Carotid revascularization

With the ongoing refinement of endovascular devices and techniques for carotid revascularization, catheter-based therapy has become technically feasible in most patients. Notwithstanding, appropriate case selection is required to ensure procedural safety, Here within we review new concepts pertaining to patient selection and technical procedural considerations that we consider crucial for enhancing clinical outcomes following carotid stenting,... 

The evolution of endovascular carotid revascularization historical perspectives... 

Carotid revascularization, initially by CEA, was introduced in early 1950s as a method to prevent stroke due to atherosclerosis of the carotid bifurcation and internal carotid artery (ICA). At least four prospective randomized trials have demonstrated... 

Candidates for carotid revascularization include patients with symptomatic carotid lesions and asymptomatic patients, usually diagnosed as the result of a screening procedure. In general, the indications for carotid revascularization are dependent on the symptomatic status of the patient and on lesion severity, and are similar for the endovascular and surgical strategies (Table I) (42-45),... 

CARESS Steering Committee (2005). Carotid Revascularization Using Endarterectomy or Stenting Systems (CARESS) phase I clinical trial 1-year results. Journal of Vascular Surgery 42 213-219... 

Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) (2006). Stroke 37 e36... 

Who Should be Considered for Screening for Asymptomatic CAS 166 Carotid Revascularization for Patients With Asymptomatic Carotid Artery Stenosis ... 

The cost-effectiveness of carotid revascularization (carotid endarterectomy [CEA] vs. carotid stenting)... 

Although carotid revascularization has been shown to confer benefit in reducing stroke risk over medical therapy in asymptomatic patients, the absolute benefit is... 

CAROTID REVASCULARIZATION FOR PATIENTS WITH ASYMPTOMATIC CAROTID ARTERY STENOSIS THE CONTROVERSY... 

This concern extends to carotid artery stenting. Although carotid artery stenting in patients with asymptomatic CAS can be performed by experienced operators with a low complication rate, the procedure can be associated with high complication rate if performed by inexperienced operators, particularly in older patients with complex anatomy (24). In any case, institution-specific assessment of the risk of carotid intervention, endarterectomy, or stenting should be a prime consideration in clinical decision making regarding carotid revascularization in patients with asymptomatic CAS. 

Most experts agree that certain patients with asymptomatic CAS are at high risk for stroke and may derive significant benefit from carotid revascularization. Identification of those patients, however, has been elusive in clinical trials. Risk stratification of patients with asymptomatic CAS is particularly important among patients with 60% to 79% stenosis, in whom the appropriate management is more uncertain. Identifying high-risk patients will certainly lead to better resource utilization for both medical and revascularization therapies for patients with asymptomatic CAS. 

Patients older than 80 years are at higher risk of stroke from carotid disease, as well as from other causes (25). These patients are also at higher risk of complications after carotid revascularization (24,26). The decision to proceed with carotid revascularization in octogenarians should be made on a case-by-case basis by... 

Therefore, until further evidence is available, selected women with asymptomatic CAS should be considered for carotid revascularization however, with two caveats the threshold for carotid revascularization should be higher in women than that in men and patients are counseled that there is more pronounced benefit for men compared with women undergoing CEA. 

Among patients with severe asymptomatic CAS, the presence of renal insufficiency and a history of contralateral neurological symptoms significantly increase the risk of future stroke. These patients should be considered for carotid revascularization (28). 

The higher the degree of carotid stenosis in neuro-logically asymptomatic individuals the higher the risk of stroke and TIA (28,31). Most experts agree that a critical threshold of >80% stenosis is associated with a rise of ipsilateral ischemic neurological events and should trigger an evaluation for carotid revascularization. Nonetheless, it should be clear that lesion severity is only one of many variables that have an impact on future stroke risk. 

Data on the prognostic significance of carotid plaque qualitative parameters in neurologically asymptomatic patients are either lacking (plaque ulceration) or conflicting (plaque echogenecity). Some studies have shown that echolucent carotid plaques are associated with a two- to fivefold increased risk for stroke. However, the clinical utility of these observations for triaging patients to carotid revascularization awaits prospective confirmation (33). 

Cerebral microembolic signals are detected by tran-scranial Doppler in 1% to 23% of patients with asymptomatic CAS (36-38). The prevalence of cerebral microembolic signals in patients with asymptomatic CAS varies with the severity of the carotid stenosis, the morphology of the carotid plaque, and the frequency and duration of transcranial Doppler monitoring. The presence of cerebral microembolic signals in patients with asymptomatic CAS has been associated with a risk of stroke increased four to five times (38). However, the clinical utility of this technique to discriminate among patients who will benefit from carotid revascularization versus those who would not awaits confirmation in prospective trials. 

Data regarding the role of CAS in low-surgical-risk patients with asymptomatic CAS are limited. The Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) lead-in registry has reported data for investigators during the roll-in phase (51). The 30-day rate of stroke and death in the 960 asymptomatic patients was 4.0%, and if limited to only patients under the age of 80 years is 3.3%. The 30-day rate of death and major stroke in patients under the age of 80 years was 1.4%. 

Roberts, H.C., W.P. Dillon, and W.S. Smith, Dynamic CT perfusion to assess the effect of carotid revascularization in chronic cerebral ischemia. AJNR Am J Neuroradiol, 2000. 21(2) p. 421-5. 

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