NCT05735639

Brief Summary

Endovenous interventions are keyhole operations for varicose veins that are carried out from within the vein itself. Varicose veins are enlarged veins close to the surface of the skin. They are connected to the bigger deeper veins in the leg (known as deep veins). Because of this, operations to close the varicose veins can increase the chance of a blood clot forming in the deep veins. Blood clots in the deep veins happen in around 1 in 50 people after endovenous operations. A clot in the leg can cause swelling, pain, and other long-term problems. If a clot in the leg breaks off and travels to the lungs, it can cause problems with the lung' ability to move oxygen from the air into the blood and may, in rare cases, be life threatening. Varicose vein procedures may carry a slightly higher risk of blood clot formation, and we are currently unsure if current clot reducing medicines are beneficial in preventing blood clots in people having varicose vein procedures. This study will investigate if it is worthwhile prescribing medicines to reduce blood clots after varicose vein procedures.

Trial Health

77
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
6,660

participants targeted

Target at P75+ for phase_4

Timeline
20mo left

Started Jan 2024

Longer than P75 for phase_4

Geographic Reach
1 country

1 active site

Status
recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Progress58%
Jan 2024Dec 2027

First Submitted

Initial submission to the registry

January 19, 2023

Completed
1 month until next milestone

First Posted

Study publicly available on registry

February 21, 2023

Completed
11 months until next milestone

Study Start

First participant enrolled

January 22, 2024

Completed
3.4 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

June 30, 2027

Expected
6 months until next milestone

Study Completion

Last participant's last visit for all outcomes

December 31, 2027

Last Updated

April 24, 2026

Status Verified

April 1, 2026

Enrollment Period

3.4 years

First QC Date

January 19, 2023

Last Update Submit

April 21, 2026

Conditions

Outcome Measures

Primary Outcomes (1)

  • Imaging confirmed lower limb deep vein thrombosis (DVT) with or without symptoms, or pulmonary embolism (PE) with symptoms within 90 days of varicose vein treatment.

    The rate of lower limb DVT with or without symptoms, or PE with symptoms within 90 days of varicose vein treatment.

    90 days

Secondary Outcomes (8)

  • Lower limb DVT without symptoms

    21 - 28 days

  • Lower limb DVT with symptoms

    90 days

  • PE with symptoms

    90 days

  • Comparisons of quality of life at 7- and 90-days post-procedure

    90-days

  • Cost-effectiveness of providing pharmacological thromboprophylaxis

    90 days

  • +3 more secondary outcomes

Study Arms (3)

Compression therapy alone

NO INTERVENTION

Compression therapy + single dose of low-molecular weight heparin at time of procedure

EXPERIMENTAL

A single prophylactic dose of low molecular weight heparin (LMWH) (e.g., dalteparin sodium, tinzaparin sodium, enoxaparin sodium) will be prescribed as per standard practice and administered in accordance with the relevant Summary of Product Characteristics (SmPC), manufacturer's recommendations and instructions for use.

Drug: Dalteparin SodiumDrug: Tinzaparin SodiumDrug: Enoxaparin Sodium

Compression therapy + single dose of LMWH at time of procedure + extended course of LMWH or DOAC

EXPERIMENTAL

An extended duration of LMWH (e.g., dalteparin sodium, tinzaparin sodium, enoxaparin sodium) or an extended duration of a direct oral anticoagulant (DOAC) (e.g., rivaroxaban, apixaban, dabigatran etexilate) will be prescribed as per current local practice and administered in accordance with the relevant SmPC, manufacturer's recommendations and instructions for use. The duration of this must be at least 7 days, but can be in line with local practice i.e., 7, 10 or 14 days.

Drug: Dalteparin SodiumDrug: Tinzaparin SodiumDrug: Enoxaparin SodiumDrug: RivaroxabanDrug: ApixabanDrug: Dabigatran Etexilate

Interventions

Low molecular weight heparin

Compression therapy + single dose of LMWH at time of procedure + extended course of LMWH or DOACCompression therapy + single dose of low-molecular weight heparin at time of procedure

Low molecular weight heparin

Compression therapy + single dose of LMWH at time of procedure + extended course of LMWH or DOACCompression therapy + single dose of low-molecular weight heparin at time of procedure

Low molecular weight heparin

Compression therapy + single dose of LMWH at time of procedure + extended course of LMWH or DOACCompression therapy + single dose of low-molecular weight heparin at time of procedure

Direct oral anticoagulant

Compression therapy + single dose of LMWH at time of procedure + extended course of LMWH or DOAC

Direct oral anticoagulant

Compression therapy + single dose of LMWH at time of procedure + extended course of LMWH or DOAC

Direct oral anticoagulant

Compression therapy + single dose of LMWH at time of procedure + extended course of LMWH or DOAC

Eligibility Criteria

Age18 Years+
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Adults (\>18 years)
  • Scheduled to undergo endovenous intervention of truncal varicose veins under local anaesthesia
  • Treatment technologies including radiofrequency, laser, mechanochemical, foam sclerotherapy and cyanoacrylate glue

You may not qualify if:

  • Clinical indication for therapeutic anticoagulation e.g., atrial fibrillation
  • Previous personal or first-degree relative history of VTE
  • Thrombophilia
  • Female patients of childbearing potential who have a positive pregnancy test
  • A history of allergy to heparins or direct oral anticoagulants
  • A history of heparin-induced thrombocytopenia
  • Inherited and acquired bleeding disorders
  • Evidence of active bleeding
  • Concomitant major health problems such as active cancer and chronic renal and/or liver impairment
  • Known thrombocytopenia (platelets known to be less than 50 x 109
  • /l)
  • Surgery or major trauma in the previous 90 days
  • Recent ischemic stroke in the previous 90 days
  • Inability to provide consent

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Imperial College Hospital NHS Foundation Trust

London, W6 8RF, United Kingdom

RECRUITING

MeSH Terms

Conditions

Venous ThromboembolismVaricose Veins

Interventions

DalteparinTinzaparinenoxaparin sodiumRivaroxabanapixabanDabigatran

Condition Hierarchy (Ancestors)

ThromboembolismEmbolism and ThrombosisVascular DiseasesCardiovascular Diseases

Intervention Hierarchy (Ancestors)

Heparin, Low-Molecular-WeightHeparinGlycosaminoglycansPolysaccharidesCarbohydratesThiophenesSulfur CompoundsOrganic ChemicalsMorpholinesOxazinesHeterocyclic Compounds, 1-RingHeterocyclic CompoundsPyridinesBenzimidazolesHeterocyclic Compounds, 2-RingHeterocyclic Compounds, Fused-Ring

Central Study Contacts

Study Design

Study Type
interventional
Phase
phase 4
Allocation
RANDOMIZED
Masking
SINGLE
Who Masked
OUTCOMES ASSESSOR
Purpose
PREVENTION
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

January 19, 2023

First Posted

February 21, 2023

Study Start

January 22, 2024

Primary Completion (Estimated)

June 30, 2027

Study Completion (Estimated)

December 31, 2027

Last Updated

April 24, 2026

Record last verified: 2026-04

Data Sharing

IPD Sharing
Will not share

Locations