Carotid Artery Stenting

Transcription

1 Carotid Artery Stenting JESSICA MITCHELL, ACNP CENTRAL ILLINOIS RADIOLOGICAL ASSOCIATES External Carotid Artery (ECA) can easily be identified from Internal Carotid Artery (ICA) by noticing the branches. The ECA has branches leading to neck, esophagus, jaw and face, while the ICA has no branches and runs into the Circle of Willis. The Road to Carotid Artery Stenting Acceptable alternative to CEA is CAS with embolic protection among symptomatic patients with a stenosis of 70-99% or those with high-risk factors and stenosis of 50-69%1 Many early comparisons between CAS and CEA involved poor patient selection, lack of embolic protection and operator inexperience. This caused the clinical trials to represent less than favorable outcomes for CAS. Imaging techniques for identifying carotid artery stenosis Whether the patient has symptomatic or asymptomatic stenosis, imaging is essential to further delineate the degree of stenosis: Carotid ultrasound MRA CTA DSA How does it present? Carotid ultrasound Asymptomatic Incidental finding By imaging Clinically with bruit Symptomatic Focal neurological deficit TIA Ischemic stroke Identify a focal increase in blood flow velocity (peak systolic) Non invasive and inexpensive Mild <50 Moderate 50-69% Severe > 70% Occlusion 1

2 MRA CTA Can be done with or without gadolinium If used in conjunction with MRI helpful in identifying stroke Produces a reproducible three-dimensional image of the carotid bifurcation Less operator dependent Limitations included that it only identifies flow and can over estimate stenosis Identify the complete arterial tree from the heart to distal intracranial arterial branches IV contrast necessary Limitations: Severe calcifications, CHF, Operator dependent and CKD Digital Subtraction Angiography Provides imaging of the entire carotid artery system Identifies collateral circulation and plaque morphology NASCET criteria Invasive and expensive Risks include embolization with subsequent stroke, repeat exposure to contrast if planning intervention in the future, hematoma and injury to blood vessel When to treat? AHA guidelines > 70% stenosis with asymptomatic stenosis Symptomatic stenosis >50% Indications for CAS Risks of Carotid Artery Stenting Patient with high-grade asymptomatic (more than 70%) or symptomatic carotid artery stenosis (greater than 50%). high surgical patient risk, such as severe pulmonary disease, recent myocardial infarction, unstable angina, or severe congestive heart failure; history of prior neck radiation a history of damage to contralateral vocal cords; the presence of a tracheostomy, contralateral carotid occlusion; previous CEA with recurrent stenosis Poor circle of Willis Clinical High Risk Factors AGE 70 Allergy to IV Contrast Dementia Multiple lacunar strokes Renal failure Angiographic High Risk Features 2 acute 90 bends Contralateral stenosis/occlusion Circumferential calcification Difficult vascular access ie Type 3 arch Intravascular filling defect (thrombus) 2

3 Pre- procedural preparation Platelet inhibition testing Aspirin Plavix Plavix non-responder, Brilinta With therapeutic assay levels prior to the procedure in elective setting Elective: 5-6 days Emergent: Load Assess Creat, GFR, INR, H/H and Platelets Contrast allergy Any previous treatment for PAD, access Smoking cessation Used frequently in Neurointerventional Surgery Verify Now test Measures the P2Y12 platelet receptor blockade. Assesses patient response to antiplatelet therapy including clopidogrel (Plavix ), prasugrel (Effient ) and ticagrelor (Brilinta ). Measures the platelet response to aspirin by an arachidonic acid initiated reaction. Factors affecting decreased responsiveness: Drug Interactions (e.g. proton pump inhibitors) Genetic differences Pre-existing health conditions (e.g. diabetes) Non-compliance Procedure Video: Pre and Post angiography Case studies from INI Experience 3

4 CAS Systems & Embolic Protection Devices Company Stent Format Embolic Protection Covidien/Medtro nic Abbott Vascular Protégé RX RX Acculink Xact Tapered & Tapered & SpiderFX RX Accunet Emboshield / Nav6 Type Boston Scientific Wallstent Wire EZ Cordis Precise Precise Pro RX Autotapering & Angioguard XP Angioguard RX Barewire Invatec Mo.Ma Ultra Proximal occlusion Lumen Biomedical (distributed by Invatec) FiberNet EPS Medtronic Interceptor Plus Nursing considerations during the peri-procedural period Conscious sedation is administered Anticoagulation with Heparin is required in addition to Dual antiplatelet therapy Hemodynamic monitoring External pacemaker W.L. Gore & Associates Gore Flow Reversal System ICA flow reversal Possible complications Post-procedure monitoring Minor complications Carotid artery spasm Sustained hypotension / bradycardia Carotid artery dissection Contrast encephalopathy (very rare) Minor embolic neurological events (TIAs) Major complications Major embolic stroke Intracranial hemorrhage Hyper perfusion syndrome Carotid perforation (very rare) Acute stent thrombosis (very rare) Complications at the site of the vascular access Admit to Neuro ICU Maintain Normotension Baseline carotid ultrasound Continue dual Anti-platelets Neuro checks hourly Platelet assay monitoring Femoral sheath removal Follow- up Routine carotid ultrasounds are essential. Initially we monitor at 1 month then every 6 month for 2 years then annually. Close surveillance is required to monitor for intimal hyperplasia. Intimal hyperplasia is a common consequence of vascular injury and vascular activation, and can be seen as a component of the pathology in many distinct vascular disorders. From: Cardiovascular Pathology (Fourth Edition), 2016 Main predictors for the development of intimal hyperplasia requiring additional treatment include: length of target lesion and DM. Continued anti-platelet medications Long term management: In addition to routine carotid ultrasound exams and anti-platelet Ongoing medical management is ESSENTIAL! 4

5 The purpose of CREST 2 CREST-2 IS DESIGNED TO COMPARE THREE DIFFERENT METHODS OF STROKE PREVENTION TO FIND THE SAFEST AND MOST EFFECTIVE TREATMENT. THE STROKE PREVENTION METHODS INCLUDE INTENSIVE MEDICAL MANAGEMENT ALONE COMPARED TO INTENSIVE MEDICAL MANAGEMENT IN COMBINATION WITH A REVASCULARIZATION PROCEDURE EITHER CEA OR CAROTID ARTERY STENTING. ALL STUDY PARTICIPANTS WILL RECEIVE INTENSIVE MEDICAL MANAGEMENT: AGGRESSIVE BP MGMT, STATIN THERAPY AND ANTIPLATELET MEDICATION ON TO MEDICAL MANAGEMENT.. 5