Comparing Carotid Stenting With Endarterectomy in Severe Asymptomatic Carotid Stenosis
Condition: Carotid Stenosis
MeSH terms: Carotid Stenosis; Constriction, Pathologic
Study type: Interventional
Phase: Phase 4

Summary: 
      Purpose of this study:

      Primary:

      • Comparison of cardiovascular mortality and morbidity which includes cardiac and
      neurological morbidity (TIA and CVA) in the two invasive treatments of asymptomatic carotid
      artery stenosis

      Secondary:

        -  Comparison of non cardiovascular morbidity caused by the two invasive techniques

             1. morbidity at the site of incision (infection or local hematoma)

             2. damage to cranial nerves (hypoglossus, vagus)

             3. brain hyperperfusion which is defined as severe headache which is not responsive to
                analgesics with or without nausea and vomiting.

             4. events of bradycardia within the first 24 hours, clinically evident and/or silent

        -  microembolic brain events immediately after the procedure and their relationship with
           morbidity and/or mortality due to TIA's or CVA's

        -  the change in the stenotic carotid artery at the time of follow up with duplex of neck
           arteries

        -  the comparison of the affect of the two procedures on patient life style
    

Detailed description: 
      Background: the surgical treatment of severe carotid artery stenosis (>70%) has been proven
      effective in prevention of cerebral vascular events in asymptomatic patients as compared with
      non invasive treatment (1, 5, 7). The currently accepted surgical treatment is called
      endarterectomy and includes surgery under regional and general anesthesia, in which the neck
      is opened, the common carotid artery, the bifurcation and the internal and external carotid
      artery are exposed, 5000 units of intravenous (IV) heparin is given and the arteries are
      occluded. The diseased artery is opened and the atherosclerotic plaque is excised, after the
      artery is cleaned the opening is sutured and the blood supply is reestablished. At the end of
      the procedure the incision is closed. The patient is transferred to recovery for four hours
      of surveillance, and 500 units/hour of heparin IV is started, which is continued for 12
      hours. After an additional day of surveillance in the department the patient is discharged
      home. Two weeks after the operation the patient is invited to the out patient clinic for
      wound surveillance and to take out the skin staples. After which the patient is under
      surveillance after 3 months, 6 months, and then yearly, which involves a physical examination
      by a physician and a duplex examination of carotid arteries. A regiment of 100mg of Aspirin
      per day is initiated at the time of diagnosis. Complications associated with this procedure:
      a 1-3% of patients develop a transient ischemic accident (TIA) or cerebrovascular accident
      (CVA), cardiac complications depending on individual risk factors (0.5%), bleeding and
      infection at incision site is at the rate of 5%, 2-8% of patients suffer from cranial nerve
      damage (including hypoglossus and vagus), 2-3% of patients suffer from brain hyperperfusion,
      finally, stenosis recurs in 10-15% of patients.

      Recently endovascular technique involving stent placement has been introduced to treat
      carotid artery stenosis. Early studies found this technique to be equal to traditional
      carotid endarterectomy in mortality and morbidity (8). Complications associated with
      endovascular stenting: 1-3% of patients develop a TIA or a CVA, bleeding at artery access
      site is at the rate of 1%, cardiac complications depending on individual risk factors (0.5%),
      1-4% of patients suffer from a periprocedural arterial thromboembolic events, finally, 1% of
      patients suffer from renal function deterioration. Invasive treatment of carotid artery
      stenosis, traditional or endovascular, may be accompanied by microembolic events, which, do
      not necessarily result in cerebral ischemia with evident neurological deficiency. These
      events, however, may be noted on brain CT and may result in cognitive decline (2-4%). The
      role of stent deposition in conjunction with a vascular protective device, in protecting from
      microembolic events is still unclear.

      In this study, price-rapid exchange® (Cordis, FL, USA) will be evaluated in the treatment of
      asymptomatic carotid artery stenosis. Traditional indications for stent placement will be
      used: stenosis of 70% or more demonstrated by carotid artery duplex, CTA or MRA. The stent is
      placed into the area of stenosed carotid artery using percutaneous approach in the operating
      room. The artery is visualized by injecting contrast material, a vascular protective device,
      angioguard® (Cordis, FL, USA), is placed downstream from carotid artery stenosis, the stent
      is inserted and expanded by a balloon, amiia® (Cordis, FL, USA). Furthermore, a completion
      angiography is preformed to visualize the final stent location and the protective vascular
      device is removed. A regiment of 100mg Aspirin, once daily, is initiated before endovascular
      treatment, and then continued as a part of a permanent treatment. Five thousand units of
      intravenous heparin are given at the beginning of the endovascular procedure. Heparin is than
      continued at 500 units per hour for the next 12 hours. The patient is discharged one day
      after the procedure.
    

Intervention name(s): carotid artery stenting; carotid endarterectomy
Intervention type(s): Procedure; Procedure
Intervention description(s): carotid artery angiography, angioplasty and stenting; open surgery including endarterectomy
Other intervention name(s): carotid stent - precise - rapid exchange® (Cordis, FL, USA); carotid artery filter - angioguard® (Cordis, FL, USA)
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: carotid stenosis; asymptomatic; carotid stenting; carotid endarterectomy