PROfunda Femoris Vein Thrombosis Evaluation and Clearance to Improve Outcomes of Endovascular Treatment for Acute Iliofemoral Deep Vein Thrombosis

August 31, 2026 updated by: RenJi Hospital

PROfunda Femoris Vein Thrombosis Evaluation and Clearance to Improve Outcomes of Endovascular Treatment for Acute Iliofemoral Deep Vein Thrombosis: a Multicenter Randomized Controlled Study (The PROTECT Study)

Patients with iliofemoral vein thrombosis are prone to developing post-thrombotic syndrome (PTS). The profunda femoris vein (PFV) is an important inflow of the iliofemoral vein. Profunda femoris vein thrombosis clearance (PFV-TC) may improve the patency of iliofemoral vein and reduce the occurrence of PTS.

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 lower extremity deep vein thrombosis (DVT) can lead to obstruction of veins, causing sudden lower limb swelling. Patients may also develop post-thrombotic syndrome (PTS) manifesting as recurrent lower limb swelling, skin disorders, and even non-healing ulcers, which severely affects the patient's quality of life. Among lower extremity DVT, thrombosis involving the iliofemoral veins is the most severe, with an incidence of PTS as high as 20%-50%. Percutaneous mechanical thrombectomy (PMT) utilizes mechanical aspiration to rapidly remove thrombus, relieve venous obstruction, and restore luminal patency. According to the results of a prospective clinical study, PMT can effectively improve the primary thrombus clearance rate and shorten hospital stay in patients with DVT. Among 329 patients, 192 (58.5%) achieved complete thrombus removal using the AngioJet catheter. PMT was once considered to be the first-line treatment option for DVT. However, the results of the ATTRACT study, published in 2017 in New England Journal of Medicine, sparked considerable controversy regarding the use of PMT for DVT. The ATTRACT study found that there was no significant difference in the incidence of PTS at two years after PMT compared with anticoagulation alone. Although PMT can rapidly remove thrombus, is it unable to improve the long-term outcomes for patients with DVT? According to previous studies, the primary patency rate at 12 months after PMT for acute iliofemoral venous thrombosis ranges from 77% to 85%, while the incidence of PTS at 24 months postoperatively is as high as 40%. Residual thrombus is an important cause of thrombus recurrence, re-occlusion of the vein, and poor clinical outcomes. Previous studies have primarily focused on thrombus clearance in the popliteal vein, superficial femoral vein, common femoral vein, and iliac vein, while neglecting the assessment and clearance of profunda femoris vein (PFV) thrombosis. As the PFV is an important inflow of the iliofemoral vein, whether PFV-TC can improve the patency rate and clinical outcomes of endovascular treatment for acute iliofemoral DVT remains unclear. In a preliminary study, the investigators analyzed and compared two cohorts: one receiving conventional endovascular treatment for acute iliofemoral venous thrombosis, and the other receiving conventional treatment combined with Profunda femoris vein thrombosis clearance (PFV-TC). The results showed that the 24-month patency rate of the iliofemoral vein was 90% vs. 72%, and the incidence of PTS was 11% vs. 32% (P<0.05). These findings were published in November 2025 in European Journal of Vascular and Endovascular Surgery. This study has garnered widespread attention, and de Wolf MAF published an invited commentary on this study, acknowledging the value of this approach in the endovascular treatment of acute iliofemoral DVT. Therefore, the investigators hypothesize that PFV-TC can improve inflow and reduce the incidence of PTS for iliofemoral DVT. However, high-level evidence is still lacking. The present study is a prospective, multicenter, randomized, open-label, evaluator-blinded, 1:1 parallel-controlled clinical trial investigating PFV-TC, aiming to obtain higher-level evidence to guide endovascular treatment of 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.
Interventional

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.
140

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

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

Description

Inclusion Criteria:

  1. Age ≥ 18 years and ≤ 85 years;
  2. Diagnosed with acute iliofemoral DVT involving iliac vein, common femoral vein, and the proximal segment (orifice) of PFV (confirmed by preoperative ultrasound, CT venography, or pre-procedural venography);
  3. Time from symptom onset to endovascular treatment ≤ 14 days;
  4. Patient receives endovascular treatment with PMT;
  5. Patient provides written informed consent.

