Comparison Of Different Mechanical Thrombectomy Devices in Endovascular Treatment of Acute Iliofemoral Venous Thrombosis

May 26, 2026 updated by: RenJi Hospital

Comparison Of Different Mechanical Thrombectomy Devices in Endovascular Treatment of Acute Iliofemoral Venous Thrombosis (The COMET Study)

A head-to-head comparison of two different types of percutaneous mechanical thrombectomy (PMT) - ClotTriever System versus aspiration thrombectomy (including rheolytic thrombectomy) - in patients with acute iliofemoral deep vein thrombosis (DVT) was conducted to determine whether ClotTriever System can improve thrombus clearance rate, reduce the incidence of post-thrombotic syndrome (PTS), and enhance the long-term efficacy of endovascular treatment for acute iliofemoral DVT.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Acute deep venous thrombosis (DVT) is associated with development of post-thrombotic syndrome (PTS). Early removal of iliofemoral thrombosis by percutaneous mechanical thrombectomy (PMT) may reduce the incidence of PTS. There is currently a lack of research on which device is optimal for thrombus removal. The aim of this study is to conduct a multicenter, observational, prospective cohort study in patients with acute iliofemoral deep vein thrombosis (DVT), performing a head-to-head comparison of two different types of mechanical thrombectomy devices - ClotTriever System versus aspiration thrombectomy (including rheolytic thrombectomy) - to determine whether ClotTriever System can improve thrombus clearance rate, reduce the incidence of post-thrombotic syndrome (PTS), and enhance the long-term efficacy of endovascular treatment for acute iliofemoral DVT.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
180

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • China
      • Shanghai, China
        • Recruiting
        • Renji hospital
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

180

Description

Inclusion Criteria:

  1. Aged between 18 and 85 years;
  2. Diagnosed with acute iliofemoral venous thrombosis, with thrombosis involving at least the iliac vein and common femoral vein;
  3. Time from symptom onset to endovascular treatment ≤ 14 days;
  4. Patients undergo endovascular treatment with percutaneous mechanical thrombectomy;
  5. Patients sign the informed consent form.

Exclusion Criteria:

  1. Presence of PTS in the limb to be treated in this procedure, or a history of symptomatic DVT in the same limb within the past 2 years;
  2. Concurrent symptomatic acute DVT involving the iliac vein and/or common femoral vein in the contralateral limb;
  3. Known allergy to heparin, low molecular weight heparin, contrast agents, etc.
  4. Concomitant severe pulmonary embolism with hemodynamic changes, such as hypoxia, hypotension, etc.
  5. Inability to tolerate endovascular treatment due to conditions such as acute systemic illness, severe dyspnea, etc.
  6. Concomitant severe renal insufficiency with creatinine clearance < 30 ml/min;
  7. Concomitant active bleeding, severe hepatic insufficiency, bleeding tendency, etc.
  8. Concomitant severe anemia (hemoglobin < 8.0 mg/dL) or platelet count < 80,000/mL;
  9. History of subarachnoid hemorrhage, intracranial hemorrhage, intracranial vascular malformation, or intracranial aneurysm;
  10. Pregnant women;
  11. Presence of other diseases (e.g., advanced malignancy, cardiac insufficiency, etc.) with an expected life expectancy < 24 months
  12. Participation in any drug or medical device clinical trial that may interfere with this study within the past 1 month;
  13. Patients unwilling to participate in this trial.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
ClotTriever System group
Patients receive percutaneous mechanical thrombectomy by ClotTriever System
Procedure: Percutaneous mechanical thrombectomy by ClotTriever System
The procedure is performed via the ipsilateral popliteal vein access or the ipsilateral femoral vein access. After puncture under fluoroscopic or ultrasound guidance, a vascular sheath is inserted, systemic heparinization is administered, and a guidewire is advanced antegradely into the inferior vena cava with the assistance of a catheter to establish the access. Once the access is established, treatment is carried out using stent retriever devices. Available stent retriever devices include currently marketed options such as ClotTriever (INARI MEDICAL, USA). After thrombectomy, the thrombus removal efficacy is assessed by venography.
Aspiration thrombectomy group
Patients receive percutaneous mechanical thrombectomy by aspiration or rheolytic thrombectomy
Procedure: Percutaneous mechanical thrombectomy by aspiration or rheolytic thrombectomy
The procedure is performed via the ipsilateral calf deep vein access, the ipsilateral popliteal vein access, or the ipsilateral femoral vein access. After puncture under fluoroscopic or ultrasound guidance, a vascular sheath is inserted, systemic heparinization is administered, and a guidewire is advanced antegradely into the inferior vena cava with the assistance of a catheter to establish the access. Once the access is established, treatment is carried out using mechanical aspiration thrombectomy devices. Available aspiration thrombectomy devices include currently marketed options such as the AngioJet thrombectomy catheter (Boston Scientific, USA) and the Acostream thrombectomy catheter (Acotec, China). After thrombectomy, the thrombus removal efficacy is assessed by venography.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Incidence of PTS
Time Frame: At 24 months
Assessed by the Villalta score
At 24 months

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Incidence of moderate-to-severe PTS
Time Frame: at 6, 12, and 24 months
Assessed by the Villalta score
at 6, 12, and 24 months
Clinical classification of Clinical-Etiology-Anatomy-Pathophysiology (CEAP)
Time Frame: at 6, 12, and 24 months
Based on clinical symptoms
at 6, 12, and 24 months
Patency rate of the ipsilateral iliofemoral vein
Time Frame: at 12 months and 24 months
Assessed by color Doppler ultrasound
at 12 months and 24 months
Incidence of PTS
Time Frame: Assessed by the Villalta score
at 6 and 12 months
Assessed by the Villalta score
Recurrence rate of symptomatic Deep Vein Thrombosis (DVT)
Time Frame: at 24 months
Assessed by symptoms combined with ultrasound examination in the ipsilateral limb
at 24 months
Rate of re-intervention
Time Frame: at 24 months
Assessed by documentation of clinical reintervention
at 24 months
Quality of life score
Time Frame: at 6, 12, and 24 months
Assessed by Venous Insufficiency Epidemiological and Economic Study Quality of Life questionnaire (VEINES-QOL)
at 6, 12, and 24 months

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Incidence of major bleeding
Time Frame: at 24 months
Defined by International Society on Thrombosis and Haemostasis (ISTH) criteria
at 24 months
Incidence of symptomatic Pulmonary Embolism (PE)
Time Frame: at 24 months
Assessed by symptoms combined with contrast-enhanced computed tomography examination
at 24 months
Incidence of symptomatic Venous Thromboembolism (VTE)
Time Frame: at 24 months
Assessed by symptoms combined with ultrasound and contrast-enhanced computed tomography examination
at 24 months
All-cause mortality
Time Frame: at 24 months
All-cause death
at 24 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
RenJi Hospital

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Changhai Hospital
First People's Hospital of Hangzhou
West China Hospital
Chengdu University of Traditional Chinese Medicine
Shanghai Ninth People's Hospital Affiliated to Shanghai Jiao Tong University
Wenzhou Central Hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 1, 2024

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 31, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 31, 2028

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
May 26, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 26, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 3, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
June 3, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 26, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • The COMET Study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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