Introducer Curving Technique for Tilt of Transfemoral Günther Tulip Inferior Vena Cava Filter

Study Overview
=================
Brief Summary
-----------------
It has been demonstrated that implantation of inferior vena cava filter was safe and effective in the prevention or reduction of fatal pulmonary thromboembolism in numerous clinical researches. When acute deep venous thrombosis need transcatheter thrombolysis, transfemoral Günther Tulip Filter implantation could avoid catheter across the Günther Tulip Filter. Although incidence of significant filter tilting (>10°) is not high (13%-16%), severe tilting of the Günther Tulip Filter may be associated with difficulty or sometimes impossibility of retrieval. It has been reported that a simple technique of keeping tension of the delivery system may prevent significant tilting of the transjugular Günther Tulip Filter in an in-vitro study. But no clinical study of prevention transfemoral Günther Tulip Filter from tilting has been reported. The investigators conducted a randomized, controlled study to test whether the introducer curving technique is useful to decrease the extent of tilting of transfemoral Günther Tulip Filter.

Detailed Description
-----------------
The study was designed as a double-blind randomized controlled trial, with research assessors and patients intended to be blind to the intervention status. The staff members performing the assessment were not involved in implementing any aspect of the intervention. 108 patients were randomized to accept curving introducer Günther Tulip Filter and transcatheter thrombolysis or straight introducer Günther Tulip Filter and transcatheter thrombolysis. The assessments include the tilting angle between the axes of inferior vena cava and Günther Tulip Filter after implantation; the tilting angle between the axes of inferior vena cava and Günther Tulip Filter before retrieval; the fluoroscopy time of Günther Tulip Filter retrieval; the rate of retrieval hook adhering vascular wall; the success rate of retrieval.

Official Title
-----------------
Introducer Curving Technique for Tilt of Transfemoral Günther Tulip Inferior Vena Cava Filter：A Randomized Double-Blind Comparison

Conditions
-----------------
Deep Venous Thrombosis

Intervention / Treatment
-----------------
* Device: curving introducer Günther Tulip Filter
* Device: straight introducer Günther Tulip Filter


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: acute lower extremity deep vein thrombosis, diagnosed by vascular ultrasound and clinical history Exclusion Criteria: both lower extremities deep vein thrombosis Inferior Vena Cava thrombosis refractory hypertension (blood pressure > 180/110mmHg) contraindication of thrombolysis the diameter of Inferior Vena Cava > 35mm or < 14mm Inferior Vena Cava venous anomalies

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: curving introducer<br> | Device: curving introducer Günther Tulip Filter<br>* The Günther Tulip filter (Vena Cava MReye Filter Set; William Cook Europe, Bjaeverskov, Denmark) The amplitude of introducer curvature was 5°-15° less than the angle between the inferior vena cave axis and the approached iliac vein axis and the distance between the vertex of the curved angle and the hook of the filter was 2-4cm less than the distance between the level of the renal vein confluence and the furcation of inferior vena cave.<br>|
| Placebo Comparator: straight introducer<br> | Device: straight introducer Günther Tulip Filter<br>* The Günther Tulip filter (Vena Cava MReye Filter Set; William Cook Europe, Bjaeverskov, Denmark)<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| the tilting angle between the axes of Inferior Vena Cava and Günther Tulip Filter after implantation |  | just after filter implantation （up to 24 hours） | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| the tilting angle between the axes of Inferior Vena Cava and Günther Tulip Filter before retrieval |  | just before filter retrieval （up to 90 days） | 
| the fluoroscopy time of Günther Tulip Filter retrieval |  | just after filter retrieval（up to 90 days） | 
| the rate of retrieval hook adhering vascular wall |  | just after filter retrieval（up to 90 days） | 
| the success rate of retrieval |  | just after filter retrieval（up to 90 days） | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Filter Tilt, Preventional efficiency, Günther Tulip filter, Transfemoral Approach