Association for Academic SurgeryResults of carotid angioplasty and stenting are equivalent for critical versus high-grade lesions in patients deemed high risk for carotid endarterectomy
Introduction
Carotid angioplasty and stenting (CAS) has evolved as an effective strategy for stroke prevention in patients with extracranial carotid artery stenosis. Utilization of this endovascular technology has been the focus of extensive clinical investigation in recent years, with numerous randomized controlled trials demonstrating equivalent results when compared with carotid endarterectomy (CEA) [1], [2], [3], [4], [5], [6]. In the Carotid Revascularization Endarterectomy versus Stenting Trial, the risk of the composite primary outcomes of stroke, myocardial infarction (MI), or death did not differ significantly in the group undergoing CAS compared with those in the group undergoing CEA [1]. During the periprocedural period, however, CAS was found to be associated with a higher risk of stroke (4.1% versus 2.3%) and a lower risk of MI (1.1% versus 2.3%). Current recommendations by the Society for Vascular Surgery cite CAS as the preferred treatment modality in symptomatic patients with ≥50% stenosis who are deemed high risk for CEA based on medical comorbidities or specific high-risk anatomic features [7].
Although the link between embolic stroke risk and carotid artery stenosis was first suggested in 1951 [8], the details pertaining to the escalation of this risk with increasing severity of carotid lesions were not articulated until more recently [9], [10], [11]. Norris and Zhu [9] plotted the frequency distribution of carotid stenosis in 500 patients with asymptomatic carotid bruits and related this to the risk of ischemic cerebral events and the corresponding progression of arterial lesions. Their results failed to show the anticipated theoretical frequency distribution of a continuous variable such as severity of carotid stenosis; instead, the authors demonstrated a maximal stroke risk at 75%–90% stenosis. Such a finding is consistent with a flow model of the carotid bifurcation constructed by Spencer and Reid [12] which showed that blood flow remains constant and blood velocity increases with progressive luminal narrowing up to approximately 80%, after which point both values abruptly decline. Therefore, the risk of cerebral ischemia in stenosis greater than some threshold value, likely in the range of 80%–90%, appears to be more a function of hemodynamic status and less of thromboembolic potential.
It remains unclear, however, whether increasing severity of carotid stenosis translates into greater risk of periprocedural thromboembolic complications after CAS. Indeed, the safety and efficacy of endovascular carotid intervention in patients based on varying degrees of carotid stenosis have not been fully explored. Stroke is the most feared complication of CAS, and there exists a theoretical concern that higher degrees of carotid stenosis may portend a worse periprocedural outcome because of manipulation of the severely narrowed arterial lumen. We aim to evaluate the periprocedural and mid-term outcomes of CAS in patients with high-grade and critical carotid stenosis.
Section snippets
Patient selection
A retrospective review of all patients undergoing CAS procedures between 2002 and 2011 at an academic medical center was performed. Eligibility criteria included patients with symptomatic carotid stenosis of ≥70% or asymptomatic carotid stenosis of ≥80% in combination with either significant comorbid status and/or one or more of the following high-risk anatomic factors: high carotid artery bifurcation (above the level of the second cervical vertebrae), previous CEA, presence of tracheostomy,
Results
A total of 257 CAS procedures were performed in 245 patients during the 9-y study period. Fifty-one percentage (n = 130) of cases involved critical stenosis (66.2% male; mean age, 71 ± 10 y), with the remaining group (n = 127) involving high-grade stenosis (67.7% male; mean age, 71 ± 9 y). Cardiovascular risk factors were frequently encountered in both groups (Table 1). Chronic obstructive pulmonary disease was more common among patients in the high-grade stenosis group (19.7% versus 8.5%, P =
Discussion
The present study serves as only the second of its kind to critically analyze the results of CAS procedures in a contemporary series of patients based on the degree of underlying carotid stenosis. Our findings suggest that patients with critical carotid stenosis are able to undergo CAS procedures safely and with no significant differences in the incidence of stroke, MI, or death relative to similar patients with lesser degrees of carotid stenosis. Moreover, patients with critical stenosis were
Conclusions
Our data indicate that CAS with embolic protection may be performed safely in patients deemed high risk for CEA and with critical stenosis. We found no significant patient characteristics or procedural differences to suggest that patients with critical carotid stenosis are at any increased risk for periprocedural adverse clinical events. Patients with high-grade and critical stenosis are capable of achieving similar periprocedural outcomes and mid-term prognosis.
References (29)
- et al.
Endarterectomy Versus Angioplasty in Patients with Symptomatic Severe Carotid Stenosis (EVA-3S) trial: results up to 4 years from a randomised, multicentre trial
Lancet Neurol
(2008) - et al.
Results of the Stent-Protected Angioplasty versus Carotid Endarterectomy (SPACE) study to treat symptomatic stenoses at 2 years: a multinational, prospective, randomised trial
Lancet Neurol
(2008) - et al.
Long-term results of 442 consecutive, standardized carotid endarterectomy procedures in standard-risk and high-risk patients
J Vasc Surg
(2007) - et al.
Updated Society for Vascular Surgery guidelines for management of extracranial carotid disease: executive summary
J Vasc Surg
(2011) - et al.
Carotid artery stenting with proximal cerebral protection for patients with angiographic appearance of string sign
JACC Cardiovasc Interv
(2010) - et al.
Carotid artery stenting is associated with increased complications in octogenarians: 30-day stroke and death rates in the CREST lead-in phase
J Vasc Surg
(2004) - et al.
The impact of increasing age on anatomic factors affecting carotid angioplasty and stenting
J Vasc Surg
(2007) - et al.
Angiographic lesion characteristics can predict adverse outcomes after carotid artery stenting
J Vasc Surg
(2008) - et al.
Analysis of anatomic factors and age in patients undergoing carotid angioplasty and stenting
Ann Vasc Surg
(2005) - et al.
Periprocedural complication rates are equivalent between symptomatic and asymptomatic patients undergoing carotid angioplasty and stenting
Ann Vasc Surg
(2008)
Stenting versus endarterectomy for treatment of carotid-artery stenosis
N Engl J Med
International carotid stenting study: protocol for a randomised clinical trial comparing carotid stenting with endarterectomy in symptomatic carotid artery stenosis
Cerebrovasc Dis
Endovascular versus surgical treatment in patients with carotid stenosis in the Carotid and Vertebral Artery Transluminal Angioplasty Study (CAVATAS): a randomised trial
Lancet
The effect of inhalational anesthetic agents on the myocardium of the dog
Anesthesiology
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Presented at the 8th Annual Academic Surgical Congress, New Orleans, Louisiana, February 5–7, 2013.