A Prospective, Multicenter, Single-Arm Trial of Peripheral Vein Thrombectomy Stent System in Deep Venous Thrombosis

A Prospective, Multicenter, Single-Arm Trial to Evaluate the Safety and Efficacy of the Peripheral Vein Thrombectomy Stent System in the Treatment of Deep Venous Thrombosis

To evaluate the safety and efficacy of peripheral vein thrombectomy stent system produced by Shanghai Tendfu Medical Technology Co., Ltd. in the treatment of acute or subacute deep venous thrombosis.

Study Overview

• Status: Completed
• Conditions: DVT - Deep Vein Thrombosis
• Intervention / Treatment: Device: Peripheral Vein Thrombectomy Stent System

Detailed Description

This project is being conducted at qualified clinical research institutions, where investigators are using a thrombectomy device developed by Shanghai Tengfu Medical Technology Co., Ltd. to treat subjects with deep vein thrombosis; it is a prospective, multicenter, single-arm clinical study utilizing a target performance value design, with subject enrollment managed via an online registration system. The primary endpoint-thrombectomy efficacy rate assessed immediately post-procedure-is used to determine whether the investigational device meets the efficacy standard, while device efficacy is further evaluated by the recurrence rate of thrombosis at the target lesion at 1, 3, and 6 months post-procedure, the incidence of post-thrombotic syndrome at 1, 3, and 6 months, device success rate, procedural success rate, and Venous Clinical Severity Score (VCSS) and Chronic Venous Insufficiency Questionnaire (CIVIQ-20) scores at 1, 3, and 6 months. Device safety is assessed based on the incidence of Major Adverse Events (MAEs) at 30 days post-procedure, as well as the incidence of adverse events and serious adverse events at 1, 3, and 6 months post-procedure.

• Study Type: Interventional
• Enrollment (Actual): 132
• Phase: Not Applicable

Contacts and Locations

Study Locations

• China
  • Shanghai, China
    • Shanghai Pudong Hospital
  • Fujian
    • Xiamen, Fujian, China
      • Xiamen Cardiovascular Hospital Xiamen University
  • Guangzhou
    • Guangzhou, Guangzhou, China
      • The First Affiliated Hospital of Guangzhou Medical University
  • Jiangsu
    • Suzhou, Jiangsu, China
      • The Second Affiliated Hospital of Soochow University
  • Shaanxi
    • Xi'an, Shaanxi, China
      • The First Affiliated Hospital of Xi'an Jiaotong University
  • Shandong
    • Qingdao, Shandong, China
      • The Affiliated Hospital of Qingdao University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

1. Subjects aged between 18 and 80 years.
2. Patients diagnosed with deep venous thrombosis (DVT) within 30 days of onset via color Doppler ultrasound (CDUS) or CT venography (CTV) imaging.
3. Target lesions involving the inferior vena cava, common iliac vein, external iliac vein, common femoral vein, superficial femoral vein, or popliteal vein.
4. Subjects capable of understanding the purpose of the trial, who voluntarily participate and sign an informed consent form, and are willing to undergo follow-up evaluations.

Exclusion Criteria:

1. Patients diagnosed with chronic-phase deep venous thrombosis (DVT) (symptom onset >30 days).

2. Patients with bilateral lower extremity DVT requiring thrombus removal in both limbs.

3. Patients with known bleeding disorders or bleeding tendencies (platelet count <50×10⁹/L or INR >3).

4. Severe hepatic or renal dysfunction Renal insufficiency (estimated glomerular filtration rate [GFR] <30 mL/min); Active liver disease or ALT >3 × upper limit of normal (ULN).

5. History of heart failure, stroke, and/or myocardial infarction within 1 month, or planned coronary/carotid revascularization or major cardiovascular/cerebrovascular surgery.

6. Target lesions involving veins with a diameter <3 mm.

7. Patients with a life expectancy <12 months (e.g., malignancy).

8. Patients with congenital inferior vena cava (IVC) hypoplasia/malformation or other congenital IVC/iliac vein abnormalities.

9. Allergy to anticoagulants or iodine-based contrast agents.

10. Bedridden patients unlikely to regain limb mobility within 1 month post-procedure.

11. Patients with pre-existing venous stents or IVC filters that may interfere with device deployment.

12. Patients with recurrent ipsilateral DVT.

13. Pregnant or lactating women.

14. High-risk pulmonary thromboembolism (PTE) (manifested by shock/hypotension: systolic blood pressure <90 mmHg or >40 mmHg drop from baseline lasting >15 minutes).

15. Severe post-thrombotic syndrome (PTS) (defined as Villalta score >14 points and/or skin ulcers).

16. Patients who underwent percutaneous mechanical thrombectomy within 1 month.

17. Contraindications to anticoagulation (e.g., heparin-induced thrombocytopenia [HIT]).

18. Contraindications to thrombolysis:

    Allergy to thrombolytic agents; High bleeding risk or active bleeding within 2 - 4 weeks (e.g., intracranial, gastrointestinal, or urinary tract hemorrhage); Recent major surgery, biopsy, CPR, or non-compressible puncture; Severe trauma within 2 - 4 weeks; Uncontrolled hypertension (>160/110 mmHg); Bacterial endocarditis; Aortic dissection, aneurysm, or arteriovenous malformation.

