Functional Occlusions of the Carotid Artery (String Signs)

Carotid Near-Occlusion: A Comprehensive Review, Part 2--Prognosis and Treatment, Pathophysiology, Confusions, and Areas for Improvement

In Part 1 of this review, the definition, terminology, and diagnosis of carotid near-occlusion were presented. Carotid near-occlusions (all types) showed a lower risk of stroke than other severe stenoses. However, emerging evidence suggests that the near-occlusion prognosis with full collapse (higher risk) differs from that without full collapse (lower risk). This systematic review presents what is known about carotid near-occlusion. In this second part, the foci are prognosis and treatment, pathophysiology, the current confusion about near-occlusion, and areas in need of future improvement.

Carotid Near-Occlusion: A Comprehensive Review, Part 1--Definition, Terminology, and Diagnosis

Carotid near-occlusion is distal ICA luminal collapse beyond a tight stenosis, where the distal lumen should not be used for calculating percentage stenosis. Near-occlusion with full ICA collapse is well-known, with a threadlike lumen. However, near-occlusion without collapse is often subtle and can be overlooked as a usual severe stenosis. More than 10 different terms have been used to describe near-occlusion, sometimes causing confusion. This systematic review presents what is known about carotid near-occlusion. In this first part, the foci are definition, terminology, and diagnosis.

A lotus root-like appearance in carotid stenosis on optical coherence tomography

An 82-year-old man visited the outpatient clinic of our stroke centre because of dizziness. He had a previous history of stroke without definite sequelae. Severe stenosis in the left proximal internal carotid artery (ICA) was seen on Doppler sonography. Conventional angiography revealed focal severe stenosis with 'string sign' in the left proximal ICA and delayed distal run off. Optical coherence tomography showed multiple channels surrounding a narrowed central lumen (lotus root-like appearance). Carotid stent placement with a protection device was done without complications. The patient was discharged in good condition 5 days after the procedure.

A lotus root-like appearance in carotid stenosis on optical coherence tomography

An 82-year-old man visited the outpatient clinic of our stroke centre because of dizziness. He had a previous history of stroke without definite sequelae. Severe stenosis in the left proximal internal carotid artery (ICA) was seen on Doppler sonography. Conventional angiography revealed focal severe stenosis with 'string sign' in the left proximal ICA and delayed distal run off. Optical coherence tomography showed multiple channels surrounding a narrowed central lumen (lotus root-like appearance). Carotid stent placement with a protection device was done without complications. The patient was discharged in good condition 5 days after the procedure.

Carotid artery stenting: clinical and procedural implications for near-occlusion stenosis

INTRODUCTION AND OBJECTIVES

The advisability of implanting a stent in carotid near-occlusion stenosis is a controversial topic. We have assessed procedural and clinical implications of stent implantation for carotid artery disease with near occlusion.

METHODS

We included 205 patients who underwent carotid artery revascularisation with a stent. The group of patients with near-occlusion stenosis (n=54)was compared to the rest of the population (n=151).

RESULTS

No differences were found between groups for age, sex, and the percentage of symptomatic patients (three-quarters of the population). Carotid stent revascularisation for near-occlusion stenosis presented a high procedural success rate (96%) similar to that of revascularisation processes for other lesions (98%). Stenting in cases of near-occlusion stenosis required increased use of proximal protection (54% vs. 20.5%, P<.001) and predilation (33% vs. 17%, P=.01). The process to repair near-occlusion stenosis cause increased detachment of plaque, as shown by higher percentages of macroscopic plaque captured by protection devices (18.5% vs. 7%, P=.01) and of perioperative ischaemic brain lesions (47% vs 31%, P = .07). At 30 days of follow-up, the tendency toward adverse neurological events (death, major and minor stroke) was higher in the near-occlusion group (9.2% vs. 3.2%, P=.08).

CONCLUSIONS

Stent revascularisation for near-occlusion carotid stenosis has a high procedural success rate; however, its higher plaque load was responsible for the increased rate of ischaemic brain lesions and adverse neurovascular events at 30 days post-procedure.