Symptomatic carotid near-occlusion causes a high risk of recurrent ipsilateral ischemic stroke

Abstract

Objective: To assess the risk of recurrent ipsilateral ischemic stroke in patients with symptomatic near-occlusion with and without full collapse.

Methods: Included were consecutive patients eligible for revascularization, grouped into symptomatic conventional ≥ 50% carotid stenosis (n = 266), near-occlusion without full collapse (n = 57) and near-occlusion with full collapse (n = 42). The risk of preoperative recurrent ipsilateral ischemic stroke was analyzed, or, for cases not revascularized within 90 days, 90-day risk was analyzed.

Results: The risk of a preoperative recurrent ipsilateral ischemic stroke or ipsilateral retinal artery occlusion was 15% (95% CI 9-20%) for conventional ≥ 50% stenosis, 22% (95% CI 6-38%) among near-occlusion without full collapse and 30% (95% CI 16-44%) among near-occlusion with full collapse (p = 0.01, log rank test). In multivariate analysis, near-occlusion with full collapse had a higher risk of recurrent ipsilateral ischemic stroke (adjusted HR 2.6, 95% CI 1.3-5.3) and near-occlusion without full collapse tended to have a higher risk (adjusted HR 2.0, 95% CI 0.9-4.5) than conventional ≥ 50% stenosis. Only 24% of near-occlusion with full collapse underwent revascularization, common causes for abstaining were misdiagnosis as occlusion (31%), deemed surgically unfeasible (21%) and low perceived benefit (10%).

Conclusions: Symptomatic carotid near-occlusion has a high short-term risk of recurrent ipsilateral ischemic stroke, especially near-occlusion with full collapse.

Keywords: Carotid stenosis; Large vessel disease; Neurology; Stroke.

Fig. 1

Left-sided symptomatic near-occlusion without full collapse; patient suffered a recurrent ipsilateral stroke 5 days after the exam. a Coronal view. Left distal ICA (black arrow, 3.3 mm) is smaller than right distal ICA (white arrow, 4.4 mm) and similar to left ECA (black arrowhead, 3.3 mm). Stenosis is hard to visualize (white arrowhead). b Sagittal view. Stenosis (white arrowhead) somewhat better visualized; lumen at stenosis is tight though but still difficult to assess. Axial source images (not displayed here) are usually most reliable to assess stenosis severity and with other features. A severe stenosis causing flow reduction was the most reasonable explanation of the small distal left ICA, interpreted as near-occlusion

Fig. 2

Left-sided symptomatic near-occlusion with full collapse; patient suffered a recurrent ipsilateral stroke 7 days after the exam. Left-sided symptomatic near-occlusion with full collapse. a Coronal view. Left distal ICA (black arrow, 1.2 mm) is clearly smaller than right distal ICA (white arrow, 3.7 mm) and smaller than left ECA (black arrowhead, 3.8 mm). Stenosis not seen in this projection, as the lumen was out-of-plane and so small on the image. b Axial view of the stenosis (white arrowhead, 0.8 mm). No relevant stenosis in left ICA (black start)

Fig. 3

Kaplan–Meier analysis of the primary endpoint (recurrent ipsilateral ischemic stroke or retinal artery occlusion). Revascularization and death used as censors. Overall difference p = 0.012. Near-occlusion with full collapse compared to conventional ≥ 50% stenosis p = 0.003. Near-occlusion without compared to with full collapse p = 0.26. Near-occlusion without full collapse compared to conventional ≥ 50% stenosis p = 0.017. Abbreviations in patients at risk table: Conv ≥ 50% Sten: conventional ≥ 50% stenosis. NO with FC: near-occlusion with full collapse. NO without FC: near-occlusion without full collapse