Management of internal carotid artery near-occlusion: the need for updated evidence

Abstract

Near occlusion of internal carotid artery (ICA) is a rare and easily misdiagnosed condition and the decision for revascularisation still remains controversial. We conducted an updated meta-analysis in order to investigate outcomes after carotid endarterectomy (CEA), carotid artery stenting (CAS) or best medical treatment (BMT) in patients with near-occlusion of the ICA. We also aimed to investigate the role of time as a potential moderator of the near-ICA occlusion-stroke rate association. A multiple electronic health database search on articles published up to November 2019 was performed. The pooled stroke rate after CEA, CAS and BMT were calculated. We also investigated transient ischemic attack (TIA), stroke-related death, myocardial infarction (MI), any cause of death and ICA restenosis crude rates (%). A total of 33 articles were finally deemed eligible. The pooled stroke rate was 1.52% [95% confidence interval (CI): 0.09-4.02%] after CEA, 1.80% (95% CI: 0.61-3.40%) after CAS and 8.39% (95% CI: 3.39-14.80%) after BMT. Out of 896 CEA patients, we recorded 22 TIAs (2.5%), 33 all-cause deaths (3.7%), 5 stroke-related deaths (0.6%) and 6 MIs (0.7%). Concerning outcomes after 603 CAS patients, we recorded 7 TIAs (1.2%), 56 all-cause deaths (9.3%), 4 stroke-related deaths (0.7%) and 22 MIs (3.6%). Among 263 patients who were treated with BMT, we found 16 TIAs (6.1%), 10 all-cause deaths (3.8%), no stroke-related death, and no MI. Crude restenosis rate during follow-up was 9.0% (54/601) for CEA and 4.1% (24/592) for CAS patients. No significant effect of publication year upon stroke rate after CEA was recorded. However, there was a significant reversed association between pooled stroke rate after CAS and publication year (P=0.05). A statistically significant reversed association between pooled stroke rate after BMT and publication year was also recorded (P<0.01). The results of this updated meta-analysis revealed high stroke rate for patients with near-occlusion of ICA who treated only with BMT, while intervention seemed to be safe and effective. A downward trend in the stroke rates over time after CAS and BMT was also discovered. These highlight that patients with near-occlusion of ICA should be included and investigated in future studies.

Keywords: Carotid artery; meta-analysis; near occlusion; string sign; stroke.

Figure 1

Flow chart. BMT, best medical treatment; CEA, carotid endarterectomy; CAS, carotid artery stenting.

Figure 2

Forest plot presenting the meta-analysis of stroke rates after carotid endarterectomy (CEA). Event rates in the individual studies are presented as squares with 95% confidence intervals (CIs) presented as extending lines. The pooled event rate with its 95% CI is depicted as a diamond. ES, effect estimate.

Figure 3

Forest plot presenting the meta-analysis of stroke rates after carotid artery stenting (CAS). Event rates in the individual studies are presented as squares with 95% confidence intervals (CIs) presented as extending lines. The pooled event rate with its 95% CI is depicted as a diamond. ES, effect estimate.

Figure 4

Forest plot presenting the meta-analysis of stroke rates after best medical treatment (BMT). Event rates in the individual studies are presented as squares with 95% confidence intervals (CIs) presented as extending lines. The pooled event rate with its 95% CI is depicted as a diamond. ES, effect estimate.

Figure 5

Forest plot presenting the meta-regression of stroke rates after carotid endarterectomy (CEA) with publication year.

Figure 6

Forest plot presenting the meta-regression of stroke rates after carotid artery stenting (CAS) with publication year.

Figure 7

Forest plot presenting the meta-regression of stroke rates after best medical treatment (BMT) with publication year.