Technical Aspects of Percutaneous Carotid Angioplasty and Stenting for Arteriosclerotic Disease



Technical Aspects of Percutaneous Carotid Angioplasty and Stenting for Arteriosclerotic Disease



Rabih A. Chaer and Peter A. Schneider


Carotid angioplasty and stenting with cerebral protection has emerged as a minimally invasive alternative to endarterectomy and is a treatment option for carotid arteriosclerotic disease. Carotid angioplasty and stenting comprises the following steps: (1) preprocedural evaluation, (2) femoral access, (3) arch aortogram, (4) selective common carotid catheterization and angiogram, (5) carotid sheath access, (6) crossing of the carotid stenosis, (7) filter placement, (8) predilatation, (9) stenting, (10) postdilatation, (11) completion angiogram, (12) access site management, and (13) postoperative care and follow-up. These technical aspects of carotid angioplasty and stenting are all important.



Preprocedural Evaluation


Before the procedure, an understanding of the arch, carotid, and cerebral arterial anatomy must be obtained by arteriography, computed tomography angiography (CTA) or magnetic resonance angiography (MRA). Anatomic factors may be considered relative contraindications to carotid angioplasty and stenting, including severe arch atherosclerosis or tortuosity, diffuse common carotid artery disease or tortuosity, severe angulation of the bifurcation, or kinking of the distal internal carotid artery (ICA).


Patients should be started on antiplatelet therapy: aspirin daily and clopidogrel (Plavix) 75 mg/day for 5 days before the procedure. Antihypertensive medications are held on the day of the procedure.


The procedure is performed under local anesthesia with minimal or no sedation to facilitate patient cooperation and continuous neurologic monitoring. Continuous arterial pressure monitoring is performed (by transducing the femoral sheath or placing a separate arterial monitoring line), and electrocardiograph (ECG) leads are placed for cardiac monitoring. Acute reduction of blood pressure with pharmacologic agents must be avoided during the intervention, especially because hypotension and bradycardia are not uncommon following stent placement. The patient’s baseline blood pressure should be documented during the prior clinic visit. If antihypertensive therapy is required during the procedure, a short-acting agent should be used.



Arterial Access


The common femoral artery is the access site in the vast majority of cases, although carotid angioplasty and stenting has also been performed using brachial, radial, or direct common carotid artery access. A micropuncture set (21-gauge needle) is usually used for the initial femoral access; this has significantly reduced the number of complications from femoral access. Following guidewire access, an introducer sheath is placed in the common femoral artery; the introducer sheath is the same size as that intended for the carotid stent placement, usually 6 or 7 French (Fr). In patients whose femoral pulses are absent as a result of aortoiliac occlusion, a transbrachial approach may be considered. This approach is more challenging compared with the transfemoral approach, and it requires a larger selection of reversed angle catheters. Systemic anticoagulation is typically administered after arterial access but before arch manipulation.



Carotid Imaging and Sheath Access


Aortic Arch Angiogram


Arch manipulations with guidewires, catheters, and sheaths carry a risk of neurologic events and should be carefully performed. A 260-cm guidewire is placed in the ascending aorta, followed by a pigtail catheter. An initial arch angiogram is performed with the image intensifier in a left anterior oblique (LAO) position. The image intensifier is rotated until the upside-down U shape formed by the guidewire is as wide as possible, usually at least 30 degrees to 45 degrees, to better expose the origins of the arch vessels. The tortuosity of the arch may be assessed by drawing a horizontal line across the apex of the inner curvature of the arch. Vessels that originate below the horizontal line at the apex of the aortic arch often are more difficult to selectively cannulate (Figure 1). Alternatively, the arch may be assessed by less invasive means using CTA or MRA.


image
FIGURE 1 Assessment of the aortic arch. The type I aortic arch has branches originating from the top of the arch. As the arch becomes more tortuous, the branch vessel origins may be located on the upslope of the ascending aorta. The more inferiorly located and toward the patient’s right side the vessel origin is located, the more difficult the artery is to cannulate.


Selective Common Carotid Catheterization


Selective cannulation of the arch vessels is a critical portion of carotid angioplasty and stenting procedures. Catheterization can usually be accomplished using one of two preshaped catheters: a simple-curve catheter such as a vertebral catheter or a complex-curve catheter such as the reversed-angle Vitek catheter or Simmons catheter (Table 1). The image intensifier is maintained in its fixed position (LAO), and the bony landmarks or road mapping may be used to guide cannulation of the vessel. The catheter of first choice in most cases is a simple-curve catheter, such as a vertebral catheter. The angle formed by the vertebral catheter along with the tip angle on an angled guidewire (Glidewire) is adequate to cannulate the common carotid artery in most patients. Once the guidewire has accessed the common carotid artery, the vertebral catheter is advanced over the guidewire for selective angiograms of the common carotid artery. Be aware that as the cerebral catheter rounds the turn from the aortic arch into the common carotid artery, it tends to straighten out, and the guidewire can jump forward.


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  3. Treatment of Dyslipidemia and Hypertriglyceridemia
  4. Intraoperative Assessment of the Technical Adequacy of Carotid Endarterectomy

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Aug 25, 2016 | Posted by in CARDIOLOGY | Comments Off on Technical Aspects of Percutaneous Carotid Angioplasty and Stenting for Arteriosclerotic Disease

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