function, scoring systems PELD/MELD.

3)           Platelet numbers, liver enzymes, parameters of plasma coagulation (fibrinogen, aPTT, PT/INR), d-dimer, antithrombin), albumin.

4)           Rates of bleeding (major, clinically relevant non-major including menorrhagia).

5)           Rate of recurrent TE.

6)           Rate of recanalization, thrombosis progression.

7)           Long term consequences: Development of portal hypertension or other clinical events.


Nature and extent of the burden and risks associated with participation, benefit and group relatedness: This is an observational study without any additional blood samples, questionnaires, site visits etc. so the burden is minimal for the included patients. Data will be de-identified in the RedCap database.


Study file(s)


Maria Magnusson

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