19. History of nickel-titanium (Nitinol) alloy allergy.

20. Participation in other ongoing drug/device clinical trials.

21. Patients deemed ineligible by the investigator.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Peripheral Vein Thrombectomy Stent System; Tendfast™ Peripheral Vein Thrombectomy Stent System

Device: Peripheral Vein Thrombectomy Stent System; Tendfast™ Peripheral Vein Thrombectomy Stent System (Tendfast™) is a mechanical thrombectomy system consisting of a peripheral vein thrombectomy stent and a thrombus aspiration catheter. Guided by a guidewire, the stent is delivered to the thrombus, deployed against the vessel wall to engage, scrape, and collect the thrombus into its mesh for removal, after which manual negative-pressure aspiration through the catheter clears residual thrombus and restores blood flow.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Thrombus clearance rate	Thrombus clearance (immediately post-procedure): The thrombus clearance rate is divided into 3 grades: Grade I is <50%; Grade II is 50%-95%; Grade III is >95%. The lower extremity veins are divided into 7 segments: inferior vena cava, common iliac vein, external iliac vein, common femoral vein, proximal superficial femoral vein, distal superficial femoral vein, and popliteal vein. Pre- and post-procedure luminal patency is visually assessed by venography: a patent lumen is scored as 0 points, partial occlusion (<50%) as 1 point, severe occlusion (50%-95%) as 2 points, and complete occlusion (95%-100%) as 3 points. The formula for the thrombus clearance rate is: (preoperative venous patency score - postoperative venous patency score) / preoperative venous patency score × 100%. A thrombus clearance rate of Grade II or above is considered effective.	immediately after the surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
thrombus recurrence rate	Compared with before discharge, worsening of symptoms with imaging confirmation that the target lesion thrombus occludes the vessel or interrupts blood flow, requiring repeat intervention.	1, 3, and 6 months
Post-thrombotic syndrome (PTS)	Occurrence and severity grading assessed by the Villalta score. PTS is defined as a Villalta score >4. The Villalta score includes 5 symptoms (pain, muscle cramps, heaviness, paresthesia, itching) and 6 signs (pretibial edema, pigmentation, lipodermatosclerosis, redness of the skin, superficial venous dilatation, calf muscle tenderness). Severity is classified as mild (5-9), moderate (10-14), and severe (>14 and/or presence of skin ulcer).	1, 3, and 6 months
Device success	Successful delivery of the thrombectomy device to the target lesion, successful deployment, and successful withdrawal of the delivery system.	immediately after the surgery
Procedural success	Immediate post-procedure thrombus clearance rate of Grade II or above and no major adverse event before discharge	immediately after the surgery
Venous Clinical Severity Score (VCSS)	Evaluation of clinical symptoms by comparing improvement from baseline to post-treatment. VCSS includes 10 clinical elements (pain, varicose veins, edema, skin pigmentation, inflammation, induration, number of active ulcers, ulcer size, and use of compression therapy), each scored 0-3 by severity, with a total score of 30.	1, 3, and 6 months
Chronic Venous Insufficiency Questionnaire (CIVIQ-20) score	Improvement/change compared with pre-operation based on the CIVIQ-20 score. CIVIQ is a specific, self-administered quality-of-life questionnaire for patients with chronic venous disease of the lower extremities. It includes 20 items across 4 domains-social, psychological, physical, and pain-and mainly reflects the impact of chronic venous insufficiency on patients' quality of life.	1, 3, and 6 months
Major adverse events (MAE) at 30 days	all-cause death, major bleeding, new-onset symptomatic pulmonary embolism, and target lesion thrombus recurrence. Major bleeding is defined as intracranial hemorrhage or severe bleeding that leads to death, surgery, discontinuation of treatment, or transfusion. Transfusion [15] is defined as two or more units of whole blood (400 mL) or red blood cells (240 mL). Symptomatic pulmonary embolism is defined as pulmonary embolism with clinical symptoms such as dyspnea, chest pain, hemoptysis, panic, cough, or syncope. Target lesion thrombus recurrence is defined as worsening symptoms compared with before discharge, with imaging confirmation that the target lesion thrombus occludes the vessel or interrupts blood flow and requires repeat intervention.	30 days
Adverse event rate within 12 months after surgery	Adverse event rate within 12 months after surgery	12 months after surgery
Serious adverse event rate within 12 months after surgery	Serious adverse event rate within 12 months after surgery	12 months after surgery

Collaborators and Investigators

• Sponsor: Shanghai TENDFO Medical Technology Co., Ltd.

Study record dates

Study Major Dates

• Study Start (Actual): August 1, 2022
• Primary Completion (Actual): August 30, 2023
• Study Completion (Actual): August 30, 2023

Study Registration Dates

• First Submitted: September 29, 2026
• First Submitted That Met QC Criteria: October 2, 2026
• First Posted (Actual): October 5, 2026

Study Record Updates

• Last Update Posted (Actual): October 5, 2026
• Last Update Submitted That Met QC Criteria: October 2, 2026
• Last Verified: September 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Embolism and Thrombosis; Thrombosis; Venous Thrombosis
• Other Study ID Numbers: TF02-001A

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