The Dedicated Venous Sinus Thrombectomy Stent for Endovascular Treatment of Cerebral Venous Sinus Thrombosis.

Study Overview
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Brief Summary
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A prospective, single-center, open-label,randomized, controlled,non-inferiority clinical trial will be conducted to evaluate the safety and efficacy of a dedicated venous sinus thrombectomy stent for endovascular treatment of cerebral venous sinus thrombosis.

Detailed Description
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Endovascular mechanical thrombectomy is reserved for the treatment of refractory cerebral venous sinus thrombosis (CVST) in the scenario of clinical deterioration in spite of appropriate anticoagulant therapy. However, due to the vascular anatomic and pathophysiological differences, the present used devices,such as stent retriever for arterial occlusion ,aspiration system and balloon catheter cannot provide optimal restoration of venous outflow for high load venous sinus thrombosis.This is a prospective, single-center, open-label, randomized, controlled , non-inferiority clinical trial to evaluate the safety and efficacy of the dedicated venous sinus thrombectomy stent ,which is a novel NiTi- braided Stent Retriever compared to balloon catheter used before in our center. Patients are eligible if they have a radiologically proven CVST, a high probability of poor outcome. The trial aims to randomize 60 patients with a 1:1 allocation to receive the dedicated venous sinus thrombectomy stent or balloon catheter. The primary outcome is the success rate of immediate recanalization.The most important secondary outcomes are mRS and mortality rate at 90 days. The intracranial hemorrhage and other adverse events after post-operative 24 hours and 7 days are the principal safety outcomes.

Official Title
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Safety and Efficacy of the Dedicated Venous Sinus Thrombectomy Stent for Endovascular Treatment of Cerebral Venous Sinus Thrombosis.

Conditions
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Cerebral Venous Sinus Thrombosis

Intervention / Treatment
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* Device: the dedicated venous sinus thrombectomy stent
* Device: balloon catheter thrombectomy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Cerebral venous sinus thrombosis (from onset to randomization less than 28 days) confirmed by cerebral angiography, magnetic resonance venography or computed tomographic venography Severe form of CVT with a high chance of incomplete recovery, as defined by the presence of one or more of the following risk factors Clinical deterioration or progression despite anticoagulation Stupor, Coma (Glasgow coma scale < 9) or mental status disorder Involvement of multiple sinus veins results in severe high cranial pressure and rapid vision loss Venous infarction or intracranial hemorrhage with high load venous sinus thrombosis Thrombosis of the straight sinus The subject (or his/her guardian) agrees to participate in this study and signs the informed consent Exclusion Criteria: Age less than 18 years Duration from onset to randomization more than 28 days Recurrent CVST Pregnancy (women in the puerperium may be included) Isolated cavernous sinus thrombosis or isolated cortical vein thrombosis Clinical and radiological signs of impending transtentorial herniation due to large space-occupying lesions and 4th ventricle compression and hydrocephalus, which requires emergency surgery Recent (< 2 weeks) major surgical procedure (does not include lumbar puncture) or severe cranial trauma Contraindication for anti-coagulant or thrombolytic treatment documented generalized bleeding disorder concurrent thrombocytopenia (<100 x 10E9/L) severe hepatic or renal dysfunction, that interferes with normal coagulation gastrointestinal tract hemorrhage (< 3 months, not including hemorrhage from rectal hemorrhoids) Any known serious condition (such as terminal cancer) with a poor short term (1 year) prognosis independent Known allergy against contrast used during endovascular procedures or the thrombolytic or anticoagulation drug used Previously legally incompetent prior to CVST No informed consent Other conditions judged by the researcher to be unsuitable for inclusion.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: the dedicated venous sinus thrombectomy stent<br>Patients diagnosed with acute or subacute venous sinus thrombosis within 28days from the onset of symptoms to endovascular treatment, regardless of whether anticoagulation has been performed. The dedicated venous sinus thrombectomy stent can be used to remove the thrombus to restore sinus blood flow. | Device: the dedicated venous sinus thrombectomy stent<br>* the dedicated venous sinus thrombectomy stent in conjunction with aspiration for CVST patients within 28 days of symptom onset.<br>|
| Active Comparator: balloon catheter thrombectomy<br>Intracranial thrombectomy was balloon catheter in conjunction with aspiration performed with a control product | Device: balloon catheter thrombectomy<br>* Intracranial thrombectomy was conducted by using a balloon catheter in conjunction with aspiration as control group.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Success rate of immediate recanalization | 3-grade classification scheme that considers different grades for patients with complete recanalization, partial recanalization and no recanalization. Complete recanalization defined as blood flow without any interruption, Partial recanalization defined as small interruptions of continuous blood flow and narrowing of the venous lumen No recanalization defined as interrupted blood flow. | immediately intra-operative | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The proportion of functional independence (modified Rankin score 0-2) | 0-No symptoms; 1-No significant disability; 2-Slight disability; 3-Moderate disability; 4-Moderately severe disability; 5-Severe disability; 6-Dead. | up to 7 days and 90 days post-procedure | 
| The time of thrombectomy procedure | The time of thrombectomy procedure refers to the time from entry of thrombectomy device to vascular recanalization) or the end time of surgery for patients with no vascular recanalization | intra-operative | 
| Changes in NIHSS score | Changes in NIHSS score 7days or at discharge and 90 days post-procedure compared with pre-procedure. | pre-procedure, up to 7 days and 90 days post-procedure | 
| Success rate of instrument operation | Device operation success = the number of devices completed conveying to the occlusive segment of the sinus, releasing and retracting in the group/the number of all test devices used in the group ×100% | intra-operative | 
| The proportion of symptom-free and improved | The symptoms include headache, visual dysfunction, tinnitus, cognitive disorder and epilepsy, etc. | up to 7 days and 90 days post-procedure | 
| CSF opening pressure | Change of CSF opening pressure 7 days or at discharge post-procedure compared with pre-procedure by lumbar puncture | up to 7days | 
| Modified Rankin Scale | Distribution of Modified Rankin Scale | up to 7 days and 90 days post-procedure | 
| The incidence of symptomatic intracranial hemorrhage | Symptomatic intracranial hemorrhage within 7 days post-procedure, specifically intracranial hemorrhage (intracranial parenchymal hematoma, subarachnoid hemorrhage, an ventricular hemorrhage) accompanied by neurological deterioration (NIHSS score increased by ≥4 points compared with pre-procedure. | within 7 days post-procedure | 
| Peri-procedural complications | Procedure associated complications: vasospasm, dissection, perforation and emboli to new territory. | intra-operative and 7 days post-procedure | 
| All cause mortality | All cause mortality within 90 days post-procedure | within 90 days post-procedure | 
| Incidence of device defects | Defects of research devices during clinical trials, such as operational difficulties, broken devices and any incident related with device defects. | intra-operative | 
| Incidence of SAE (serious adverse events) or AE (adverse events) | Incidence of SAE (serious adverse events) or AE (adverse events) intra-operative, 24 hours, 7 days and 90 days post-procedure | intra-operative, 24 hours, 7 days and 90 days post-procedure | 
| The recurrence rate of CVST | The recurrence rate of CVST confirmed by clinical manifestations and imaging examinations | up to 7 days and 90 days post-procedure | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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cerebral venous sinus thrombosis, thrombectomy, endovascular treatment