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

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: Recruiting
• Conditions: Deep Vein Thrombosis
• Intervention / Treatment: Procedure: Percutaneous mechanical thrombectomy by ClotTriever System; Procedure: Percutaneous mechanical thrombectomy by aspiration or rheolytic thrombectomy

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: Observational
• Enrollment (Estimated): 180

Contacts and Locations

• Study Contact: Name: Qihong Ni; Phone Number: +8615801900772; Email: niqihong1989@163.com

Study Locations

• China
  • Shanghai, China
    • Recruiting
    • Renji Hospital
    • Contact: Qihong Ni; Phone Number: +8615801900772; Email: niqihong1989@163.com

Participation Criteria

Eligibility Criteria

• 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

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
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

Outcome Measure	Measure Description	Time Frame
Incidence of PTS	Assessed by the Villalta score	At 24 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of moderate-to-severe PTS	Assessed by the Villalta score	at 6, 12, and 24 months
Clinical classification of Clinical-Etiology-Anatomy-Pathophysiology (CEAP)	Based on clinical symptoms	at 6, 12, and 24 months
Patency rate of the ipsilateral iliofemoral vein	Assessed by color Doppler ultrasound	at 12 months and 24 months
Incidence of PTS	at 6 and 12 months	Assessed by the Villalta score
Recurrence rate of symptomatic Deep Vein Thrombosis (DVT)	Assessed by symptoms combined with ultrasound examination in the ipsilateral limb	at 24 months
Rate of re-intervention	Assessed by documentation of clinical reintervention	at 24 months
Quality of life score	Assessed by Venous Insufficiency Epidemiological and Economic Study Quality of Life questionnaire (VEINES-QOL)	at 6, 12, and 24 months

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of major bleeding	Defined by International Society on Thrombosis and Haemostasis (ISTH) criteria	at 24 months
Incidence of symptomatic Pulmonary Embolism (PE)	Assessed by symptoms combined with contrast-enhanced computed tomography examination	at 24 months
Incidence of symptomatic Venous Thromboembolism (VTE)	Assessed by symptoms combined with ultrasound and contrast-enhanced computed tomography examination	at 24 months
All-cause mortality	All-cause death	at 24 months

Collaborators and Investigators

• Sponsor: RenJi Hospital
• Collaborators: 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

Study Major Dates

• Study Start (Actual): January 1, 2024
• Primary Completion (Estimated): December 31, 2027
• Study Completion (Estimated): December 31, 2028

Study Registration Dates

• First Submitted: May 26, 2026
• First Submitted That Met QC Criteria: May 26, 2026
• First Posted (Actual): June 3, 2026

Study Record Updates

• Last Update Posted (Actual): June 3, 2026
• Last Update Submitted That Met QC Criteria: May 26, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Deep venous thrombosis; Post-thrombotic syndrome; Percutaneous mechanical thrombectomy
• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Embolism and Thrombosis; Venous Insufficiency; Thrombosis; Venous Thrombosis; Postthrombotic Syndrome
• Other Study ID 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