Comparison of the treatment strategies for symptomatic chronic internal carotid artery occlusion.

Objective: The best management of symptomatic chronic internal carotid artery occlusion (CICAO) has been controversial. This systematic review and meta-analysis were to compare the outcomes of different treatment strategies for symptomatic CICAO.

Methods: Two independent researchers conducted a search of articles on the treatment of CICAO published between January 2000 and October 2023 in PubMed, Web of Science, Embase, and The Cochrane Library. Twenty-two articles were eligible for meta-analysis using a random effects model to combine and analyze the data for the pooled rates of stroke and death, and the rates of procedural success and significant restenosis/occlusion.

Results: A total of 1193 patients from 22 publications were included in this study. Six of them had bilateral internal carotid artery occlusion. The 30-day stroke and death rates were 1.1% (95% confidence interval [CI], 0%-4.4%) in the best medical treatment (BMT) group, 4.1% (95% CI, 0.7%-9.3%; I² = 71.4%) in the extracranial-intracranial (EC-IC) bypass group, 4.4% (95% CI, 2.4%-6.8%; I² = 0%) in the carotid artery stenting (CAS) group, and 1.2% (95% CI, 0%-3.4%; I² = 0%) in the combined carotid endarterectomy (CEA) and stenting (CEA + CAS) group. During follow-up of 16.5 (±16.3) months, the stroke and death rates were 19.5%, 1.2%, 6.6%, and 2.4% in the BMT, EC-IC, CAS, and CEA + CAS groups respectively. The surgical success rate was 99.7% (95% CI, 98.5%-100%; I² = 0%) in the EC-IC group, 70.1% (95% CI, 62.3%-77.5%; I² = 64%) in the CAS group, and 86.4% (95% CI, 78.8%-92.7%; I² = 60%) in the CEA + CAS group. The rate of post-procedural significant restenosis or occlusion was 3.6% in the EC-IC group, 18.7% in the CAS group, and 5.7% in the CEA + CSA group. The surgical success rate was negatively associated by the length of internal carotid artery (ICA) occlusion. Surgical success rate was significantly higher in the patients with occlusive lesion within C1 to C4 segments, compared with those with occlusion distal to C4 segment (odds ratio, 11.3; 95% CI, 5.0-25.53; P < .001). A proximal stump of ICA is a favorable sign for CAS. The success rate of CAS was significantly higher in the patients with an ICA stump than that in the patients without (odds ratio, 11.36; 95% CI, 4.84-26.64; P < .01). However, the success rate of CEA + CAS was not affected by the proximal ICA stump.

Conclusions: For the management of symptomatic CICAO, BMT alone is associated with the highest risk of mid- and long-term stroke and death. EC-IC bypass surgery and CEA + CAS should be considered as the choice of treatment based on operator's expertise and patient's anatomy. CAS may be employed as an alternative option in high surgical risk patients, especially when proximal ICA stump exists.