Techniques in cerebral protection
Introduction
Carotid artery stenting (CAS) is considered a valid therapeutic option for the treatment of the stenoses of the extracranial carotid artery. However, it has an incidence of neurological complications due to distal embolization which ranges from 3.2 to 10% [1], [2].
To reduce the rate of periprocedural neurological complications, various systems of cerebral protection have been proposed; the purpose of these systems is to capture the emboli before they reach the brain.
The first system was described by Théron [3] in 1990, who introduced the concept employing temporary balloon occlusion of the distal internal carotid artery (ICA) during percutaneous transluminal angioplasty.
After this initial experience, several studies have been carried out using different protection devices, which showed a reduction of the neurological periprocedural complication rate. The global carotid artery stent registry described a perioperative stroke and death rate of 5.9 and 2.23%, respectively, in those procedures performed without and with protection devices [4].
Boltuch et al. [5] evaluated 651 patients treated both with (N = 180) and without (N = 471) cerebral protection and found better results for the protected population: technical success 99% versus 95%; complication rate 10% versus 18.3%; TIA 2.8% versus 3.2%; MAE 0.6% versus 2.1%.
Cerebral protection devices (CPD) can be divided into three different types: filters, distal occlusion balloons and proximal protection systems.
In filter systems, flow is maintained and emboli are captured and removed together with the device by retraction of the system. Balloon occlusion devices and proximal protection system block flow in the ICA and emboli are aspirated before balloon deflation and catheter removal.
In this paper, we described the more commonly used CPDs, the techniques of use, and the potential technical and clinical complications.
Section snippets
Distal occlusion balloons
Distal occlusion balloons represent the first class of protection devices used routinely in clinical practice.
They consist of a 0.014 in guide-wire equipped with a distal balloon that is inflated through a small channel present within the wire.
Once the lesion is crossed with the guide-wire, the balloon is positioned above the lesion and inflated to completely occlude the ICA, thus avoiding the passage of microemboli. After treatment of the lesion by angioplasty and stenting, a catheter is
Discussion
Cerebral protections cannot prevent all embolic events that may occur during the different steps of CAS procedures. Up-to-date data on device effectiveness are still limited and results of clinical studies and experimental evaluations of protection devices are controversial [9], [10]. Further details about their effectiveness are discussed elsewhere in this issue.
Despite the fact that CPDs have been used in clinical practice for several years, they are still “young” devices and they are subject
Summary
Carotid artery angioplasty and stenting procedures always produce distal embolization, although most embolization does not produce clinical sequelae. Several studies have proved that the use of cerebral protection devices drastically reduces the incidence of distal microembolization.
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Spontaneous cervical and cerebral arterial dissections. Diagnosis and management.
2013, Neuroimaging Clinics of North AmericaCitation Excerpt :Finally, unlike stenting for carotid artery stenosis, it is generally agreed that the risk of worsening the dissection with the use of distal embolic protection devices outweighs any benefits that might stem from their deployment.8,81,82 Investigators have hypothesized that perhaps proximal protection devices might prove beneficial in this patient population.83 Endovascular management has largely replaced surgical treatment of arterial dissections.
Imaging of the carotid artery
2012, AtherosclerosisCitation Excerpt :Pre-dilatation should be carried out using low-profile balloon (2–3.5 mm). Cerebral protection devices must be adopted to reduce the risk for peri-procedural ischemic events [103] and can be divided into three different types on the basis of their technical aspects: filters, distal occlusion balloons and proximal protection systems. Using filter systems, the blood flow is maintained through the ICA and emboli are captured and removed together with the device.
Impact of endovascular technique in vascular surgery training at a large University Hospital in Brazil
2011, Journal of Surgical EducationCitation Excerpt :ES techniques require shorter operating times and shorter duration of stay,8,18 allowing for greater numbers of procedures to be performed each day and an increased turnover of hospital beds. Our findings of increased total numbers of patients treated because of increases in ES procedures, while OSs have remained stable, is consistent with other studies.7,19 We have noticed that open vascular cases are increasing in complexity.
Carotid artery stenting: Rationale, technique, and current concepts
2010, European Journal of RadiologyCitation Excerpt :Theron was one of the pioneers who developed and used a temporary balloon occlusion device as a cerebral protection during angioplasty and stenting for carotid stenosis [27,28]. Three types of cerebral protection devices (CPDs) are nowadays available: distal filters and distal or proximal occlusion balloons, each has its advantages and disadvantages [29]. Even though CEA became the standard method of treating carotid artery stenosis when the large randomized trials were published [3,4,12], these trials evaluating CEA have systematically excluded patients considered to be at “high risk for surgery“(Table 1).
Current Management of Extracranial Carotid Occlusive Disease
2009, Journal of the American College of SurgeonsCitation Excerpt :Despite the fact that EPDs likely provide additional cerebral protection, there is still a risk of stroke associated with CAS secondary to particle embolization from the aortic arch. In addition, EPDs have inherent risks and complications of their own, such as inability to cross the target lesion, failure to capture emboli through filter pores, and vasospasm or injury to the vessel wall.23 In addition, it is still debatable whether the routine use of EPDs is required at all.
Experimental in Vivo Evaluation of a Distal Protection Device
2008, Journal of Vascular and Interventional Radiology