Exclusion Criteria:

  1. Presence of pre-existing PTS in the limb scheduled for treatment, or a history of symptomatic DVT in the same limb;
  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 media, or other relevant agents;
  4. Concomitant severe pulmonary embolism with hemodynamic compromise, such as hypoxia or hypotension;
  5. Intolerance to endovascular intervention due to concurrent acute systemic illness, severe dyspnea, or other contraindications;
  6. Concomitant severe renal insufficiency with creatinine clearance < 30 ml/min;
  7. Presence of active bleeding, severe hepatic insufficiency, bleeding diathesis, or other coagulation disorders;
  8. Concomitant severe anemia (hemoglobin < 8.0 mg/dL) or thrombocytopenia (platelet count < 80,000/mL);
  9. History of subarachnoid hemorrhage, intracranial hemorrhage, intracranial vascular malformation, or intracranial aneurysm;
  10. Pregnancy;
  11. Presence of other diseases (e.g., advanced malignancy, cardiac insufficiency) with an estimated life expectancy < 24 months;
  12. Participation in another clinical trial of a drug or medical device within the past 1 month that may interfere with the present study;
  13. Unwillingness 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

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
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.
Experimental: PMT with PFV-TC group
PMT with PFV-TC group (experimental group)
Procedure: Percutaneous mechanical thrombectomy with profunda femoris vein thrombosis clearance (PMT with PFV-TC)
PMT with PFV-TC group (experimental group): Based on the control group, access is obtained via the contralateral common femoral vein using a crossover technique, or via a popliteal-profunda communicating vessel approach to PFV. The thrombus status of the PFV is assessed, and PMT is performed on the PFV thrombosis. After thrombectomy, venography is performed to evaluate the patency of the PFV. Successful PFV-TC is defined as the presence of continuous flow from the distal PFV to the CFV, including complete clearance (no residual thrombus) and partial clearance (continuous flow with residual thrombus). Conversely, the absence of continuous flow is defined as failed PFV-TC.
Active Comparator: PMT without PFV-TC group
PMT without PFV-TC group (control group)
Procedure: Percutaneous mechanical thrombectomy without profunda femoris vein thrombosis clearance (PMT without PFV-TC)
An appropriate puncture approach is selected, including the ipsilateral calf vein, ipsilateral popliteal vein, or ipsilateral femoral vein. Under ultrasound guidance, a vascular sheath is inserted after puncture, and systemic heparinization is performed. Using a guidewire and catheter, the guidewire is advanced antegradely into the inferior vena cava to establish a pathway. After the pathway is established, PMT is performed using a mechanical thrombectomy device. Acceptable thrombectomy devices include commercially available mechanical aspiration thrombectomy devices such as the AngioJet catheter (Boston Scientific, USA) and the Indigo catheter (Penumbra Inc, USA). After thrombectomy, the outcome is evaluated by venography. If iliac vein stenosis greater than 50% is detected, balloon dilation is performed using a balloon matched to the normal vessel diameter. If residual stenosis remains greater than 50% after balloon dilation, stent implantation is performed.

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 Post-Thrombotic Syndrome (PTS)
Time Frame: at 24 months
Assessed by the Villalta score. The Villalta scale is the recommended tool for diagnosing and grading the severity of PTS. It is a composite score based on 11 items (5 patient-reported symptoms and 6 clinician-assessed signs), each rated from 0 (absent) to 3 (severe), yielding a total score ranging from 0 to 33. A score of 0-4 indicates no PTS, whereas a score of ≥5 or venous ulcer confirms the diagnosis of PTS. Specifically, scores of 5-9 indicate mild PTS, 10-14 indicate moderate PTS, and a score of ≥15 or venous ulcer indicates severe PTS. Higher scores reflect greater disease severity.
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
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
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
Incidence of PTS
Time Frame: at 6 and 12 months
Assessed by the Villalta score
at 6 and 12 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). The minimum value is 0 and the maximum value is 100. Higher score means a better outcome.
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.
June 24, 2026

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.
June 30, 2029

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, 2029

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.
September 2, 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.
August 31, 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.
August 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 PROTECT 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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