Association for Academic Surgery
Results of carotid angioplasty and stenting are equivalent for critical versus high-grade lesions in patients deemed high risk for carotid endarterectomy

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Abstract

Background

To examine outcomes of carotid angioplasty and stenting (CAS) in patients with critical carotid stenosis who are deemed high risk for carotid endarterectomy.

Methods

Medical records were retrospectively analyzed for patients undergoing CAS between September 2002 and March 2011 at a single institution. Patients were classified as having either critical (≥90%) or high-grade (70%–89%) carotid stenosis based on angiography. The primary composite end point was stroke, myocardial infarction, or death from any cause during the periprocedural period or any ipsilateral stroke during the follow-up period.

Results

A total of 245 patients underwent 257 CAS procedures during the 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). Symptomatic carotid disease was present in 25% of the critical stenosis and 31% of the high-grade stenosis groups (P = 0.33). Chronic obstructive pulmonary disease was more commonly found in the high-grade stenosis group (20% versus 8%, P = 0.01). No difference was observed between the groups relative to other baseline demographic characteristics, presence of contralateral carotid occlusion, stent diameter or length, maximum balloon diameter or length, use of embolic protection device, or procedural duration. Technical success was achieved in all cases. There was no difference in the need to predilate before the introduction of the filter or stent based on the degree of stenosis. We found no difference in the primary composite end point between the high-grade or critical stenosis groups (7.1% versus 7.7%, P = 0.74), or there were no differences between the individual components of the composite end point. Mid-term survival was similar between the two groups at a mean follow-up period of 2.4 y.

Conclusions

Despite concerns regarding the potential for increased neurologic complications, our data demonstrate that patients with high-grade and critical stenosis are able to safely undergo CAS and achieve similar periprocedural outcomes and mid-term prognosis.

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)

  • T.G. Brott et al.

    Stenting versus endarterectomy for treatment of carotid-artery stenosis

    N Engl J Med

    (2010)
  • R.L. Featherstone et al.

    International carotid stenting study: protocol for a randomised clinical trial comparing carotid stenting with endarterectomy in symptomatic carotid artery stenosis

    Cerebrovasc Dis

    (2004)
  • CAVATAS investigators

    Endovascular versus surgical treatment in patients with carotid stenosis in the Carotid and Vertebral Artery Transluminal Angioplasty Study (CAVATAS): a randomised trial

    Lancet

    (2001)
  • C.W. Fisher et al.

    The effect of inhalational anesthetic agents on the myocardium of the dog

    Anesthesiology

    (1951)
  • Presented at the 8th Annual Academic Surgical Congress, New Orleans, Louisiana, February 5–7, 2013.

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